jcinvest00346-0039

5
THE MINERAL CONTENT O F NORMAL HUMAN BONE B y JAMES W . AGNA,2 HARVEY C . KNOWLES, JR. A N D GABRIELE ALVERSON  From the Metabolism Laboratory, Department o f Medicine, University o f Cincinnati College o f Medicine, a n d the Veterans Administration Hospital, Cincinnati, Ohio Submitted for publication February 14 , 1958; accepted June 1 , 1958 Evidence h a s been forthcoming from animal experimentation that t h e skeleton m a y gain o r lose electrolytes under conditions o f abnormal electro- lyte metabolism  1 . A complete evaluation o f t h e significance o f these findings i n m an depends upon knowledge o f t h e composition o f normal h u - m an bone. However, information regarding h u - ma n bone i s sparse. I n 1894, Gabriel, i n a very detailed study o f animal bone, included t wo repre- sentative samples from a n unstated number o f specimens o f humerus o f m a n  2 . Klement, i n 1936, also conducted a comprehensive investigation o f mineral content, b u t h i s material w a s limited t o three samples o f skull, a n d t w o each o f pelvis a n d femur  3 . I n recent years, further reports o f human bone composition have appeared  4-12 . However, these latter observations have n o t been wholly satisfactory, i n that t h e number o f samples analyzed were f e w a n d t h e determinations were limited t o t w o or three minerals. Furthermore, a majority o f t h e subjects in these reports from whom bone specimens were obtained either died with disease, o r specific statements concerning t h e condition o f t h e subjects prior t o death were no t given. T h e largest study currently reported i s that given i n abstract form b y Pellegrino a nd Farber  1 3 . These workers analyzed tibial bone o f 1 5 normal subjects f o r C a , P , Na a n d K . T h e present study i s concerned with t h e compo- sition o f bone obtained at autopsy from 1 6 normal adults w ho died suddenly. A comparative analysis o f skull, r ib a nd ilium, f o r water, calcium, phos- phorus, carbonate, nitrogen, chloride, potassium a nd sodium i s given. 1 Supported by Grant H 1445 from th e National I n - stitutes o f United States Public Health Service. 2 Clinical Investigator, Veterans Administration Hos- pital Cincinnati, Ohio. This work commenced during a United States Public Health Service Postdoctoral R e - search Fellowship, 1955-1957. METHODS Thirty-seven bone specimens  skull, rib, ilium were obtained from 1 6 human subjects w h o came to autopsy 2 t o 1 2 hours post mortem. T h e subjects died suddenly and were believed t o b e i n normal health prior t o the fatal episode. T h e causes o f death included electrocu- tion, subarachnoid hemorrhage, stab a n d gunshot wounds, strangling, a n d head injury. No abnormal conditions other than those causing death were disclosed a t necropsy. There w a s n o evidence of bone disorder. The mean a g e of the subjects w a s 3 5 years  range, 2 3 t o 6 2 . Samples of bone were obtained with a s a w from the occipital area o f t he skull, t h e iliac crest, a n d t h e a n - terior third of t h e ribs lateral to t h e sternal cartilage. T h e bone was stripped of muscle attachments a n d peri- osteum a n d broken into fragments with a mallet. Mar- w a s removed a s completely as possible b y scraping. T h e specimens were dried at 1050 C . f o r 96 hours t o determine t h e water content. It i s possible that further water loss would have occurred with heating t o higher temperatures  1 4 . T h e dried material w a s then r e - duced t o a powder b y passing i t through a Wiley mill, using a 2 0 mesh. F a t was extracted from the powdered sample i n a Soxhlet apparatus with reflux f o r s i x hours each with ethyl ether a n d petroleum ether. T w o hun- dred fifty t o 3 0 0 m g . a iquots of t h e fat-free material were then dry-ashed i n platinum crucibles overnight i n a muffle furnace a t 5250 C . T h e a s h wa s dissolved i n 1. 5 m l . o f 3 N HCl. This solution w a s then subjected t o column separation as recommended b y Forbes a n d D Ambruso  1 5 . Fo r preparation of the columns, dried sulfonated polys- terene resin  Dowex 5 0 X 1 2 , 5 0 t o 1 0 0 mesh) w a s mixed with a small amount o f water f o r convenience of handling a n d introduced t o a height o f 4 5 cm . i n burettes 1 . 2 cm. in diameter a n d 60 cm. i n height. T h e columns were washed with 300 ml . o f 0 . 7 N H C l prior t o infusion o f t h e sample. T h e bone a s h w a s transferred t o the resin b e d i n a volume o f approximately 10 ml. a n d elu- tion with 0 . 7 N H C l a t a flow rate of 2 . 0 + 0 . 5 ml. p e r minute was carried out. T h e first 1 0 0 m l . o f the eluate was used f o r P analysis according t o Fiske a n d Subbarow  1 6 . T h e 1 0 0 t o 3 0 0 ml . fraction w a s utilized for Na analysis. T h e elutriant w a s then changed t o 5 N HCO, a n d t h e 3 0 0 t o 5 0 0 ml. fraction collected for determina- tion of C a a nd K. T h e latter t w o elution fractions were evaporated over a steam bath a n d made t o volume fo r flame spectrometric determination o f N a , C a an d K , u s - ing a Weichselbaum-Varney photometer. T h e column 1357

Upload: truti

Post on 14-Apr-2018

215 views

Category:

Documents


0 download

TRANSCRIPT

Page 1: jcinvest00346-0039

7/27/2019 jcinvest00346-0039

http://slidepdf.com/reader/full/jcinvest00346-0039 1/5

THE MINERAL CONTENT OF NORMAL HUMAN BONE'

B y JAMES W . A G N A , 2 HARVEY C . KNOWLES, J R . , A N D GABRIELE ALVERSON

( F r o m t h e M e t a b o l i s m L a b o r a t o r y , D e p a r t m e n t o f M e d i c i n e , U n i v e r s i t y o f C i n c i n n a t i C o l l e g e

o f M e d i c i n e , a n d t h e V e t e r a n s A d m i n i s t r a t i o n H o s p i t a l , C i n c i n n a t i , O h i o )( S u b m i t t e d f o r p u b l i c a t i o n F e b r u a r y 1 4 , 1 9 5 8 ; a c c e p t e d J u n e 1 2 , 1 9 5 8 )

E v i d e n c e h a s b e e n f o r t h c o m i n g f r o m a n i m a l

e x p e r i m e n t a t i o n t h a t t h e s k e l e t o n may g a i n o r l o s e

e l e c t r o l y t e s u n d e r c o n d i t i o n s o f a b n o r m a l e l e c t r o -

l y t e m e t a b o l i s m ( 1 ) . A c o m p l e t e e v a l u a t i o n o f

t h e s i g n i f i c a n c e o f t h e s e f i n d i n g s i n m a n d e p e n d s

u p o n k n o w l e d g e o f t h e c o m p o s i t i o n o f n o r m a l h u -

man b o n e . H o w e v e r , i n f o r m a t i o n r e g a r d i n g h u -

man b o n e i s s p a r s e . I n 1 8 9 4 , G a b r i e l , i n a v e r y

d e t a i l e d s t u d y o f a n i m a l b o n e , i n c l u d e d t w o r e p r e -

s e n t a t i v e s a m p l e s f r o m a n u n s t a t e d n u m b e r o f

s p e c i m e n s o f h u m e r u s o f m an ( 2 ) . K l e m e n t , i n

1 9 3 6 , a l s o c o n d u c t e d a c o m p r e h e n s i v e i n v e s t i g a t i o n

o f m i n e r a l c o n t e n t , b u t h i s m a t e r i a l w a s l i m i t e d t o

t h r e e s a m p l e s o f s k u l l , a n d t w o e a c h o f p e l v i s a n d

f e m u r ( 3 ) . I n r e c e n t y e a r s , f u r t h e r r e p o r t s o f

h u m a n b o n e c o m p o s i t i o n h a v e a p p e a r e d ( 4 - 1 2 ) .H o w e v e r , t h e s e l a t t e r o b s e r v a t i o n s h a v e n o t b e e n

w h o l l y s a t i s f a c t o r y , i n t h a t t h e n u m b e r o f s a m p l e s

a n a l y z e d w e r e f e w a n d t h e d e t e r m i n a t i o n s w e r el i m i t e d t o t w o o r t h r e e m i n e r a l s . F u r t h e r m o r e ,

a m a j o r i t y o f t h e s u b j e c t s i n t h e s e r e p o r t s f r o m

whom b o n e s p e c i m e n s w e r e o b t a i n e d e i t h e r d i e d

w i t h d i s e a s e , o r s p e c i f i c s t a t e m e n t s c o n c e r n i n g t h e

c o n d i t i o n o f t h e s u b j e c t s p r i o r t o d e a t h w e r e n o t

g i v e n . T h e l a r g e s t s t u d y c u r r e n t l y r e p o r t e d i s

t h a t g i v e n i n a b s t r a c t f o r m b y P e l l e g r i n o a n d

F a r b e r ( 1 3 ) . T h e s e w o r k e r s a n a l y z e d t i b i a l b o n e

o f 1 5 n o r m a l s u b j e c t s f o r C a , P , Na a n d K .

T h e p r e s e n t s t u d y i s c o n c e r n e d w i t h t h e c o m p o -

s i t i o n o f b o n e o b t a i n e d a t a u t o p s y f r o m 1 6 n o r m a l

a d u l t s w h o d i e d s u d d e n l y . A c o m p a r a t i v e a n a l y s i s

o f s k u l l , r i b a n d i l i u m , f o r w a t e r , c a l c i u m , p h o s -p h o r u s , c a r b o n a t e , n i t r o g e n , c h l o r i d e , p o t a s s i u ma n d s o d i u m i s g i v e n .

1 S u p p o r t e d b y G r a n t H 1 4 4 5 f r o m t h e N a t i o n a l I n -

s t i t u t e s o f H e a l t h , U n i t e d S t a t e s P u b l i c H e a l t h S e r v i c e .2 C l i n i c a l I n v e s t i g a t o r , V e t e r a n s A d m i n i s t r a t i o n H o s -

p i t a l , C i n c i n n a t i , O h i o . T h i s w o r k c o m m e n c e d d u r i n ga U n i t e d S t a t e s P u b l i c H e a l t h S e r v i c e P o s t d o c t o r a l R e -

s e a r c h F e l l o w s h i p , 1 9 5 5 - 1 9 5 7 .

METHODS

T h i r t y - s e v e n b o n e s p e c i m e n s ( s k u l l , r i b , i l i u m ) w e r e

o b t a i n e d f r o m 1 6 h u m a n s u b j e c t s who c a m e t o a u t o p s y

2 t o 1 2 h o u r s p o s t m o r t e m . T h e s u b j e c t s d i e d s u d d e n l y

a n d w e r e b e l i e v e d t o b e i n n o r m a l h e a l t h p r i o r t o t h ef a t a l e p i s o d e . T h e c a u s e s o f d e a t h i n c l u d e d e l e c t r o c u -t i o n , s u b a r a c h n o i d h e m o r r h a g e , s t a b a n d g u n s h o t w o u n d s ,

s t r a n g l i n g , a n d h e a d i n j u r y . No a b n o r m a l c o n d i t i o n so t h e r t h a n t h o s e c a u s i n g d e a t h w e r e d i s c l o s e d a t n e c r o p s y .

T h e r e w a s n o e v i d e n c e o f b o n e d i s o r d e r . T h e m e a n a g eo f t h e s u b j e c t s w a s 3 5 y e a r s ( r a n g e , 2 3 t o 6 2 ) .

S a m p l e s o f b o n e w e r e o b t a i n e d w i t h a s a w f r o m t h eo c c i p i t a l a r e a o f t h e s k u l l , t h e i l i a c c r e s t , a n d t h e a n -

t e r i o r t h i r d o f t h e r i b s l a t e r a l t o t h e s t e r n a l c a r t i l a g e .T h e b o n e w a s s t r i p p e d o f m u s c l e a t t a c h m e n t s a n d p e r i -o s t e u m a n d b r o k e n i n t o f r a g me n t s w i t h a m a l l e t . M a r -

r o w w a s r e m o v e d a s c o m p l e t e l y a s p o s s i b l e b y s c r a p i n g .T h e s p e c i m e n s w e r e d r i e d a t 1 0 5 0 C . f o r 9 6 h ou rs t o

d e t e r m i n e t h e w a t e r c o n t e n t . I t i s p o s s i b l e t h a t f u r t h e rw a t e r l o s s w o u l d h a v e o c c u r r e d w i t h h e a t i n g t o h i g h e r

t e m p e r a t u r e s ( 1 4 ) . T h e d r i e d m a t e r i a l w a s t h e n r e -d u c e d t o a p o w d e r b y p a s s i n g i t t h r o u g h a W i l e y m i l l ,

u s i n g a 2 0 m e s h . F a t w a s e x t r a c t e d f r o m t h e p o w d e r e ds a m p l e i n a S o x h l e t a p p a r a t u s w i t h r e f l u x f o r s i x h o u r s

e a c h w i t h e t h y l e t h e r a n d p e t r o l e u m e t h e r . Two h u n -

d r e d f i f t y t o 3 0 0 m g . a l i q u o t s o f t h e f a t - f r e e m a t e r i a l

w e r e t h e n d ry - a s h e d i n p l a t i n u m c r u c i b l e s o v e r n i g h t i na m u f f l e f u r n a c e a t 5 2 5 0 C . T h e a s h w a s d i s s o l v e d i n1 . 5 m l . o f 3 N H C l . T h i s s o l u t i o n w a s t h e n s u b j e c t e dt o c o l u m n s e p a r a t i o n a s r e c o m m e n d e d b y F o r b e s a n d

D ' A m b r u s o ( 1 5 ) .F o r p r e p a r a t i o n o f t h e c o l u m n s , d r i e d s u l f o n a t e d p o l y s -

t e r e n e r e s i n ( D o w e x 5 0 X 1 2 , 5 0 t o 1 0 0 m e s h ) w a s

m i x e d w i t h a s m a l l a m o u n t o f w a t e r f o r c o n v e n i e n c e o fh a n d l i n g a n d i n t r o d u c e d t o a h e i g h t o f 4 5 c m . i n b u r e t t e s1 . 2 c m . i n d i a m e t e r a n d 6 0 c m . i n h e i g h t . T h e c o l u m n s

w e r e w a s h e d w it h 3 0 0 m l . o f 0 . 7 N H C l p r i o r t o i n f u s i o no f t h e s a m p l e . T h e b o n e a s h w a s t r a n s f e r r e d t o t h er e s i n b e d i n a v o l u m e o f a p p r o x i m a t e l y 1 0 m l . a n d e l u -

t i o n w i t h 0 . 7 N H C l a t a f l o w r a t e o f 2 . 0 + 0 . 5 m l . p e r

m i n u t e w a s c a r r i e d o u t . T h e f i r s t 1 0 0 m l . o f t h e e l u a t e

w a s u s e d f o r P a n a l y s i s a c c o r d i n g t o F i s k e a n d S u b b a r o w

( 1 6 ) . T h e 1 0 0 t o 3 0 0 m l . f r a c t i o n w a s u t i l i z e d f o r Na

a n a l y s i s . T h e e l u t r i a n t w a s t h e n c h a n g e d t o 5 N H C O ,

a n d t h e 3 0 0 t o 5 0 0 m l . f r a c t i o n c o l l e c t e d f o r d e t e r m i n a -

t i o n o f C a a n d K . T h e l a t t e r t w o e l u t i o n f r a c t i o n s w e r e

e v a p o r a t e d o v e r a s t e a m b a th a n d m a d e t o v o l u m e f o r

f l a m e s p e c t r o m e t r i c d e t e r m i n a t i o n o f N a , C a a n d K , u s -

i n g a W e i c h s e l b a u m - V a r n e y p h o t o m e t e r . T h e c o l u m n

1 3 5 7

Page 2: jcinvest00346-0039

7/27/2019 jcinvest00346-0039

http://slidepdf.com/reader/full/jcinvest00346-0039 2/5

JAMES W . AGNA, HARVEY C . KNOWLES, J R . , AND GABRIELE ALVERSON

TABLE I

T h e c o m p o s i t i o n o f n o r m a l s k u l l , r i b a n d i l i u m *

P e r k i l o g r a m d r y , f a t - f r e e b o n eH2 0 F a t

N o . ( w e t b o n e ) ( d r y b o n e ) H2 0 Ca P COs N C l K Na% % Gm. E q . Gm. E q . Gm . mEq. mEq. m E q .

S k u l l ( 1 0 ) 1 7 . 6 4 . 2 2 2 9 1 2 . 5 1 1 1 . 1 1 . 7 0 4 8 . 1 2 8 . 3 1 6 . 4 2 9 13 . 7 2 . 9 6 3 0 . 2 7 3 . 7 0 . 0 6 4 . 5 6 . 1 6 . 8 6 . 8

R i b ( 1 4 ) 2 1 . 6 6 . 4 3 1 9 1 1 . 6 1 0 4 . 5 1 . 6 3 5 3 . 4 3 5 . 3 3 4 . 0 2 6 86 . 4 5 . 3 1 4 3 0 . 4 7 4 . 7 0 . 1 0 3 . 1 9 . 0 1 1 . 6 8 . 3

I l i u m ( 1 3 ) 2 5 . 8 1 4 . 1 4 4 8 1 1 . 4 1 0 0 . 5 1 . 6 1 5 6 . 0 4 1 . 1 3 8 . 9 2 6 94 . 0 7 . 3 1 3 9 0 . 6 4 5 . 1 0 . 0 8 3 . 9 8 . 6 9 . 4 1 0 . 8

* V a l u e s g i v e n a r e mean a n d s t a n d a r d d e v i a t i o n .

w a s w a s h e d w i t h 3 0 0 m l . o f 0 . 7 N HC O a f t e r e a c h r u n .R e p o u r i n g o f t h e c ol u mn w a s u s u a l l y n e c e s s a r y a f t e r

t w o r u n s . Ne w r e s i n w a s e m p l o y e d a f t e r s i x r u n s .R e s i n s e p a r a t i o n o f i o n s w a s f o u n d t o b e e s s e n t i a l b e -c a u s e o f s p e c t r a l i n t e r f e r e n c e o f P a n d C a i n d e t e r m i n a -

t i o n o f N a , a n e f f e c t n o t e d a l s o b y o t h e r s ( 1 7 - 1 9 ) . I n

c o n t r a s t , n o m u t u a l i n t e r f e r i n g e f f e c t s o f C a a n d K w e r e

f o u n d . A v e r a g e r e c o v e r y v a l u e s f r o m s y n t h e t i c m i x t u r e s

p a s s e d t h r o u g h t h e r e s i n c o l u m n s w e r e : P , 9 8 . 6 p e r c e n t ;C a , 9 9 . 9 p e r c e n t ; N a , 9 9 . 1 p e r c e n t ; a n d K , 1 0 1 . 6 p e r

c e n t .

A l i q u o t s o f f a t - f r e e p o w d e r w e r e a n a l y z e d f o r c h l o -r i d e i n d u p l i c a t e a c c o r d i n g t o C h e e k a n d West ( 2 0 ) , f o r

c a r b o n a t e i n t r i p l i c a t e a c c o r d i n g t o B e r g s t r o m ( 2 1 ) , a n d

f o r t o t a l n i t r o g e n i n d u p l i c a t e b y t h e m i c r o - K j e l d a h l

m e t h o d .

A n a l y s i s o f f a t - f r e e p o w d e r i n d u p l i c a t e a g r e e d w i t h i n 2

p e r c e n t f o r N a , 4 p e r c e n t f o r K , 3 p e r c e n t f o r C a , 2 p e r

c e n t f o r P , 3 p e r c e n t f o r C l , a n d 2 p e r c e n t f o r n i t r o g e n .T r i p l i c a t e a n a l y s e s o f c a r b o n a t e w e r e m a d e , s i n c e t h e

d i f f e r e n c e s b e t w e e n i n d i v i d u a l a l i q u o t s o c c a s i o n a l l yr a n g e d t o 6 p e r c e n t . A n a l y s e s o f d a t a w e r e made a c -

c o r d i n g t o S n e d e c o r ( 2 2 ) .I t i s p o s s i b l e t h a t p o s t m o r t e m c h a n g e s o f pH o r o f

s o m e o t h e r n a t u r e m i g h t a l t e r b o n e c o m p o s i t i o n . How-

TABLE I I

T h e v a r i a n c e r a t i o s ( F ) o f m e a n s o f s u b j e c t s a n d b o n e s *

S u b j e c t s B o n e s

Ca 1 . 0 4 9 . 2 2 tP 1 1 . 5 t 1 1 3 tC 0 3 4 1 . 1 2 4 . 3 7 §Na 2 . 1 4 2 3 . 7 tN 1 . 8 7 3 9 . 7 tH 2 0 0 . 9 1 1 8 . 2 tK 1 . 1 9 2 1 . 2 tC l 6 . 3 0 t 2 3 . 1 t

* D e g r e e s o f f r e e d o m i n c l u d e 5 f o r s u b j e c t s , 2 f o r b o n e s ,1 0 f o r i n t e r a c t i o n , a n d 1 8 f o r a n a l y t i c a l e r r o r .

t S i g n i f i c a n t a t t h e 1 p e r c e n t l e v e l .t I n r e g a r d t o C 0 3 , t r i p l i c a t e a n a l y s e s w e r e m a d e , a n d

t h e d e g r e e s o f f r e e d o m f o r e r r o r w e r e 3 6 .

§ S i g n i f i c a n t a t t h e 5 p e r c e nt l e v e l .

e v e r , i t i s b e l i e v e d t h a t f a i l u r e o f t h e c i r c u l a t i o n w o u l d

p r e c l u d e s i g n i f i c a n t r e m o v a l o f a n y s u b s t a n c e s f r o m t h e

a r e a s a n a l y z e d .

RESULTS

I n T a b l e I a r e g i v e n t h e m e a n c o n c e n t r a t i o n s o f

w a t e r a n d m i n e r a l s e x p r e s s e d p e r k i l o g r a m o f f a t -

f r e e s o l i d s i n s k u l l , r i b a n d i l i u m . I n c o m p a r i s o n

t o i l i u m , s k u l l w a s c h a r a c t e r i z e d b y s i g n i f i c a n t l yg r e a t e r a m o u n t s o f C a , P , CO3 a n d N a , a n d l e s s e r

a m o u n t s o f H 2 O , N , C 1 a n d K ( p < 0 . 0 2 ) . The

c o n c e n t r a t i o n s i n r i b r a n g e d b e t w e e n t h o s e o f s k u l l

a n d i l i u m . T h e s e f i n d i n g s a re p r o b a b l y r e l a t e dt o t h e c o m p a c t n a t u r e o f s k u l l a s c o n t r a s t e d t o t h e

c a n c e l l o u s n a t u r e o f i l i u m , w i t h t h e s p e c i m e n s o fr i b o c c u p y i n g i n t e r m e d i a t e p o s i t i o n s i n d e n s i t y .B e c a u s e t h e b o n e s c o m p a r e d w e r e n o t a l w a y s o b -

t a i n e d f r o m t h e s a m e s u b j e c t s , a c h e c k o f t h e f i n d -

i n g s w a s m a d e w i t h v a r i a n c e a n a l y s i s i n o r d e r t o

e l i m i n a t e t h e e f f e c t s o f p a t i e n t v a r i a n c e o n t h e

m e a n s o f b o n e s ( T a b l e I I ) . I n s i x s u b j e c t s f r o m

whom a l l t h r e e b o n e s w e r e o b t a i n e d , t h e s a m e d i f -

f e r e n c e s b e t w e e n s k u l l a n d i l i u m w e r e f o u n d e x -

c e p t i n t h e c a s e o f c a r b o n a t e , w h e r e t h e c o n c e n t r a -

t i o n w a s o n l y p r o b a b l y d e c r e a s e d b e l o w t h a t o f

s k u l l ( p < 0 . 0 5 ) . I n t h e s a m e a n a l y s i s , n o d i f -f e r e n c e s i n c o n c e n t r a t i o n s o f m i n e r a l s b e t w e e n

p a t i e n t s w e r e f o u n d e x c e p t f o r t h o s e o f P a n d C l .

T h e d a t a o b t a i n e d a r e i n g e n e r a l a g r e e m e n t

w i t h t h o s e p u b l i s h e d b y o t h e r s . T h e amounts o f

w a t e r f o u n d a r e s i m i l a r t o t h o s e r e p o r t e d b y E d e l -

m a n , J a m e s , B a d e n a n d M o o r e when t h e l a r g ev a r i a n c e i s c o n s i d e r e d ( 1 1 ) . The c o n c e n t r a t i o n s

o f C a , P a n d C O 3 f o u n d a g r e e c l o s e l y w i t h t h o s e

r e p o r t e d e l s e w h e r e ( 5 , 9 - 1 1 , 1 3 ) . D e s p i t e t h e d i f -

f e r e n c e s i n C a a n d P c o n c e n t r a t i o n s b e t w e e n

b o n e s , t h e m o l a r C a t o P r a t i o s were 1 . 7 6 , 1 . 7 2

1 3 5 8

Page 3: jcinvest00346-0039

7/27/2019 jcinvest00346-0039

http://slidepdf.com/reader/full/jcinvest00346-0039 3/5

THE MINERAL CONTENT OF NORMAL HUMAN BONE

TABLE I I I

H u m a n b o n e sodium-mean c o n c e n t r a t i o n ( m E q . p e r k i l o g r a m o f d r y b o n e ) a n d n u m b e r o f s a m p l e s *

R e f e r -A u t h o r e n c e S k e l e t o n S k u l l R i b I l i u m Femur Humerus T i b i a V e r t e b r

G a b r i e l , 1 8 9 4 t ( 2 ) 2 5 1 ( 2 )K l e m e n t , 1 9 3 6 t ( 3 ) 1 5 9 ( 3 ) 1 3 1 ( 2 ) 1 4 0 ( 2 )

( p e l v i s )D a v i e s , K o r n b e r g a n d

W i l s o n , 1 9 5 2 t ( 8 ) 2 3 9 ( 1 0 ) 3 0 0 ( 6 )E d e l m a n , J a m e s , B a d e n

a n d M o o r e , 1 9 5 4 § ( 1 1 ) 2 7 3 ( 2 ) 2 1 5 ( 4 ) 2 2 2 ( 4 ) 2 4 6 ( 5 ) 2 1 5 ( 1 )F o r b e s a n d L e w i s ,

1 9 5 6 § ( 1 2 ) 3 0 9 ( 2 )P e l l e g r i n o a n d F a r b e r ,

1 9 5 8 t ( 1 3 ) 2 4 8 ( 1 5 )P r e s e n t s t u d y § 2 9 1 ( 1 0 ) 2 6 8 ( 1 4 ) 2 6 9 ( 1 3 )

* Numbers i n p a r e n t h e s e s i n d i c a t e n u m b e r s o f s a m p l e s .

t A n a l y s i s o f g l y c o l - a s h e d b o n e . V a l u e s c a l c u l a t e d p e r d r y b o n e a s s u m i n g a n o r g a n i c p h a s e o f 2 5 p e r c e n t b y

w e i g h t ( 2 3 ) .t No statement c o n c e r n i n g f a t e x t r a c t i o n .§ V a l u e s e x pr e s s e d p e r f a t - f r e e d r y b o n e .

a n d 1 . 7 6 f o r s k u l l , r i b a n d i l i u m , r e s p e c t i v e l y . T h e

N d e t e r m i n e d a p p r o x i m a t e s t h e a m o u n t s o b t a i n e db y o t h e r s ( 5 - 7 ) . T h e f i n d i n g o f a d e c re as e d N

c o n t e n t i n s k u l l i s i n k e e p i n g w i t h t h e o b s e r v a t i o n so f B a k e r , B u t t e r w o r t h a n d L a n g l e y w h o r e p o r t e dt h a t c o mp a c t b o n e h a d l e s s N t h a n c a n c e l l o u s b o n e

( 5 ) . T h e m e a n c h l o r i d e c o n c e n t r a t i o n s o b t a i n e d ,r a n g i n g f r o m 2 8 . 3 t o 4 1 . 1 m E q . , a r e e q u i v a l e n t t o

t h o s e o f E d e l m a n a n d c o - w o r k e r s ( 1 1 ) . C o n -c e r n i n g t h e K c o n t e n t o f human b o n e , t h e o n l yi n f o r m a t i o n f o u n d f o r c o m p a r i s o n w a s i n t h eo l d e r w o r k o f G a b r i e l ( 2 ) , K l e m e n t ( 3 ) , a n d i n

t h e r e c e n t r e p o r t o f P e l l e g r i n o a n d F a r b e r ( 1 3 ) .When t h e v a l u e s o b t a i n e d b y t h e f i r s t t w o a u t h o r sa r e r e c a l c u l a t e d , a s s u m i n g a n o r g a n i c c o n t e n t o f

2 5 p e r c e n t ( 2 3 ) t o e x p r e s s t h e c o n t e n t s p e r k i l o -

g r a m o f d r y b o n e , m e a n c o n c e n t r a t i o n s o f 5 0 a n d

1 3 m E q . a r e o b t a i n e d , r e s p e c t i v e l y . T h e c o n c e n -

t r a t i o n o f 1 0 m E q . f o u n d b y P e l l e g r i n o a n d F a r b e r

i n t i b i a i s i n k e e p i n g w i t h t h e a m o u n t h e r e i n o b -t a i n e d f r o m s k u l l ( 1 3 ) .T h e c o n c e n t r a t i o n s o f Na r e p o r t e d h a v e b e e n

v a r i e d ( T a b l e I I I ) . D i f f e r e n c e s i n s i t e s a n a l y z e da n d i n m e t h o d s e m p l o y e d a r e t h e l i k e l y s o u r c e s f o r

t h e s e v a r i a t i o n s . T h e h i g h e r c o n c e n t r a t i o n o f

s o d i u m i n s k u l l t h a n i n r i b o r i l i u m i s c o n s i s t e n t

w i t h t h e o b s e r v a t i o n s o f E d e l m a n a n d a s s o c i a t e s ,who f o u n d s i m i l a r c h a n g e s i n g r o s s l y n o r m a l b o n e

o b t a i n e d f r o m f i v e a d u l t s ( 1 1 ) . H o w e v e r , t h e

a c t u a l s o d i u m c o n c e n t r a t i o n s o b t a i n e d b y t h e s e

i n v e s t i g a t o r s a r e s o m e w h a t l o w e r t h a n t h e p r e s -

e n t r e s u l t s . From t h e d a t a i n T a b l e I I I i t a p -

p e a r s t h a t t h e s o d i u m c o n c e n t r a t i o n i s h i g h e r i n

c o m p a c t b o n e t h a n i n c a n c e l l o u s b o n e .

T h e d a t a w e r e f u r t h e r e x a m i n e d i n e f f o r t s t o

c l a r i f y t h e r e l a t i v e l o c a t i o n s i n w h o l e b o n e o f

H , 0 , C l , K a n d N a . I f b o n e i s c o n s i d e r e d t o b e

c o m p o s e d o f t w o m a j o r s o l i d p h a s e s , c r y s t a l l i n ea n d o r g a n i c , t h e n t h e C a a n d N c o n c e n t r a t i o n s o f

t h e t o t a l f a t - f r e e s o l i d s s h o u l d s e r v e r e s p e c t i v e l ya s r e f e r e n c e b a s e s f o r t h e s e p h a s e s . T h e r e i s n o

e v i d e n c e t h a t e i t h e r e l e m e n t e x i s t s a s a s i g n i f i c a n t

c o m p o n e n t o f t h e o t h e r p h a s e . I n a g r e e m e n t w i t h

t h i s c o n c e p t i s t h e f a c t t h a t t h e N a n d C a c o n c e n -

t r a t i o n s e x p r e s s e d p e r f a t - f r e e s o l i d s i n t h e c u r r e n t

s t u d y w e r e s i g n i f i c a n t l y i n v e r s e l y r e l a t e d ( p <

0 . 0 2 ) . A c c o r d i n g l y , t h e r e l a t i o n s o f w a t e r , C l ,K a n d Na t o t h e s e r e f e r e n c e s w e r e s t u d i e d .

I n T a b l e IV a r e g i v e n t h e common r e g r e s s i o n so b t a i n e d b y c o m b i n i n g t h e i n d i v i d u a l r e g r e s s i o n s

o f t h e t h r e e b o n e s . C u r r e n t l y i t i s h e l d t h a t a l a r g ea m o u n t o f w a t e r i s a s s o c i a t e d w i t h t h e h y d r a t i o ns h e l l , a n d t h a t C l i o n s p e n e t r a t e t h i s s h e l l ( 2 4 ) .I n t h e p r e s e n t s t u d y i t i s a p p a r e n t t h a t t h e w a t e r

c o n t e n t w a s s i g n i f i c a n t l y r e l a t e d p o s i t i v e l y t o Na n d n e g a t i v e l y t o C a . T h i s f i n d i n g w o u l d b e c o m -

p a t i b l e w i t h t h e c o n c e p t t h a t i n t h e b o n e s s t u d i e d ,t h e w a t e r d e t e r m i n e d a t 1 0 5 ° C . e x i s t e d m a i n l y

a s c e l l u l a r a n d i n t e r s t i t i a l w a t e r r a t h e r t h a n a s w a -

t e r o f t h e h y d r a t i o n s h e l l d e m o n s t r a t e d t o b e

p r e s e n t i n s y n t h e t i c a p a t i t e s a n d v e a l b o n e b y

N e u m a n , T o r i b a r a a n d M u l r y a n ( 2 5 ) .

1 3 5 9

Page 4: jcinvest00346-0039

7/27/2019 jcinvest00346-0039

http://slidepdf.com/reader/full/jcinvest00346-0039 4/5

JAMES W. AGNA, HARVEY C . KNOWLES, J R . , AND GABRIELE ALVERSON

TABLE I V

T h e c o v a r i a n c e r a t i o s a n d s i g n i f i c a n c e s o f common

r e g r e s s i o n s l o p e s ( t h r e e b o n e s ) *

R e g r e s s i o n S l o p e F t

H20-N 1 7 7 1 . 7 8 3 . 6 2 tK-N 1 4 . 7 2 . 6 0 4 . 0 1 tC l - N 1 3 . 6 1 . 1 8 4 . 7 0 tNa-N 0 . 7 6 0 . 7 7 0 . 1 8C03-N - 0 . 1 3 0 . 6 6 4 . 0 3 tH 2 0 - C a - 1 4 7 0 . 4 0 4 . 0 6 tK-Ca - 1 2 . 7 0 . 2 0 4 . 8 1 tC l - C a - 5 . 8 4 1 . 6 6 2 . 1 6 tNa-Ca 6 . 1 7 0 . 4 4 2 . 0 8 tC 0 3 - C a 2 . 3 7 0 . 8 9 2 . 4 1 §

* D e g r e e s o f f r e e d o m i n c l u d e 2 a n d 3 1 f o r t h e F r a t i o ,a n d 3 3 f o r t h e t t e s t .

t S i g n i f i c a n t a t t h e 1 p e r c e n t l e v e l .t S i g n i f i c a n t a t t h e 5 p e r c e n t l e v e l .

§ S i g n i f i c a n t a t t h e 2 p e r c e n t l e v e l .

I n s i m i l a r f a s h i o n , i t i s s h o w n t h a t C l a n d K

w e r e p o s i t i v e l y r e l a t e d t o t h e o r g a n i c p h a s e .H o w e v e r , a s i m i l a r r e l a t i o n b e t w e e n w a t e r , C l , K

a n d N c o u l d a l s o b e o b t a i n e d e v e n i f w a t e r , C 1 a n d

K w e r e p r e d o m i n a n t l y p r e s e n t i n t h e h y d r a t i o n

s h e l l . I n t h i s s i t u a t i o n t h e a g i n g o f c r y s t a l s , w i t h

i n c r e a s e i n s i z e a n d d i s p l a c e m e n t o f w a t e r , w o u l d

o f n e c e s s i t y l e a d t o a n i n c r e a s e d C a t o N r a t i oa n d a d e c r e a s e i n c h l o r i d e a n d K . I n a d d i t i o n ,i t i s a l s o p o s s i b l e t h a t c h a n g e i n p r o p o r t i o n o f t h e

o r g a n i c p h a s e ma y i n s o m e way a f f e c t t h e a m o u n t

o f w a t e r a n d i o n s a s s o c i a t e d w i t h t h e h y d r a t i o ns h e l l a n d c r y s t a l l i n e p h a s e . F i n a l l y , t h e p o s -

s i b i l i t y o f c o u r s e c a n n o t b e o v e r l o o k e d t h a t w a t e r ,C l a n d K a r e l o c a t e d i n b o n e i n s u c h a f a s h i o nt h a t t h e y w o u l d n o t b e r e l a t e d t o e i t h e r o r g a n i c o r

c r y s t a l l i n e p h a s e .R e c e n t l y Neuman a n d Neuman ( 2 4 ) h a v e

q u e s t i o n e d t h e a d v i s a b i l i t y o f a p p l y i n g t h e c a l -

c u l a t i o n s f o r i n t e r s t i t i a l w a t e r a n d e x c e s s s o d i u m

o f b o n e w h i c h H a r r i s o n , D a r r o w a n d Y a n n e t f i r s t

p r o p o s e d ( 2 6 ) . P e r h a p s i n b o n e w h i c h n o t o n l yc o n t a i n s a p a t i t e b u t a n o r g a n i c p h a s e i n t i m a t e l yr e l a t e d t o t h e a p a t i t e , t h e c o n c e p t o f a c h l o r i d e

s p a c e h a s p h y s i o l o g i c m e a n i n g . I n t h e p r e s e n t

s t u d y , t h e mean d e r i v e d c h l o r i d e s p a c e s 8 i n s k u l l

a n d r i b w e r e 2 3 9 a n d 2 9 7 G m . o f w a t e r p e r K g .

o f f a t - f r e e s o l i d s , r e s p e c t i v e l y . T h e s e v a l u e s d o

n o t d i f f e r s i g n i f i c a n t l y f r o m t h e mean w a t e r c o n -

t e n t s , d e t e r m i n e d b y d r y i n g , o f 2 2 9 a n d 3 1 9 G m .

3 D e r i v a t i o n o f t h e c h l o r i d e s p a c e w a s m a d e a s s u m i n g

a p l a s m a C l c o n c e n t r a t i o n o f 1 0 2 m E q . p e r L . , 9 0 p e r

c e n t w a t e r , a n d a D o n n a n f a c t o r o f 0 . 9 5 .

I n c o n t r a s t , t h e m e a n w a t e r c o n t e n t o f i l i u m o f4 4 8 G m . w a s s i g n i f i c a n t l y g r e a t e r t h a n t h a t o f t h e3 4 5 Gm. d e r i v e d f r o m t h e c h l o r i d e s p a c e . T h e s e

c a l c u l a t i o n s w o u l d s u g g e s t t h a t i n r i b a n d s k u l l

t h e w a t e r w a s m a i n l y i n t e r s t i t i a l , w h e r e a s i n i l i u mt h e r e w e r e a d d i t i o n a l c o m p o n e n t s o f c e l l u l a r o r

h y d r a t i o n s h e l l w a t e r .

I t i s o f i n t e r e s t t h a t t h e r a t i o s o f w a t e r , C l a n d

K t o N w e r e l o w e r i n s k u l l t h a n i n r i b a n d i l i u m .I t ma y b e t h a t f a i l u r e t o r e m o v e a l l m a r r o w i n r i b

a n d i l i u m d u r i n g t h e i n i t i a l p r o c e s s i n g a c c o u n t s

i n p a r t f o r t h i s d i s c r e p a n c y . D i r e c t a n a l y s i s o fm a r r o w r e v e a l e d h i g h e r r a t i o s o f w a t e r , C 1 a n d

K t o N t h a n t h o s e f o u n d i n w h o l e b o n e .

A l t h o u g h t h e c o n c e n t r a t i o n s o f Na a n d C a i n

s k u l l w e r e s i g n i f i c a n t l y g r e a t e r t h a n t h o s e o f r i ba n d i l i u m ( T a b l e I ) , t h e r a t i o s o f Na t o C a (m Mt o M) w e r e r e m a r k a b l y c o n s t a n t , b e i n g 4 6 . 4 , 4 6 . 3

a n d 4 7 . 5 , r e s p e c t i v e l y . T h e s e c o n s t a n t r a t i o s s u p -

p o r t t h e c o n c e p t t h a t Na i s p r e d o m i n a n t l y r e l a t e dt o t h e c r y s t a l l i n e p h a s e ( 1 7 ) . H o w e v e r , t h ecommon r e g r e s s i o n o f Na o n C a w a s o n l y p r o b -

a b l y s i g n i f i c a n t ( p < 0 . 0 5 ) . I t i s p o s s i b l e t h a ts u f f i c i e n t Na w a s p r e s e n t i n t h e o r g a n i c p h a s e t oi n v a l i d a t e a m o r e s i g n i f i c a n t r e l a t i o n o f Na t o C a .

SUMMARY

A n a l y s e s o f n o r m a l human s k u l l , r i b a n d i l i u mw e r e m a d e f o r c o n c e n t r a t i o n s o f w a t e r , C a , P .C 0 3 , N , C l , K a n d N a . S k u l l c o n t a i n e d s i g n i f i -c a n t l y g r e a t e r a m o u n t s o f C a , P , C O 3 a n d N a ,

a n d l e s s e r a m o u n t s o f w a t e r , N , C l a n d K t h a n d i di l i u m . T h e c o m p o s i t i o n o f r i b w a s i n t e r m e d i a t eb e t w e e n s k u l l a n d i l i u m . T h e c o n c e n t r a t i o n s o fw a t e r , C l a n d K w e r e r e l a t e d i n q u a n t i t y t o t h ea m o u n t o f o r g a n i c p h a s e p r e s e n t . S o d i u m a p -

p e a r e d t o b e r e l a t e d t o t h e c r y s t a l l i n e p h a s e .

ACKNOWLEDGMENT

T h e a u t h o r s w i s h t o a c k n o w l e d g e h e l p f u l a d v i c e f r o m

D r s . G i l b e r t B . F o r b e s a n d W i l l i a m B e r g s t r o m i n c o n -

n e c t i o n w i t h m e t h od s .

REFERENCES

1 . B e r g s t r o m , W. H . T h e s k e l e t o n a s a n e l e c t r o l y t er e s e r v o i r . M e t a b o l i s m 1 9 5 6 , 5 , 4 3 3 .

2 . G a b r i e l , S . C h e m i s c h e U n t e r s u c h u n g e n u i b e r d i eM i n e r a l s t o f f e d e r K n o c h e n u n d Z a h n e . Z . p h y s i o l . .

C h e m . 1 8 9 4 , 1 8 , 2 5 7 .

1 3 6 0

Page 5: jcinvest00346-0039

7/27/2019 jcinvest00346-0039

http://slidepdf.com/reader/full/jcinvest00346-0039 5/5

THE MINERAL CONTENT OF NORMAL HUMAN BONE

3 . K l e me n t , R . D e r C a r b o n a t g e h a l t d e r A n o r g a n i s c h e n

K n o c h e n s u b s t a n z u n d i h r e S y n t h e s e . B e r . d t s c h .

c h e m . G e s . 1 9 3 6 , 6 9 , 2 2 3 2 .4 . M i t c h e l l , H . H . , H a m i l t o n , T . S . , S t e g g e r d a , F . R . ,

a n d B e a n , H . W. T h e c h e m i c a l c o m p o s i t i o n o f

t h e a d u l t h u m a n b o d y a n d i t s b e a r i n g o n t h e b i o -c h e m i s t r y o f g r o w t h . J . b i o l . C h e m . 1 9 4 5 , 1 5 8 ,6 2 5 .

5 . B a k e r , S . L . , B u t t e r w o r t h , E . C . , a n d L a n g l e y , F . A .

T h e c a l c i u m a n d n i t r o g e n c o n t e n t o f h u m a n b o n e

t i s s u e c l e a n e d b y m i c r o - d i s s e c t i o n . B i o c h e m . J .1 9 4 6 , 4 0 , 3 9 1 .

6 . V o g t , J . H . , a n d T o n s a g e r , A . I n v e s t i g a t i o n s o n t h eb o n e c h e m i s t r y o f m a n . I I . P h o s p h a t a s e , c a l c i u m ,p h o s p h o r u s a n d n i t r o g e n i n t h e s u b s t a n t i a s p o n g i o s ac r i s t a e i l e i . A c t a m e d . s c a n d . 1 9 4 9 , 1 3 5 , 2 3 1 .

7 . R o g e r s , H . J . , W e i d m a n n , S . M . , a n d P a r k i n s o n , A .

S t u d i e s o n t h e s k e l e t a l t i s s u e s . T h e c o l l a g e n c o n -

t e n t o f b o n e s f r o m r a b b i t s , o x e n a n d h u m a n s .

B i o c h e m . J . 1 9 5 2 , 5 0 , 5 3 7 .8 . D a v i e s , R . E . , K o r n b e r g , H . L . , a n d W i l s o n , G . M .

T h e d e t e r m i n a t i o n o f s o d i u m i n b o n e ( a b s t r a c t ) .B i o c h e m . J . 1 9 5 2 , 5 2 , x v .

9 . F o l l i s , R . H . , J r . T h e i n o r g a n i c c o m p o s i t i o n o f t h eh u m a n r i b w i t h a n d w i t h o u t m a r r o w e l e m e n t s .J . b i o l . C h e m . 1 9 5 2 , 1 9 4 , 2 2 3 .

1 0 . F o r b e s , R . M . , C o o p e r , A . R . , a n d M i t c h e l l , H . H .

T h e c o m p o s i t i o n o f t h e a d u l t h u m a n b o d y a s d e -t e r m i n e d b y c h e m i c a l a n a l y s i s . J . b i o l . C h e m .

1 9 5 3 , 2 0 3 , 3 5 9 .1 1 . E d e l m a n , I . S . , J a m e s , A . H . , B a d e n , H . , a n d

M o o r e , F . D . E l e c t r o l y t e c o m p o s i t i o n o f b o n e

a n d t h e p e n e t r a t i o n o f r a d i o s o d i u m a n d d e u t e r i u mo x i d e i n t o d o g a n d h u m a n b o n e . J . d l i n . I n v e s t .1 9 5 4 , 3 3 , 1 2 2 .

1 2 . F o r b e s , G . B . , a n d L e w i s , A . M . T ot a l s od i u m , p o -t a s s i u m a n d c h l o r i d e i n a d u l t m a n . J . d l i n . I n v e s t .1 9 5 6 , 3 5 , 5 9 6 .

1 3 . P e l l e g r i n o , E . D . , a n d F a r b e r , S . J . Human b o n e

e l e c t r o l y t e s i n v a r i o u s d i s e a s e s t a t e s . C l i n . R e s .1 9 5 8 , 6 , 2 5 9 .

1 4 . D e l l a m a g n e , W. J . Some r e c e n t f a c t s a b o u t t h e

p r o p e r t i e s o f t r i c a l c i u m p h o s p h a t e a n d t h e c o m -

p o s i t i o n o f t h e b o n e s a l t . T r a n s . F o u r t h J o s i a h

Macy J r . C o n f . 1 9 5 2 , p . 1 5 4 .1 5 . F o r b e s , G . B . , a n d D ' A m b r u s o , M . D e t e r m i n a t i o n o f

s o d i u m i n b o n e w i t h t h e a i d o f c a t i o n e x c h a n g e

c h r o m a t o g r a p h y . J . b i o l . C h e m . 1 9 5 5 , 2 1 2 , 6 5 5 .1 6 . F i s k e , C . H . , a n d S u b b a r o w , Y . T h e c o l o r i m e t r i cd e t e r m i n a t i o n o f p h o s p h o r u s . J . b i o l . C h e m . 1 9 2 5 ,6 6 , 3 7 5 .

1 7 . S t o l l , W. R . , a n d N e u m a n , W. F . T h e u p t a k e o fs o d i u m a n d p o t a s s i u m i o n s b y h y d r a t e d h y d r o x y -

a p a t i t e . J . A m e r . c h e m . S o c . 1 9 5 6 , 7 8 , 1 5 8 5 .1 8 . W a l l a c e , W. M . , H o l l i d a y , M . , C u s h m a n , M . , a n d

E l k i n t o n , J . R . T h e a p p l i c a t i o n o f t h e i n t e r n a ls t a n d a rd f l am e p h o t o m e t e r t o t h e a n a l y s i s o f b i o -l o g i c m a t e r i a l . J . L a b . d l i n . M e d . 1 9 5 1 , 3 7 , 6 2 1 .

1 9 . P a rk s, T . D . , J o h n s o n , H . O . , a n d L y k k e n , L . E r -

r o r s i n t h e u s e o f a m o d e l 1 8 P e r k i n s - E l m e r f l a m e

p h o t o m e t e r f o r t h e d e t e r m i n a t i o n o f a l k a l i m e t a l s .

A n a l y t . C h e m . 1 9 4 8 , 2 0 , 8 2 2 .2 0 . C h e e k , D . B . , a n d W e s t , C . D . An a p p r a i s a l o f

m e t h o d s o f t i s s u e c h l o r i d e a n a l y s i s : T h e t o t a lc a r c a s s c h l o r i d e , e x c h a n g e a b l e c h l o r i d e , p o t a s s i u m

a n d w a t e r o f t h e r a t . J . d l i n . I n v e s t . 1 9 5 5 , 3 4 , 1 7 4 4 .2 1 . B e r g s t r o m , W. H . T h e r e l a t i o n s h i p o f s o d i u m a n d

p o t a s s i u m t o c a r b o n a t e i n b o n e . J . b i o l . C h e m .

1 9 5 4 , 2 0 6 , 7 1 1 .2 2 . S n e d e c o r , G . W. S t a t i s t i c a l M e t h o d s , f i f t h e d . A m e s ,

T h e I o w a S t a t e C o l l e g e P r e s s , 1 9 5 6 .2 3 . S t a c k , M . V . T h e c h e m i c a l n a t u r e o f t h e o r g a n i c

m a t r i x o f b o n e , d e n t i n , a n d e n a m e l . A n n . N . Y .

A c a d . S c i . 1 9 5 5 , 6 0 , 5 8 5 .

2 4 . N e u m a n , W. F . , a n d N e u m a n , M . W. E m e r g i n g c o n -c e p t s o f t h e s t r u c t u r e a n d m e t a b o l i c f u n c t i o n s o fb o n e . A m e r . J . M e d . 1 9 5 7 , 2 2 , 1 2 3 .

2 5 . N e u m a n , W. F . , T o r i b a r a , T . Y . , a n d M u l r y a n , B . J .

T h e s u r f a c e c h e m i s t r y o f b o n e . V I I . T h e h y d r a -

t i o n s h e l l . J . A m e r . c h e m . S o c . 1 9 5 3 , 7 5 , 4 2 3 9 .2 6 . H a r r i s o n , H . E . , D a r r o w , D . C . , a n d Y a n n e t , H . T h e

t o t a l e l e c t r o l y t e c o n t e n t o f a n i m a l s a n d i t s p r o b -

a b l e r e l a t i o n t o t h e d i s t r i b u t i o n o f b o d y w a t e r .

J . b i o l . C h e m . 1 9 3 6 , 1 1 3 , 5 1 5 .

1 3 6 1