Micron and Microscopica Ada. Vol. 22, No. 3, p. 31)2, 1991. 1)739-6260/91$31111 +0.00Printed in Great Britain. Pergamon Pressplc

A MUSCLE CRUSH INJURY MODEL IN DOGS AND RATS:

HISTOLOGY AND ULTRASTRUCTURE

R.Coleman, I.Rubinstein, H.Ben—Ari, M.Silbermann & O.S.Better

Rappaport Family Institute & The Bruce Rappaport Faculty of Medicine

Technion—Israel Institute of Technology, Haifa 31096, Israel

Crush Syndrome (CS) is a common devastating sequel following catastrophes.

The purpose of the present study was to develop a reproducible animal model

to study local and systemic effects of crush injury. Such a model could

conceivably help in devising strategies for improving management of CS in man.

In dogs, local internal pressure (140mm Hg [vs normal 0±4mmHg]) was induced

in hindlimbs by means of injection of autologous plasma to the anterior tibialis

compartment for 4 hours. After 7 days the anterior tibiallis muscle showed

severe damage as seen in histological and TEM studies. Myocytes were swollen

and showed a centralization and aggregation of nuclei, which were enlarged

with extremely prominent nucleoli. The sarcomeres were clearly damaged and

disrupted with myofilament loss. The connective tissue showed large numbers

of satellite cells and macrophages.

In Sprague—Dawley rats a novel apparatus was used to apply local controlled

external pressure (4.25 atmospheres) to the hind limbs for 1 and 2 hours. The

anterior tibialis muscle was removed 4 days after the pressure injury.

Histological and ultrastructural degenerative changes seen in the rat were

similar to those found in the compartmentalized pressure injury in the dog.

In addition, many of the damaged and degenerating myofibers showed large numbers

of enormous lipid droplets and lysosome—like bodies. The adjacent macrophages

also possessed abundant cytoplasmic lipid inclusions.

The rat external pressure model of crush injury is being developed owing to

the advantages it permits over the dog model (cost, ease of handling and

reproducibility).

This study was supported in part by a grant from the Israel

Ministry of Defence (Technion 185-108)

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