The experimental ischemic shock induced by removing tourniquets in rats, were studied. Durin 164 hours, the variations of the values of hematocrit and of muscle and plasma dehydrogenase lactate activity were followed up; the modifications of these variations after pharmacological high doses of dexamethasone phosphate, hydrocortisone hemisuccinate and aprotinine administered intravenously, were evaluated. The best action was noted after dexamethasone phosphate treatment.