Conditioning by Cortisol for the Production of Acute Massive Myocardial Necroses During Neuromuscular Exertion

PREVIOUS observations 1 have shown that rats, pretreated with 2-methyl-9a-chlorocortisol (Me-Cl-COL) and an excess of dietary phosphate, develop massive myocardial necroses within a few hours following exposure to various stressor agents. Me-Cl-COL is an artificial synthetic steroid which does not occur in nature; it possesses rather unusual pharmacologic properties in that it is not only extraordinarily active as a mineralocorticoid, but it also exhibits some glucocorticoid effects. I t was therefore important to determine: (1) whether cortisol* (a predominantly glucocorticoid substance known to be produced in excess during stress in man) could take the place of Me-Cl-COL in conditioning the rat for the production of acute myoeardial necroses by neuromuscular exertion and (2) whether desoxycorticosterone (a virtually pure mineralocorticoid) exhibits similar effects.