CORTICOSTEROIDS AND TRANSAMINASE ACTIVITY: THE SPECIFICITY OF THE GLUT AMI C-PYRU VIC TRANSAMINASE RESPONSE1

Marked increases (2 to 5-fold) in glutamic-pyruvic transaminasc activity were observed in the livers of rats given cortisol, cortisone or several other corticosteroids subcutaneously for 4 consecutive days. Two biologically inert analogues of cortisol, 11-epicortisol and 9α-methoxycortisol acetate, were essentially inactive in this respect. Treatment with cortisol increased the activity of this transaminase markedly in thymus, liver and pancreas, to a lesser extent in kidney, and to no significant degree in spleen, muscle, heart, diaphragm, adrenal, testis and lung. The administration of adrenocorticotrophic hormone doubled the activity of glutamic-pyruvic transaminase in liver. Hypophysectomy increased the endogenous level of the transaminase in liver. Injection of cortisol elicited an increase in the activity of this transaminase in the liver of adrenalectomized or hypophysectomized rats which was similar to that observed in intact animals. Growth hormone, testosterone and insulin did not significantly affect liver glutamic-pyruvic transaminase activity nor did they impair the response of this enzyme when given in combination with cortisol.