Metabolic effects of ACTH in the tammar wallaby, Macropus eugenii: The role of the adrenal medulla

Abstract

Infusion of ACTH into bilaterally adrenalectomised tammar wallabies ( Macropus eugenii) has no effect on blood glucose levels, whereas infusion of cortisol or adrenaline results in increases in blood glucose concentrations. Infusion of cortisol into intact tammars does not change the rate of turnover of blood glucose, while during infusion of ACTH or adrenaline, blood glucose turnover increases. These findings, together with those previously reported (Cooley and Janssens, 1977), are consistent with the hypothesis that adrenaline is involved in early metabolic responses to ACTH administration in the tammar. Bilaterally adrenalectomised tammars can be maintained for at least 2 months with daily injections of 0.2 mg/kg deoxycorticosterone. Tammars die within 48 hr of cessation of hormone injection even if they are offered saline to drink.