Effect of verapamil and diltiazem on basal and acth-induced corticosterone secretion in the rat

ABSTRACT

It has been proposed that calcium plays an important role in endocrine reactions such as hormone biosynthesis, release, secretion and action on tarhet organs. The aim of this study was to evaluate the effects of the ca++ channel blockers [verapamil and diltiazem] on basal and ACTH induced corticosterone secretion in the rat. ACTH produced an increase in the plama level of both corticosterone and glucose with peak effect occurring one and two hours respectively. In this respect, administration of verapamil [20 mg kg-1; p.o.] and diltiazem 20 mg kg-1;p.o.] to rats for 8 days produced nonisgnificant change in both basal or stimulated corticosterone levels after challenge doses of ACTH [4 units kg-1 s.c.]. similarly the fasting plasma glucose level was not significantly modified by neither verapamil nor diltiazem as compared with the control group. These results suggest that the ca++ channels blocked by verapamil and diltiazem may not be directly involved in steroidogenesis, at least in the rat. Further studies may however be needed to fully characterize the role of the ca++ channels and drugs of different chemical groups which modulate such channels