Effect of colchicine on steroid secretion from rat adrenal gland.

To determine the influence of colchicine on adrenocortical function in vivo, we gave significant amounts subcutaneously to rats and observed the distribution to the anterior pituitary and adrenal glands. Corticosteroids in the serum and adrenal gland were increased remarkably by the administration of colchicine in a dose-dependent manner. Maximum elevation was achieved around 2.5 hours after the injection and continued for at least 4 hours. Maximum levels produced by the injection of 0.1 U/rat of adrenocorticotropic hormone, the latter producing temporary increases in corticosteroids in the serum and adrenal gland. A significant augmentation of corticosteroids in the serum and adrenal gland resulted when colchicine was administered 60 minutes prior to the injection of adrenocorticotropic hormone. The pattern of intracellular distribution of corticosteroids in the adrenal glands of rats given colchicine was the same as that seen in rats given adrenocorticotropic hormone. In the in vitro experiment, only high concentrations of colchicine such as 10(-3) M added to the incubation system of the adrenal quarters suppressed the release of corticosteroids from the adrenal gland. Thus, the continuous stimulation of the synthesis and secretion of adrenocortical hormone seen with the administration of colchicine may explain why this drug is effective in the treatment of gouty arthritis.