Abstract
The effect of hormonal stimulation upon the interrenal (adrenocortical) cells of the male bullfrog (Rana catesbeiana) was investigated histological -ly. A single administration of l0 mg ACTH to the November frogs was followed by a rapid transformation of the lipid cells into the acidophilic summer cells, and the cortex was entirely occupied by the reserved acidophilic summer cells only within 30 min. Within 6 hr. the loss of lipid cells was recovered to the normal level. The adrenals of normal breeding frogs were full of particularly enlarged summer cells. When the March or April frogs received a single injection of 3 repeated injections of the same dose of ACTH, and even when they were unilaterally nephro-adrenalectomized, both cortical cells showed no significant change. Thus, the seasonal variation during the breeding period is too intrinsic to be modified by the addition of exogenous or endogenous ACTH. When the November frogs were administered singly with 1 mg/kg. Metopirone, the hypertrophy of cortical cells showing the prolonged inhibition of steroidogenesis was not detectable. However, when the November frogs which had been pretreated with Metopirone were injected singly with lOmg of ACTH, the effect of ACTH upon the cellular transformation was arrested. The May frogs were injected with 2 or 4 of testosterone propionate for 9 or 13 days most of the summer cells were regressed chronically, whereas the lipid cells were supplemented. From these results, it has been reinforced that the acidophilic summer cell may be originated from the lipid cell.