EFFECTS OF CALCIUM ON THE POTASSIUM AND SODIUM CONTENT OF RAT ADRENAL GLANDS, ON THE STIMULATION OF STEROID PRODUCTION BY ADENOSINE 3′,5′-MONOPHOSPHATE, AND ON THE RESPONSE OF THE ADRENAL TO SHORT CONTACT WITH ACTH

Abstract

The potassium content of incubated rat adrenal tissue is significantly higher when calcium is present in the incubation medium than when it is absent. The effect of calcium on the sodium content of the adrenal depends upon the presence of ACTH; increased values are obtained with calcium in the presence of ACTH, decreased values in its absence. There is no correlation between the potassium or sodium content of the tissue and its ability to respond to ACTH. Adenosine 3′,5′-monophosphate triples the steroid output of incubated adrenal glands in the absence of both glucose and calcium. Addition of calcium further doubles this response while glucose has only a small effect. The stimulation of steroid production following short contact with ACTH does not depend upon the presence of calcium or glucose in the medium during the time the glands are exposed to the hormone. The results suggest that some step between contact of the tissue with ACTH and the elaboration of adenosine 3′,5′-monophosphate requires the presence of glucose and not necessarily calcium and that a reaction in the sequence between elaboration of the nucleotide and steroid production requires the presence of calcium, but not of glucose.