THE INFLUENCE OF ACTH ON THE SODIUM AND POTASSIUM CONCENTRATION OF HUMAN MIXED SALIVA

Abstract

Specimens of unstimulated mixed saliva were collected from 4 patients before each meal and at bedtime for several days, before, during and after ACTH therapy. The concns. of Na and K in the saliva were measured by flame photometry. The urinary 17-ketosteroid excretion and counts of circulating eosinophils were also detd. daily in 1 of the patients. AC.TH reduced the Na concn. of the saliva while increasing that of K. Thus, ACTH decreased the Na/K ratio of saliva in 15 out of 16 expts. Simultaneously, the urinary 17-ketost3roid excretion increased and the circulating eosinophil count decreased. Hence, the ACTH-induced changes in the Na/K ratio of saliva was probably mediated via the adrenal cortex. The Na/K ratio was higher in unstimulated saliva secreted before breakfast than in that secreted at the other times of the day, throughout the entire period of investigation. This diurnal rhythm was probably due to a lower output of endogenous ACTH before breakfast. It was not due to any refractoriness of the Na/K ratio of saliva collected before breakfast because its response to admd. ACTH was as marked as that of the Na/K ratio of specimens collected at the other times. The Na and K concn. of saliva, of sweat and the amts. of Na and K in the urine responded similarly to ACTH. The day-to-day variation in the Na and-K concn. of unstimulated saliva collected at the same time of day was low, even though the subjects were on an unrestricted intake of Na and K. These studies on saliva are technically simpler than the comparable studies on urine or sweat.