The metabolic and clinical effects of pituitary adrenocorticotropic hormone (ACTH) in spontaneous hypoglycemosis

The effects of ACTH on the fasting blood sugar level and glucose tolerance test; on the potassium and inorganic phosphorus content of the serum; on the nitrogen, phosphorus, chloride, sodium and potassium balances; on the urinary excretion of uric acid, creatinine and adrenal corticosteroids and on the blood eosinophil counts were determined in five young children with non-Addisonian (familial) hypoglycemia. The type of response to ACTH was similar in all respects of the normal adult. However, under the conditions of our experiment, instead of producing a transient state of diabetes mellitus, as it does in the normal subject, the ACTH appeared merely to reverse the hypoglycemic tendency, with return of the fasting blood sugar levels and the glucose tolerance curve to normal. While the eosinophil count returned to normal promptly upon withdrawal of ACTH, the blood sugar remained above the threshold for hypoglycemic reactions for at least 10 days without ACTH in the most severe case in the series. (Figure 2) The same tendency was seen in the other four cases as well. In all instances, however, the original degree of hypoglycemia recurred at varying periods following withdrawal of the ACTH. After this had occurred in B.G., the hormone was again given intensively for two days, again raising the blood sugar to normal values. Administration of between 10 and 18 mg. of ACTH in one dose every forty-eight hours since that time (five months) has served to maintain this one-year-old patient in an essentially non-hypoglycemic state. Results of the study suggest, therefore, that ACTH may prove to be as effective in the control of chronic non-Addisonian hypoglycemosis as insulin is in the control of diabetes mellitus.

The action of glutamic acid in hypoglycaemic coma

The loss of consciousness in hypoglycaemia is generally regarded as a direct consequence of the fact that the brain cells are being increasingly deprived of glucose, their principal fuel. The prompt relief of symptoms by glucose administration led to a number of investigations on the effect of other substrates known to sustain the respiration of surviving brain slicesin vitro.Amongst these are various mono- and disaccharides, and such acids as lactic, pyruvic, succinic or glutamic acid which may be formed from glucose in the course of its metabolism. It appeared, however, that, in contrast to theirin vitroaction, most of these substances, including glutamic acid, were unable to relieve the symptoms of hypoglycaemia in eviscerated or hepatectomized animals (Bollmann and Mann, 1931; Maddock, Hawkins and Holmes, 1939). Similarly, lactic and pyruvic acids were found to have no effect on the oxygen consumption of the brain or the comatose state of hypoglycaemic patients undergoing insulin shock therapy (Wortis and Goldfarb, 1940; Goldfarb and Wort is, 1941). It has been shown for several substrates, including glutamic acid, that their rate of diffusion from the blood stream into brain tissue was markedly slower than that of glucose, and that therefore the concentration necessary for the maintenance of nervous function was not reached (Klein, Hurwitz and Olsen, 1946; Klein and Olsen, 1947). In harmony with this are the observations of Fried berg and Greenberg (1947), and of Waelsch, Schwerin and Bessman (1949) that intravenously injected glutamic acid is not taken up by brain tissue. The differences between thein vitroandin vivoresults seemed to be adequately explained by these experiments.