EVIDENCE FOR STIMULATION OF INSULIN SECRETION BY GROWTH HORMONE IN THE RAT¹

AN EFFECT OF CORTICOTROPIN ON UREA FORMATION IN ADRENALECTOMIZEDNEPHRECTOMIZED RATS1

“…Milligram for milligram ACTH is at least as active if not more active than growth hormone, although as emphasized in previous papers, the doses of ACTH used are huge when expressed in units. The response of ACTH to various inactivation and reactivation procedures corresponds with what we have reported for other adrenal and extra-adrenal actions of ACTH (5,6,7,8). In view of the dose relationships and the fact that growth hormone was not clearly inactivated by H 2 O 2 treatment whereas ACTH was, one can definitely rule out the possibility that the response to the ACTH samples used was due to contamination with growth hormone.…”

“…Oxycel ACTH boiled in 0.1N alkali lost activity; when subjected to the more gentle alkali treat- . We have previously found in other studies that cysteine reactivation may not be complete and hence that it is necessary to use maximal rather than minimal doses to demonstrate the phenomenon (5,7,8). In contrast to the results with ACTH, treatment of growth hormone with H 2 O 2 did not lead to clearcut inactivation.…”

“…We have previously reported that the extra-adrenal metabolic effects of ACTH are lost in parallel with its adrenal stimulating activity when the hormone is boiled in 0.1N NaOH or oxidized with H 2 O 2 (5,6,7,8). In the latter case activity may be restored in part at least by treatment of the oxidized hormone with cysteine.…”

“…In view of the recent claims from this laboratory and elsewhere that highly purified corticotropin exerts a number of metabolic actions in adrenalectomized animals which simulate those of growth hormone (3,4,5,6,7,8,9) an investigation of the influence of corticotropin on nitrogen metabolism was initiated using a modification of Russell's technique. At our instigation Russell has already tested a sample of oxycel ACTH and has reported that it does indeed have a growth hormone-like effect in the nephrectomized rat (10).…”

Acute Suppressive Effect of Human Growth Hormone on Basal Insulin Secretion in Man

“…inducing decreases in blood glucose and serum free fatty acid levels (Westermeyer Sc Raben 1954;Engel et al 1958;Zahnd et al 1960;Daughaday Sc Kipnis 1966;Frohman et al 1967). We demonstrated recently that, shortly after an iv infusion of pharmacological amounts of human GH, the glucose tolerance and the insulin response to glucose were lowered in normal man (Cerasi et al 1972).…”