In Vivo Stimulation of Insulin Secretion by Guanidine Derivatives in the Rat

Abstract

The comparative effects of acute intravenous injection of guanidine and its derivatives arginine, guanidinoacetic acid, guanidinopropionic acid, guanidinobutyric acid and guanidinobutyramide on plasma insulin and blood glucose have been examined in the conscious rat. Guanidine chloride, 0.5 and 1 mmol/kg, caused an immediate increase (up to 145 µU/ml) in plasma insulin one minute after injection, which persisted for 20 mins with the higher dose; 0.1 mmol/kg was without effect. In contrast, guanidinopropionic acid and arginine hydrochloride caused a significant increase in plasma insulin at 0.1 mmol/kg. Guanidinobutyramide had a small effect at 0.1 and 0.5 mmol/kg while guanidinobutyric acid was effective only at 0.5 mmol/ kg. Atropine caused a 45% inhibition of guanidine stimulated insulin secretion but did not influence the potent effect of the guanidine diuretic, amiloride. Blood glucose was not affected, compared with saline injected control animals, by any of the guanidines at the doses tested.

Key words

Guanidine Chloride - Guanidinoacetic Acid - Guanidino-propionic Acid - Guanidinobutyric Acid - Guanidinobutyramide - Amiloride Hydrochloride - Atropine - Plasma Insulin - Blood Glucose - Conscious Rat - Diuretic - Atropine