Stimulation of insulin secretion by GAA
Insulin secretion was measured in the isolated perfused rat pancreas in response to guanidinoacetic acid and other guanidine derivatives. Guanidinoacetic acid appears to be more potent than arginine, creatine and guanidine in stimulating insulin secretion. Parasympathetic mediation is unlikely because insulin secretion in response to these compounds is no inhibited by atropine. The guanidino group maybe an important factor in arginine-stimulated insulin release. Glycine, which does not have aguanidino group, also increases insulin levels. It is possible that, in addition, arginine and glycine may release insulin by being converted to guanidinoacetic acid.
Alsever RN, Georg RH, Sussman KE. Stimulation of insulin secretion by guanidinoacetic acid and other guanidine derivatives. Endocrinology. 1970 Feb;86(2):332-6. doi: 10.1210/endo-86-2-332. PMID: 4902876.