Two human glucagon-like peptides, GLP-1 and GLP-2, which are coencoded with pancreatic glucagon in the preproglucagon gene, do not significantly inhibit [125I]monoiodoglucagon binding to rat liver and brain membranes and do not activate adenylate cyclase in liver plasma membranes. Nevertheless, GLP-1 and GLP-2 were each found to be potent stimulators of both rat hypothalamic and pituitary adenylate cyclase. Only 30-50 pM concentrations of each peptide elicited half-maximal adenylate cyclase stimulation. Our data suggest that GLP-1 and GLP-2 may be neurotransmitters and/or neuroendocrine effectors, which would account for their high degree of sequence conservation through vertebrate evolution. © 1984.
Hoosein, N. M., & Gurd, R. S. (1984). Human glucagon-like peptides 1 and 2 activate rat brain adenylate cyclase. FEBS Letters, 178(1), 83–86. https://doi.org/10.1016/0014-5793(84)81245-4