Insulin secretion

Glucagon (19-29), from 0.1 pM to 1 nM, exerts a potent negative inotropic action. The most striking observation is a 45% increase in the amplitude of cell contractility elicited by the combination of 30 nM glucagon with 1 nM Glucagon (19-29).

Glucagon (19-29), also named Miniglucagon, is the COOH-terminal (19-29) fragment processed from glucagon. Glucagon (19-29) dose-dependently inhibits insulin secretion stimulated by 8.3 M glucose, with no change in the perfusion flow rate. A concentration of 1 nM Glucagon (19-29) has a significant inhibitory effect on a 1 nM glucagon-like peptide 1 (7-36) amide–potentiated insulin secretion. Glucagon (19-29) is a highly potent and efficient inhibitor of insulin release by closing, via hyperpolarization, voltage-dependent Ca ²⁺ channels linked to a pathway involving a pertussis toxin-sensitive G protein.