Secretin potentiates cholinergically induced glucagon secretion in the mouse

Area of Science:

• Endocrinology
• Gastrointestinal Physiology
• Neuroendocrinology

Background:

• Cholinergic activation stimulates glucagon secretion.
• Vasoactive intestinal polypeptide (VIP) and gastric inhibitory polypeptide (GIP) potentiate this effect.
• Secretin shares structural similarities with VIP and GIP.

Purpose of the Study:

• To investigate secretin's effect on basal and cholinergically induced glucagon secretion in mice.
• To determine if secretin modulates glucagon secretion similarly to VIP and GIP.

Main Methods:

• Intravenous injection of secretin in mice across a dose range (0.53–17 nmol kg-1).
• Measurement of plasma glucagon and glucose levels at 2, 6, and 10 minutes post-injection.
• Administration of the cholinergic agonist carbachol, alone and in combination with secretin.

Main Results:

• Secretin did not affect basal glucagon concentrations.
• Carbachol significantly increased plasma glucagon levels.
• Secretin potentiated carbachol-induced glucagon secretion by 70%, leading to elevated plasma glucose levels.

Conclusions:

• Secretin potentiates cholinergic stimulation of glucagon secretion in mice.
• This potentiation results in increased plasma glucose levels.
• Secretin plays a role in modulating glucose homeostasis via glucagon secretion.