Gastric Inhibitory Polypeptide Release into the Portal Vein in Response to Intraduodenal Glucose Loads in Anesthetized Rats

Abstract

Gastric inhibitory polypeptide (GIP) release into the portal vein in response to duodenal instillation of glucose in doses of 0.695, 1.39, 2.78 and 5.56 mmol/kg body weight was studied in an acute condition in male Wistar rats. A rapid, dose-dependent, and significant rise in portal vein plasma GIP was found in response to increasing duodenal glucose loads, which could be described by Michaelis-Menten kinetics. It is suggested that the glucose-induced GIP release into the portal vein mainly is effected first after glucose has gained access inside the mucosal cells.

Key-words:

• Duodenal glucose
• gastric inhibitory polypeptide (GIP)
• Michaelis-Menten kinetics
• portal vein plasma
• radioimmunoassay
• rats