MONDAY, March 16 (HealthDay News) -- Endogenous hindbrain glucagon-like-peptide-1 receptor (GLP-1R) activation contributes to the control of food intake by mediating gastric satiation signaling, according to the results of an animal study published online ahead of print March 5 in Endocrinology.
Matthew R. Hayes, Ph.D., of the University of Pennsylvania in Philadelphia, and colleagues studied the effects of the selective GLP-1 receptor antagonist Exendin-(9-39) (Ex-9; American Peptide Inc., Sunnyvale, Calif.) in a series of experiments with adult male Sprague Dawley rats.
The investigators found that food intake increased with GLP-1R agonist delivered to rats deprived of food overnight after ingesting the Ensure diet. Direct medial nucleus tractus solitarius injection of a subthreshold dose of Ex-9 also increased food intake. The researchers then performed two experiments in overnight-fasted rats -- one in which rats were given Ensure intraduodenally and another in which rats' stomachs were distended for 15 minutes prior to fourth intracerebroventricular Ex-9. They found that the GLP-1R blockade did not significantly affect the intake suppression by duodenal nutrient infusion but that the feeding suppression that followed gastric distension was significantly attenuated by fourth intracerebroventricular Ex-9.
"We conclude that endogenous nucleus tractus solitarius GLP-1R activation driven by gastric satiation signals contributes to the control of normal feeding," the authors write.
