Distinct brain regions mediate regulation of food intake in response to GIPR agonism or antagonism.

Preclinical animal study using region-specific gene knockout in mice

“The study employs region-specific knockout of the glucose-dependent insulinotropic polypeptide receptor (GIPR) in either the area postrema or hypothalamus of mice to determine how GIPR agonism and antagonism regulate food intake and body weight via distinct brain regions.”

Mice with targeted knockout of Gipr in the area postrema or hypothalamus

“We knock out Gipr in either the area postrema (AP) or hypothalamus of mice (GiprAP-KO and Giprhypo-KO, respectively) and compare body weight and food intake responses to GIPR agonists and antagonists, alone and in combination with the GLP-1R agonist liraglutide.”

GIPR in the hypothalamus mediates the synergistic weight loss effects of GIPR antagonists combined with GLP-1R agonists

“Giprhypo-KO also abolishes the synergistic effect of a GIPR antagonist when combined with liraglutide—an effect that is not mediated by nucleus tractus solitarius preproglucagon neurons.”

The study used relatively small group sizes, though results were reproducible

“While it may be argued that our study used relatively small group sizes, the results were significant and reproducible, consistent with the large effect sizes and low variability of our experimental paradigms.”