Submitted on September 26, 2008
Revised on January 30, 2009
Accepted on January 30, 2009
INCREASED EXPRESSION OF RECEPTORS FOR OREXIGENIC FACTORS IN NODOSE GANGLION OF DIET-INDUCED OBESE RATS
Gabriel Paulino1, Claire De La Serre1, Trina Knotts2, Pieter J. Oort1, John Newman1, Sean Adams1, and Helen E. Raybould3*
1 University of California, Davis
2 University of California
3 School of Veterinary Medicine, University of California
* To whom correspondence should be addressed. E-mail: heraybould{at}ucdavis.edu.
The vagal afferent pathway is important in short-term regulation of food intake and decreased activation of this neural pathway with long-term ingestion of a high fat diet may contribute to hyperphagic weight gain. We tested the hypothesis that expression of genes encoding receptors for orexigenic factors in vagal afferent neurons are increased by long-term ingestion of a high fat diet, thus supporting orexigenic signals from the gut. Obesity prone (DIO P) rats fed a high fat diet showed increased body weight and hyperleptinemia compared to low fat fed controls and high fat fed diet-induced obese resistant (DIO R) rats. Expression of the type I cannabinoid receptor and growth hormone secretagogue receptor in the nodose ganglia was increased in DIO P compared with low fat fed or DIO-R rats. Shifts in the balance between orexigenic and anorexigenic signals within the vagal afferent pathway may influence food intake and body weight gain induced by high fat diets.
