High-fat diet increases ghrelin-expressing cells in stomach, contributing to obesity.

Abstract Objectives Mechanisms of high-fat diet (HFD)–induced obesity may involve ghrelin, an orexigenic and adipogenic hormone secreted by the stomach. Previous studies showed that obese subjects may display higher numbers of ghrelin-producing cells and increased affinity of plasma immunoglobulins (Ig) for ghrelin, protecting it from degradation. The aim of this study was to determine if a HFD in mice would increase the number of ghrelin-expressing cells and affinity of ghrelin-reactive IgG. Methods Obesity in mice was induced by consumption of a 13-wk HFD. The number of preproghrelin mRNA-expressing cells in the stomach was analyzed by in situ hybridization and compared with chow-fed, nonobese controls and with genetically obese ob/ob mice. Affinity of ghrelin-reactive IgG was analyzed using surface plasmon resonance. Plasma levels of ghrelin and des-acyl ghrelin were measured. Results HFD resulted in 30% of body fat content versus only 8% in controls ( P P ob/ob mice, having a 41% ( P P Conclusion Results from the present study showed that HFD in mice induces obesogenic changes, including increased numbers of ghrelin precursor-expressing cells and increased affinity of ghrelin-reactive IgG. Such changes may contribute to the mechanisms of HFD-induced obesity.