Behavioral responses to orexin, orexin receptor gene expression, and spontaneous physical activity contribute to individual sensitivity to obesity

Claudio E. Perez-Leighton, Kelsey Boland, Jennifer A. Teske, Charles Billington, Catherine M. Kotz

Producción científica: Contribución a una revistaArtículorevisión exhaustiva

50 Citas (Scopus)

Resumen

There is significant variability in diet-induced obesity (DIO) among humans and rodents, which has been associated with differences in intrinsic spontaneous physical activity (SPA). The orexin neuropeptides positively modulate SPA through multiple brain sites, but the effects of DIO on orexin's activity are not well understood. In this study, we tested the hypothesis that DIO sensitivity is mediated by decreased SPA and changes in the function of the orexins. As a DIO model, we used male Sprague-Dawley rats fed a high-fat (HF; 45% kcal from fat) or a low-fat (LF; 10% kcal from fat) diet for 10 wk. We measured SPA before and after HF or LF feeding and expression of orexin receptors by real-time PCR after dietary treatments. We tested DIO effects on orexin signaling by measuring SPA after injection of orexin A in the rostral lateral hypothalamus (RLH) before and after 10 wk of HF feeding. Finally, we tested whether daily orexin A RLH injections prevent DIO caused by HF feeding. Our results show that resistance to DIO is associated with an increase in SPA, SPA after injection of orexin A in RLH, and orexin receptor expression in sites that mediate orexin's effect on SPA, including RLH. We show that daily injections of orexin peptide in RLH prevent DIO without altering food intake. We estimate that the energetic cost of SPA after orexin A RLH injection accounts for approximately 61% of the extra caloric intake associated with HF intake, suggesting additional effects of orexins. In summary, our results suggest that variability in DIO sensitivity is mediated through adaptations in the activity of the orexin peptides and their receptors.

Idioma originalInglés
Páginas (desde-hasta)E865-E874
PublicaciónAmerican Journal of Physiology - Endocrinology and Metabolism
Volumen303
N.º7
DOI
EstadoPublicada - 1 oct. 2012

Áreas temáticas de ASJC Scopus

  • Medicina General

Huella

Profundice en los temas de investigación de 'Behavioral responses to orexin, orexin receptor gene expression, and spontaneous physical activity contribute to individual sensitivity to obesity'. En conjunto forman una huella única.

Citar esto