Fatty Acid Preference is Differentially Mediated by Nutritional Status and Lingual CD36 in Obesity‐Prone and Resistant Rats

Abstract

Fatty acid receptors on the tongue mediate oral sensing of fat/fatty acids and are proposed mechanisms contributing to the susceptibility to obesity. The first goal of the current experiments was to investigate the role of nutritional status on lingual CD36 expression in obesity‐prone Osborne‐Mendel (OM) and obesity‐resistant S5B/Pl (S5B) rats. The second goal was to assess the effects of nutritional status on linoleic acid (LA) preference in these rat models. In Exp. 1A, lingual CD36 protein expression was measured in OM and S5B rats fed a high fat diet (HFD). In Exp.1B, OM and S5B rats were fed a HFD and the preference threshold for increasing concentrations of LA was evaluated. In Exp. 2A, lingual CD36 mRNA expression was measured in OM and S5B rats fed a chow diet and fasted overnight. In Exp. 2B, the preference threshold for increasing concentrations of LA was determined following an overnight fast. In Exp. 3, the effect of lingual CD36 siRNA application on LA preference following an overnight fast in OM and S5B rats was assessed. Consumption of HFD decreased lingual CD36 protein levels and LA preference threshold in S5B rats, compared to OM rats. Following an overnight fast, lingual CD36 mRNA levels were elevated in S5B rats, compared to OM rats. LA preference threshold was not differentially altered in fasted OM and S5B rats. Application of CD36 siRNA decreased LA preference following an overnight fast in S5B rats, compared to OM rats. These data suggest that nutritional status leads to more pronounced alterations in lingual CD36 expression and LA preference in resistant S5B rats, compared to prone OM rats and supports a role for orosensory fat detection in the susceptibility to developing obesity. LSUHSC to SDP