Douglas Braymer H, Zachary Hannah, Schreiber Allyson L, Primeaux Stefany D
Pennington Biomedical Research Center, Baton Rouge, LA 70808, United States.
Department of Physiology, LSU Health Sciences Center, New Orleans, LA 70112, United States.
Physiol Behav. 2017 May 15;174:120-127. doi: 10.1016/j.physbeh.2017.03.015. Epub 2017 Mar 14.
Lingual fatty acid receptors (i.e. CD36) mediate the orosensory perception of fat/fatty acids and may contribute to the susceptibility to develop obesity. The current study tested the hypothesis that fat/fatty acid preference in obesity-prone (OP, Osborne-Mendel) and obesity-resistant (OR, S5B/Pl) rats is mediated by nutritional status and lingual CD36. To determine if nutritional status affected linoleic acid (LA) preference in OP and OR rats, rats were either fasted overnight or fed a high fat diet (60% kcal from fat). In OR rats, fasting increased the preference for higher concentrations of LA (1.0%), while consumption of a high fat diet decreased LA preference. In OP rats, fasting increased the preference for lower concentrations of LA (0.25%), however high fat diet consumption did not alter LA preference. To determine if lingual CD36 mediated the effects of an overnight fast on LA preference, the expression of lingual CD36 mRNA was assessed and the effect of lingual application of CD36 siRNA on LA preference was determined. Fasting increased lingual CD36 mRNA expression in OR rats, but failed to alter lingual CD36 mRNA in OP rats. Following an overnight fast, application of lingual CD36 siRNA led to a decrease in LA preference in OR, but not OP rats. Lingual application of CD36 siRNA was also used to determine if lingual CD36 mediated the intake and preference for a high fat diet in OP and OR rats. CD36 siRNA decreased the preference and intake of high fat diet in OR rats, but not OP rats. The results from this study suggest that the dysregulation of lingual CD36 in OP rats is a potential factor leading to increased fat intake and fat preference and an enhanced susceptibility to develop obesity.
舌部脂肪酸受体（即CD36）介导对脂肪/脂肪酸的口腔感觉认知，可能与肥胖易感性有关。本研究检验了以下假设：易肥胖（OP，奥斯本-孟德尔大鼠）和抗肥胖（OR，S5B/Pl大鼠）大鼠对脂肪/脂肪酸的偏好是由营养状况和舌部CD36介导的。为了确定营养状况是否影响OP和OR大鼠对亚油酸（LA）的偏好，大鼠要么禁食过夜，要么喂食高脂饮食（60%千卡来自脂肪）。在OR大鼠中，禁食增加了对较高浓度LA（1.0%）的偏好，而食用高脂饮食则降低了LA偏好。在OP大鼠中，禁食增加了对较低浓度LA（0.25%）的偏好，然而食用高脂饮食并未改变LA偏好。为了确定舌部CD36是否介导了过夜禁食对LA偏好的影响，评估了舌部CD36 mRNA的表达，并确定了舌部应用CD36 siRNA对LA偏好的影响。禁食增加了OR大鼠舌部CD36 mRNA的表达，但未能改变OP大鼠舌部CD36 mRNA的表达。过夜禁食后，舌部应用CD36 siRNA导致OR大鼠而非OP大鼠的LA偏好降低。舌部应用CD36 siRNA还用于确定舌部CD36是否介导了OP和OR大鼠对高脂饮食的摄入和偏好。CD36 siRNA降低了OR大鼠对高脂饮食的偏好和摄入量，但未降低OP大鼠的。本研究结果表明，OP大鼠舌部CD36的失调是导致脂肪摄入量增加、脂肪偏好增强以及肥胖易感性增加的一个潜在因素。
