Department of Environmental Health, Nara Women's University, Kitauoya Nishimachi, Nara 630-8506, Japan.
Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK.
Nutrients. 2022 Mar 15;14(6):1235. doi: 10.3390/nu14061235.
Sex steroids modify feeding behavior and body weight regulation, and androgen reportedly augments food intake and body weight gain. To elucidate the role of endogenous androgens in the feeding regulation induced by reduced glucose availability, we examined the effect of gonadectomy (orchiectomy) on food intake and orexin A neuron's activity in the lateral hypothalamic/perifornical area (LH/PFA) in response to reduced glucose availability (glucoprivation) induced by 2-deoxy-d-glucose (2DG) administration in male rats. Rats (7W) were bilaterally orchiectomized (ORX group) or sham operated (Sham group). Seventeen days after the surgery, food intake response to 2DG (400 mg/kg, i.v.) was measured for 4 h after the infusion. The same experiment was performed for the immunohistochemical examination of c-Fos-expressing orexin A neurons in the LH/PFA and c-Fos expression in the arcuate nucleus (Arc). Food intake induced by glucoprivation was greater in the ORX group than the Sham group, and the glucoprivation-induced food intake was inversely correlated with plasma testosterone concentration. Glucoprivation stimulated c-Fos expression of the orexin A neurons at the LH/PFA and c-Fos expression in the dorsomedial Arc. The number and percentage of c-Fos-expressing orexin A neurons in the LH/PFA and c-Fos expression in the dorsomedial Arc were significantly higher in the ORX group than the Sham group. This indicates that endogenous androgen, possibly testosterone, diminishes the food intake induced by reduced glucose availability, possibly via the attenuated activity of orexin A neuron in the LH/PFA and neurons in the dorsomedial Arc.
性激素可调节摄食行为和体重调节，雄激素可增加食物摄入和体重增加。为了阐明内源性雄激素在降低葡萄糖供应引起的摄食调节中的作用，我们检查了去势（睾丸切除术）对雄性大鼠接受 2-脱氧-d-葡萄糖（2DG）给药引起的葡萄糖剥夺（低糖血症）时的食物摄入和下丘脑外侧/穹窿周区（LH/PFA）中食欲素 A 神经元活性的影响。大鼠（7W）双侧睾丸切除术（ORX 组）或假手术（Sham 组）。手术后 17 天，测量静脉注射 2DG（400mg/kg）后 4 小时的食物摄入量反应。进行了相同的实验，以检查 LH/PFA 中表达 c-Fos 的食欲素 A 神经元和弓状核（Arc）中 c-Fos 表达的免疫组织化学。ORX 组的低糖血症诱导的食物摄入量大于 Sham 组，并且低糖血症诱导的食物摄入量与血浆睾丸酮浓度呈负相关。低糖血症刺激 LH/PFA 中食欲素 A 神经元和背内侧 Arc 中的 c-Fos 表达。LH/PFA 中表达 c-Fos 的食欲素 A 神经元的数量和百分比以及背内侧 Arc 中的 c-Fos 表达在 ORX 组中明显高于 Sham 组。这表明内源性雄激素（可能是睾丸酮）通过减弱 LH/PFA 中的食欲素 A 神经元和背内侧 Arc 中的神经元的活性，减弱了由降低葡萄糖供应引起的食物摄入。
