Division of Psychobiology, Yerkes National Primate Research Center, Emory University, Atlanta, GA 30329, USA.
Physiol Behav. 2011 Mar 1;102(3-4):382-8. doi: 10.1016/j.physbeh.2010.11.031. Epub 2010 Dec 3.
Gonadal steroids regulate appetite and thus body weight. In addition, continuous exposure to stressors negatively influences appetite through circuits likely distinct from those of gonadal steroids. The occurrence of adverse metabolic consequences due to chronic exposure to psychosocial stressors is twice as frequent in women as men, implicating a role for ovarian hormones, estradiol (E2) and progesterone (P4), in modulating stress-induced changes in appetite. Using social subordination in female macaques as a model of social stress, the current study tested the hypothesis that subordinate females would lose more weight during E2 treatment and gain less weight during P4 administration than dominant females. Because polymorphisms in the gene encoding the serotonin transporter (5HTT; SCL6A4) are known to alter responsivity to stress, we hypothesized that weight loss during E2 administration would be greatest in females with the short variant (s-variant) allele of 5HTT. Dominant females were significantly heavier than subordinate animals throughout the study, a result consistent with previous accounts of food intake when animals are fed a low-fat, high-fiber diet. Females with the s-variant 5HTT genotype weighed significantly less than l/l animals. Dominant animals lost significantly more weight than subordinate animals during E2 treatment. Administration of P4 blocked the weight-reducing effects of E2 in all females, regardless of social status. These data provide evidence that social subordination modulates the influence of ovarian steroid hormones on body weight in female rhesus monkeys independent of 5HTT genotype. Given the prosocial effects of these steroids, future studies are necessary to determine whether status differences in E2-induced weight loss are due to diminished food intake and or increases in energy expenditure and how the change in energy availability during E2 treatments relates to a female's motivation to interact with conspecifics.
性腺类固醇调节食欲，从而影响体重。此外，持续暴露于应激源会通过可能与性腺类固醇不同的途径对食欲产生负面影响。由于慢性暴露于心理社会应激源而导致不良代谢后果的发生在女性中比男性高两倍，这表明卵巢激素、雌二醇（E2）和孕酮（P4）在调节应激引起的食欲变化方面发挥作用。本研究使用雌性猕猴的社会从属关系作为社会应激的模型，检验了以下假设：与优势雌性相比，从属雌性在 E2 治疗期间体重减轻更多，而在 P4 给药期间体重增加更少。由于编码血清素转运体（5HTT；SCL6A4）的基因中的多态性已知会改变对压力的反应性，我们假设在 E2 给药期间体重减轻在 5HTT 的短变异体（s-变异体）等位基因的女性中最大。在整个研究过程中，优势雌性的体重明显高于从属动物，这与之前关于动物在低脂肪、高纤维饮食时的进食量的报道一致。携带 s-变体 5HTT 基因型的雌性比 l/l 动物体重明显更轻。与从属动物相比，优势动物在 E2 治疗期间体重减轻更为显著。在所有雌性动物中，P4 的给药阻断了 E2 的减重作用，而与社会地位无关。这些数据提供了证据，表明社会从属关系调节了卵巢类固醇激素对雌性恒河猴体重的影响，而与 5HTT 基因型无关。鉴于这些类固醇具有亲社会作用，未来的研究有必要确定 E2 诱导的体重减轻中地位差异是否归因于食物摄入量减少和/或能量消耗增加，以及 E2 治疗期间能量供应的变化与女性与同类互动的动机有何关系。
