Erratum: Gonadotropin-Inhibitory Hormone Is a Hypothalamic Peptide That Provides a Molecular Switch between Reproduction and Feeding

<b><i>Objective:</i></b> Gonadotropin-inhibitory hormone (GnIH)-3 is a neuropeptide that plays a major role in the regulation of reproduction and feeding in mammals. <b><i>Materials and Methods:</i></b> We measured endocrine and behavioural parameters of reproduction in sheep, and sexual behaviour in sheep, mice and cynomolgus monkeys. In addition, GnIH gene expression (in situ hybridization) was examined in ewes, and effects of GnIH-3 on food intake and energy expenditure were measured in various species. GnIH-3 was infused (i.v.) into ewes after an i.m. injection of estradiol benzoate to determine whether the peptide blocks the surge in luteinizing hormone (LH) secretion. <b><i>Results:</i></b> GnIH gene expression was reduced in the preovulatory period in ewes. Infusion (i.v.) of GnIH-3 blocked the estrogen-induced LH surge (in ewes). Intracerebroventricular infusion had no effect on female or male sexual behaviour in each of the three species, but increased food intake. There were no effects on energy expenditure in sheep or rats. GnIH increased fos protein (immunohistochemistry) was seen in orexigenic neurons (in sheep and rats), but also in anorexigenic neurons (in sheep). <b><i>Conclusions:</i></b> GnIH-3 reduces reproductive hormone levels and increases food intake in mammals without reducing energy expenditure. There is minimal effect on reproductive behaviour. The dual effect on reproduction and feeding suggests that GnIH-3 provides a molecular switch between these two functions. Blockade of the positive feedback effect of estrogen with parenteral infusion indicates that this peptide may have utility as a blocker of reproductive function in mammals.

<b><i>研究目的：</i></b> 促性腺激素抑制激素（Gonadotropin-inhibitory hormone，GnIH）-3是一种在哺乳动物生殖与摄食调控中发挥关键作用的神经肽。<b><i>材料与方法：</i></b> 本研究检测了绵羊的生殖内分泌与行为参数，以及绵羊、小鼠和食蟹猴的性行为。此外，本研究通过原位杂交（in situ hybridization）技术检测了母羊的GnIH基因表达情况，并在多个物种中检测了GnIH-3对摄食量与能量消耗的影响。为明确该肽是否能阻断黄体生成素（Luteinizing hormone，LH）分泌峰，我们在苯甲酸雌二醇肌内（i.m.）注射后，对母羊进行了GnIH-3静脉内（i.v.）输注。<b><i>实验结果：</i></b> 母羊的GnIH基因表达在排卵前期显著降低。GnIH-3静脉内输注可阻断雌激素诱导的母羊LH分泌峰。脑室内（intracerebroventricular）输注对三个物种的雌雄个体性行为均无显著影响，但可增加摄食量。该肽对绵羊和大鼠的能量消耗无明显作用。通过免疫组织化学法（immunohistochemistry）检测发现，在绵羊与大鼠的促食欲神经元中可观察到GnIH诱导的fos蛋白表达，同时在绵羊的抑食欲神经元中也可检测到该蛋白。<b><i>研究结论：</i></b> GnIH-3可降低哺乳动物的生殖激素水平并增加摄食量，且不影响能量消耗。其对生殖行为的影响极小。对生殖与摄食的双重调控作用表明，GnIH-3可作为这两种生理功能间的分子开关。通过非肠道输注阻断雌激素的正反馈效应，提示该肽有望作为哺乳动物生殖功能的阻断剂。