Expression of the kisspeptin/kiss1r system in the hypothalamic arcuate nucleus of rats with diet-induced obesity and its influence on the hypothalamic-pituitary-testis axis / 中华男科学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To explore the expressions and functions of the kisspeptin/kiss1r system and GnRH in the hypothalamic arcuate nucleus (HAN) and the influence of the kisspeptin/kiss1r system on the hypothalamic-pituitary-testis (HPT) axis in the rat models of diet-induced obesity.</p><p><b>METHODS</b>Ninety newborn SD male rats were randomly assigned to receive normal diet (n = 30) and high-fat diet (n = 60) for the establishment of obesity models. The model rats were again equally divided into a control group and an experimental group, the latter injected with kisspeptin via the lateral ventricle. Then the body mass index (BMI) and endocrine hormone levels of the rats were recorded, the protein expressions of LepR, kisspeptin, kiss1r, and GnRH in the HAN determined by immunohistochemistry and Western blot, and the levels of GnRH mRNA in the HAN measured by qRT-PCR.</p><p><b>RESULTS</b>Significantly increased BMI and hormone levels indicated the successful establishment of diet-induced obesity models. Compared with the normal rats, the protein expressions of LepR, kisspeptin, and GnRH in the HAN were markedly decreased in the controls, and that of GnRH and the levels of LH and T significantly increased, but the expressions of LepR and kiss1r showed no remarkable changes in the experimental rats.</p><p><b>CONCLUSION</b>Lateral ventricular injection of kisspeptin can upregulate obesity-induced low expression of GnRH, correct the dysfunction of the HPT axis, and thus improve reproductive function in rats.</p>