Effects of intracerebroventricular administration of irisin on the hypothalamus-pituitary-gonadal axis in male rats

Irisin is a product of fibronectin type III domain-containing protein 5 (FNDC5) and plays an important role in energy homeostasis. In this study, we aimed to determine effects of intracerebroventricular administration of irisin on the hypothalamus-pituitary-gonadal axis by molecular, biochemical, and morphological findings. Fourty male Wistar-Albino rats were used and divided into four groups including control, sham (vehicle), 10, and 100 nM irisin infused groups (n = 10). Hypothalamic gonadotropin releasing hormone (GnRH) level and serum luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone levels were determined. Testicular tissue histology and spermiogram analysis were also performed. Both irisin concentrations significantly reduced hypothalamic GnRH messenger RNA (mRNA) and protein levels (p < 0.05). It was found that serum LH, FSH, and testosterone levels and Sertoli and Leydig cell numbers were decreased by irisin administration (p < 0.05). In addition, irisin administration reduced sperm density and mobility (p < 0.05). However, it did not cause any change in testicular and epididymis weights and tubular diameter. Our results reveal that irisin can play a role in the central regulation of reproductive behavior and also reduces testosterone levels by suppressing LH and FSH secretion. These results suggest that the discovery of irisin receptor antagonists may be beneficial in the treatment of infertility.

Journal of cellular physiology. 2018 Oct 14 [Epub ahead of print]

Suat Tekin, Ali Beytur, Yavuz Erden, Asiye Beytur, Yilmaz Cigremis, Nigar Vardi, Yusuf Turkoz, Ibrahim Tekedereli, Suleyman Sandal

Department of Physiology, Faculty of Medicine, Inonu University, Malatya, Turkey., Department of Urology, Faculty of Medicine, Inonu University, Malatya, Turkey., Department of Molecular Biology and Genetics, Faculty of Science, Bartin University, Bartin, Turkey., Department of Medical Biology and Genetics, Faculty of Medicine, Inonu University, Malatya, Turkey., Department of Histology and Embryology, Faculty of Medicine, Inonu University, Malatya, Turkey., Department of Medical Biochemistry, Faculty of Medicine, Inonu University, Malatya, Turkey.

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