Adiponectin in male reproduction and infertility

Adiponectin is an adipokine that has the highest plasma concentration among all other adipokines. It is a white adipose tissue secretion essential for the regulation of energy metabolism owing to its antiatherogenic insulin-resistance, and anti-inflammatory properties. Studies have put forth that adiponectin is a potent endocrine regulator with mechanisms relating energy balance with reproductive function in different species, including humans. The two adiponectin receptors, AdipoR1 and AdipoR2 have been found to be expressed in the prime regulatory axis of reproduction, the hypothalamic-pituitary-gonadal axis. The activation of adiponectin receptors has been shown to regulate the secretion and gene expressions of kisspeptin, gonadotropin-releasing hormone and gonadotropins. Adiponectin finds relevance in the regulations of most of the vital testicular functions, such as steroidogenesis, germ cell proliferation and their coordinated apoptosis, as well as in modulation of testicular redox status and oxidative stress. Since metabolic syndrome and their associations with male infertility have been gaining immense research interest, adiponectin seems to be one of the important mediators of metabolic syndrome-induced male reproductive dysfunctions. This article aims to review the patterns of adiponectin expression in the male reproductive tissues and the mechanism by which adiponectin modulates male reproductive functions.