|Barb, Claude -|
Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: May 11, 2012
Publication Date: February 20, 2013
Citation: Lents, C.A., Barb, C.R., Hausman, G.J. 2013. Role of adipose secreted factors and kisspeptin in the metabolic control of gonadotropin secretion and puberty. In: Vizcarra, J., editor. Gonadotropin. New York, NY: In-Tech. pp. 25-56. DOI: 10.5772/48802. Interpretive Summary: Onset of puberty and the establishment of regular reproductive cycles are dependent upon increased release of reproductive hormones called gonadotropins from the anterior pituitary gland. The increased secretion of gonadotropin hormones is controlled by neurons in the hypothalamus of the central nervous system that produce a signaling molecule called kisspeptin. Adipose tissue expresses and secretes a wide array of regulatory biochemical factors that have been linked to important physiological functions. Shifts in metabolism cause changes in the synthesis and release of hormones and metabolites, such as free fatty acids, leptin, nesfatin-1 and adiponectin, from adipose tissue, which act at the hypothalamus to regulate food intake and reproductive function. Kisspeptin is a key part of the central pathway through which metabolism and adipose-secreted hormones affect reproduction. Infertility observed in animals with alterations in circulating concentrations of secreted adipose factors can partially be explained by suppression of kisspeptin. Continued examination of the developmental relationship of adipose tissue and its secreted factors with kisspeptin will ultimately result in improvements in the capability to control onset of puberty and minimize infertility.
Technical Abstract: Factors secreted by adipose tissue continue to be discovered. Evidence indicates a strong link between neural influences and adipocyte expression and secretion of a wide array of cytokines, neurotrophic factors, growth factors, binding proteins, and neuropeptides. These “adipokines” are linked to important physiological functions. Developmental changes in expression and secretion of these factors are considered important for the sequential activation of gonadotropin secretion at onset of puberty. Metabolic shifts cause changes in the synthesis and release of adipose secreted hormones and metabolites, which act at the hypothalamus to regulate food intake and reproductive function. Neuronal pathways linking appetite and release of gonadotropin hormones will be reviewed. Emphasis is placed on the influence that adipose derived factors such as free fatty acids, nesfatin-1, leptin, and adiponectin have in the secretion of gonadotropin-releasing hormone (GnRH) from the hypothalamus and luteinizing hormone (LH) from the pituitary gland. The function of the hypothalamic kisspeptin system in linking energy metabolism with reproduction is examined. Emphasis is placed on developmental changes in these systems during maturation of the gonadotropic axis during the pubertal transition.