Chronic anxiety, depression or physical exertion-associated stress consistently activates the hypothalamic-pituitary-adrenal (HPA) axis. Each individual component of the HPA axis, such as CRH, ACTH, β-endorphin or glucocorticoid exerts deleterious effect on the hypo-thalamic-pituitary-gonadal (HPG) axis and subsequently leads to reproductive failure. Gonadotropin-releasing hormone (GnRH) secret...

background: the hormones of hypothalamo-pituitary-gonadal (hpg) axis have facilitative effects on reproductive behavior in mammals. ghrelin as a starvation hormone has an inhibitory effect on hpg axis’ function. hence, it is postulated that ghrelin may reduce the sexual behavior through inhibiting of hpg axis. the aim of this study was to examine the effects of ghrelin and its antagonist, [d-ly...

In Persian traditional medicine is believed that camphor (a crystalline ketone obtained from cinnamomum camphora) is a suppressor of sexual behaviors. This study examined the central effects of camphor on sexual hormones (LH, FSH and testosterone) and GnRH plasma levels in male rat. Male Wistar rats weighing 250-260gr were selected and divided into control (no treatment), sham (ICV injection of...

background: kisspeptin-gpr54 system stimulates the hypothalamus-pituitary-gonadal (hpg) axis; dysfunction of the gene encoding the gpr54 receptor causes hypogonadism and infertility. opioid peptides inhibit the reproductive axis. peptide 234 is a gpr54 receptor antagonist and blocks the stimulatory effects of kisspeptin on hpg axis. objectives: interactions of morphine, kisspeptin and peptide 2...

While stress activates the hypothalamic-pituitary-adrenal (HPA) axis, it suppresses the hypothalamic-pituitary-gonadal (HPG) axis. Corticotropin-releasing factor (CRF) is a major regulatory peptide in the HPA axis during stress. Urocortin 1 (Ucn1), a member of the CRF family of peptides, has a variety of physiological functions and both CRF and Ucn1 contribute to the stress response via G prote...

The hypothalamic-pituitary-gonadal (HPG) axis plays a critical role in the control of reproduction. Two key hormonal components of the HPG axis are gonadal steroids and gonadotropin-releasing hormone (GnRH). Gonadal steroids are known to organize the development of neural substrates which control adult reproductive behavior; GnRH is required for normal reproductive structure and function. The p...

Disorders of reproduction represent a significant social, medical, and economic burden for individuals and society. Approximately 1 in 10 couples in the United States are infertile, and each partner is equally likely to be affected (1). Although many causes of infertility can now be determined in both men and women, most couples still receive a diagnosis of idiopathic infertility. A subset of t...

DeFries, Christa, "Regulation of levels and localization of thimet oligopeptidase in prostate cancer cells by β-estradiol" (2013). Honors Thesis Collection. Paper 161. Abstract The enzyme thimet oligopeptidease (TOP) catalyzes the hydrolysis of gonadotropin-releasing hormone (GnRH) in vitro, and evidence suggests that TOP is the primary enzyme responsible for GnRH hydrolysis in vivo, as well. I...

Understanding sources of individual differences in steroid hormone production has important implications for the evolution of reproductive and social behaviors. In females in particular, little is known about the mechanistic sources of these individual differences, despite established linkages between sex steroids and a variety of fitness-related traits. Using captive female dark-eyed juncos (J...

In many organisms, food availability is a proximate cue that synchronizes seasonal development of the reproductive system with optimal environmental conditions. Growth of the gonads and secondary sexual characteristics is orchestrated by the hypothalamic-pituitary-gonadal (HPG) axis. However, our understanding of the physiological mechanisms by which food availability modulates activity of the ...