The luteinizing hormone (LH), follicle-stimulating hormone (FSH) and testosterone response of bull calves implanted with estradiol-17 beta to continuous and pulsatile infusion of luteinizing hormone releasing hormone (LHRH) has been examined. Estradiol-17 beta reduced serum LH and FSH concentrations and suppressed testosterone secretion and testicular growth when compared with sham-implanted bu...

Energy balance plays an important role in the control of reproduction. However, the cellular and molecular mechanisms connecting the two systems are not well understood especially in teleosts. The hypothalamus plays a crucial role in the regulation of both energy balance and reproduction, and contains a number of neuropeptides, including gonadotropin-releasing hormone (GnRH), orexin, neuropepti...

Activation of the luteinizing hormone/human chorionic gonadotropin (LH/hCG) receptor (LHR) in cultured hypothalamic cells and immortalized GnRH (gonadotropin-releasing hormone) neurons (GT1-7 cells) transiently stimulates and subsequently inhibits cAMP production and pulsatile GnRH release. The marked and delayed impairment of cAMP signaling and episodic GnRH release in GT1-7 cells is prevented...

The effect of testicular binding of human chorionic gonadotropin upon the biological activities of the hormone was examined by comparison of the binding and activation properties of (125)I-labeled gonadotropin before and after binding to rat testis in vitro. Biologically active (125)I-gonadotropin taken up by rat testis was dissocated from testis binding-sites at low pH and evaluated for its ab...

Gonadotropin therapy plays an integral role in ovarian stimulation for infertility treatments. Efforts have been made over the last century to improve gonadotropin preparations. Undoubtedly, current gonadotropins have better quality and safety profiles as well as clinical efficacy than earlier ones. A major achievement has been introducing recombinant technology in the manufacturing processes f...