The kisspeptins are critical regulators of mammalian reproduction. Kisspeptin-10 ((45)YNWNSFGLRF-NH2(54), kisspeptin-112-121 or metastin 45-54, NSC 741805), an active fragment of kisspeptin, has been shown to be a potent stimulator of gonadotropin-releasing hormone and secretion of luteinizing hormone in both rodents and primates. This shorter peptide fragment may have clinical utility potentia...

The aim of the present study was to clarify the effect of kisspeptin-10 on LH secretion in prepubertal ewes. In experiment 1, prepubertal ewes fitted with indwelling jugular catheters were randomly assigned to receive 0, 0.5, 1 or 2 mg of kisspeptin-10 dissolved in saline, and serial blood samples were collected at 15-min intervals for 180 min to analyze the response curves of LH after injectio...

Kisspeptin is the peptide product of the KiSS-1 gene and the endogenous agonist for the GPR54 receptor. Recent evidence suggests the kisspeptin/GPR54 system is a key regulator of the reproductive system. We examined the effect of intracerebroventricular (i.c.v.) and peripheral administration of the active kisspeptin fragment, kisspeptin-10, on circulating gonadotrophins and total testosterone l...

Kisspeptin is a hypothalamic peptide hormone that plays a pivotal role in pubertal onset and reproductive function. Previous studies have examined hypothalamic kisspeptin mRNA expression, either through in situ hybridisation or real-time RT-PCR, as a means quantifying kisspeptin gene expression. However, mRNA expression levels are not always reflected in levels of the translated protein. Kisspe...

CONTEXT Kisspeptins stimulate GnRH and thus gonadotropin secretion. Kisspeptin-10 is the minimal kisspeptin sequence with full intrinsic bioactivity, but it has not been studied in man. OBJECTIVE We investigated our hypothesis that kisspeptin-10 increases GnRH and thus LH pulse frequency. DESIGN AND PARTICIPANTS The dose response of kisspeptin-10 was investigated by administering iv bolus d...

The G-protein coupled receptor GPR54 and its ligand, KiSS-1-derived peptide kisspeptin-54, appear to play an important role in the mechanism of puberty. This study measures the release of kisspeptin-54 in the stalk-median eminence (S-ME) during puberty and examines its potential role in the pubertal increase in LHRH-1 release in female rhesus monkeys. First, developmental changes in release of ...

BACKGROUND Kisspeptin and naloxone stimulate the reproductive axis while morphine inhibits its function. We have investigated the effect of central injection of kisspeptin-10 on mean plasma testosterone concentration in morphine or naloxone pretreated rats. MATERIALS AND METHODS In this experimental study, 60 male Wistar rats that were divid- ed into 12 groups (n=5 per group) received saline,...

STUDY QUESTION Does sex-steroid feedback influence gonadotrophin responses to kisspeptin-10? SUMMARY ANSWER Gonadotrophin response to kisspeptin-10 is enhanced in sex-steroid deficient post-menopausal women and suppressed in women taking pharmacological doses of exogenous estrogen and progestogen. WHAT IS KNOWN ALREADY Kisspeptin, a novel hypothalamic neuropeptide, stimulates gonadotrophin ...

STUDY QUESTION How potently does the novel hypothalamic stimulator of reproduction, kisspeptin, increase gonadotrophin secretion when compared with GnRH in healthy men? SUMMARY ANSWER At the doses tested, intravenous administration of either of two major kisspeptin isoforms, kisspeptin-10 and -54, was associated with similar levels of gonadotrophin secretion in healthy men; however, GnRH was ...