Biology Reference
In-Depth Information
Chapter 5
Effects of Kisspeptin on Hormone Secretion
in Humans
Yee-Ming Chan
Abstract Studies of the actions of kisspeptin in human subjects have examined the
effects of different kisspeptin isoforms, doses, and routes of administration on LH
secretion, a surrogate measure of GnRH release. These studies, in addition to detail-
ing how these different variables affect LH secretion in response to kisspeptin, have
produced new insights into kisspeptin physiology: (1) Brief exposure to kisspeptin
results in sustained GnRH release lasting ~17 min in men. (2) Women in different
phases of the menstrual cycle have differences in their response to kisspeptin, sug-
gesting that endogenous kisspeptin secretion and GnRH neuronal responsiveness
vary in response to the changing sex-steroid environment across the menstrual cycle.
(3) Kisspeptin resets the GnRH pulse generator in men, but does not appear to do so
in women. (4) Continuous exposure to kisspeptin results in desensitization to
kisspeptin, and thus kisspeptin has the potential to either stimulate or suppress repro-
ductive endocrine activity depending on the mode of administration. These fi ndings
pave the way for future studies using kisspeptin as a physiologic, diagnostic, and
therapeutic tool in both healthy adults and in patients with reproductive disorders.
Introduction
The role of kisspeptin in reproduction was discovered through genetic studies in both
humans and mice [ 1 - 3 ]. Since that initial discovery, studies predominantly in animal
models have revealed that the hypothalamic neurons that secrete kisspeptin are
Y.-M. Chan, M.D., Ph.D. ( * )
Division of Endocrinology, Department of Medicine, Boston Children's Hospital,
Boston , MA , USA
Reproductive Endocrine Unit and Harvard Reproductive Sciences Center,
Department of Medicine, Massachusetts General Hospital , Boston , MA , USA
e-mail: ymchan@partners.org
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