Forskning
Udskriv Udskriv
Switch language
Region Hovedstaden - en del af Københavns Universitetshospital
Udgivet

Circadian control of kisspeptin and a gated GnRH response mediate the preovulatory luteinizing hormone surge

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

DOI

  1. Evidence for glucagon secretion and function within the human gut

    Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

  2. Using a Reporter Mouse to Map Known and Novel Sites of GLP-1 Receptor Expression in Peripheral Tissues of Male Mice

    Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

  3. Repeated Activation of Noradrenergic Receptors in the Ventromedial Hypothalamus Suppresses the Response to Hypoglycemia

    Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

  4. Hypophosphatemic Hypovitaminosis D induces Osteomalacia in the adult female rat

    Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

  5. Activin A determines steroid levels and composition in the fetal testis

    Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

Vis graf over relationer
In spontaneously ovulating rodents, the preovulatory LH surge is initiated on the day of proestrus by a timed, stimulatory signal originating from the circadian clock in the suprachiasmatic nucleus (SCN). The present studies explored whether kisspeptin is part of the essential neural circuit linking the SCN to the GnRH system to stimulate ovulation in Syrian hamsters (Mesocricetus auratus). Kisspeptin neurons exhibit an estrogen-dependent, daily pattern of cellular activity consistent with a role in the circadian control of the LH surge. The SCN targets kisspeptin neurons via vasopressinergic (AVP), but not vasoactive intestinal polypeptide-ergic, projections. Because AVP administration can only stimulate the LH surge during a restricted time of day, we examined the possibility that the response to AVP is gated at the level of kisspeptin and/or GnRH neurons. Kisspeptin and GnRH activation were assessed after the administration of AVP during the morning (when AVP is incapable of initiating the LH surge) and the afternoon (when AVP injections stimulate the LH surge). Kisspeptin, but not GnRH, cellular activity was up-regulated after morning injections of AVP, suggesting that time-dependent sensitivity to SCN signaling is gated within GnRH but not kisspeptin neurons. In support of this possibility, we found that the GnRH system exhibits pronounced daily changes in sensitivity to kisspeptin stimulation, with maximal sensitivity in the afternoon. Together these studies reveal a novel mechanism of ovulatory control with interactions among the circadian system, kisspeptin signaling, and a GnRH gating mechanism of control.
OriginalsprogEngelsk
TidsskriftEndocrinology
Vol/bind152
Udgave nummer2
Sider (fra-til)595-606
Antal sider12
ISSN0013-7227
DOI
StatusUdgivet - 2011

ID: 33248003