Premium
Gonadotropin‐Releasing Hormone Exhibits Circadian Rhythm in Phase with Arginine‐Vasopressin in Co‐Cultures of the Female Rat Preoptic Area and Suprachiasmatic Nucleus
Author(s) -
Funabashi T.,
Shinohara K.,
Mitsushima D.,
Kimura F.
Publication year - 2000
Publication title -
journal of neuroendocrinology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.062
H-Index - 116
eISSN - 1365-2826
pISSN - 0953-8194
DOI - 10.1046/j.1365-2826.2000.00481.x
Subject(s) - suprachiasmatic nucleus , vasopressin , endocrinology , medicine , circadian rhythm , biology , preoptic area , neuropeptide , vasoactive intestinal peptide , hypothalamus , arginine , light effects on circadian rhythm , period (music) , receptor , biochemistry , amino acid , physics , acoustics
To determine whether the suprachiasmatic nucleus can drive a circadian release of gonadotropin‐releasing hormone (GnRH) in the preoptic area, we measured the release of GnRH, arginine‐vasopressin and vasoactive intestinal polypeptide (VIP) in cocultures of the preoptic area and the suprachiasmatic nucleus at 2‐h intervals over a period of 120 h. The release of GnRH in cocultures exhibited a significant circadian rhythm in the presence of oestrogen but not in the absence of oestrogen. The period of the GnRH circadian rhythm was the same as that of the arginine‐vasopressin circadian rhythm, and different from the VIP circadian rhythm in each coculture. Furthermore, the peak phase of the GnRH rhythm occurred at the time same as that of the arginine‐vasopressin rhythm in each coculture. However, the peak phase of the GnRH rhythm was not always the same as that of the VIP rhythm. Administration of arginine‐vasopressin significantly increased GnRH release in single preoptic area cultures in the presence of oestrogen, but VIP did not. The result suggests that, in cocultures of the suprachiasmatic nucleus and the preoptic area, arginine‐vasopressin neurones drive the circadian release of GnRH in the presence of oestrogen. We suggest that arginine‐vasopressin neurones in the suprachiasmatic nucleus mediate the clock information to GnRH neurones in vivo as well.