title: Fasting reduces the kiss1 mRNA levels in the caudal hypothalamus of gonadally intact adult female rats.
abstract: Kisspeptin, which is the product of the kiss1 gene and its receptor kiss1r, have emerged as the essential gatekeepers of reproduction. The present study used gonadally intact female rats to evaluate fasting-induced suppression of the KiSS-1 system of anteroventral periventricular nucleus (AVPV) and arcuate nucleus (ARC) under normal physiological conditions.  Starting on the day of estrous, one group of rats was subjected to 72 h of food deprivation, while the other group of rats was able to continue feeding ad libitum.  The length of the estrous cycle was significantly longer in the food-deprived rats as compared to the feeding rats.  At the end of the 72-h food deprivation period, all of the food-deprived rats were at the diestrous phase, with their serum concentrations of LH and leptin significantly lower than that observed in the feeding rats.  In addition, as compared to the feeding rats, the expression levels of kiss1 mRNA were significantly lower in the food-deprived rats in the posterior hypothalamic block, which contained the ARC, but not in the anterior hypothalamic block, which contain the AVPV.  However, both the kiss1r mRNA expression levels in the anterior and posterior hypothalamic blocks and the neurokinin B and neurokinin 3 receptor mRNA expression levels in the posterior hypothalamic block were not significantly different between the feeding and food-deprived rats.  Thus, lower kiss1 mRNA levels in the ARC appear to be responsible for the fasting-induced inhibition of gonadotrophin secretion and subsequent prolongation of the estrous cycle.
authors: Department of Obstetrics and Gynecology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima 770-8503, Japan. mat@clin.med.tokushima-u.ac.jp
authors: Toshiya
authors: T
authors: Matsuzaki
authors: Takeshi
authors: T
authors: Iwasa
authors: Riyo
authors: R
authors: Kinouchi
authors: Shinobu
authors: S
authors: Yoshida
authors: Masahiro
authors: M
authors: Murakami
authors: Ganbat
authors: G
authors: Gereltsetseg
authors: Satoshi
authors: S
authors: Yamamoto
authors: Akira
authors: A
authors: Kuwahara
authors: Toshiyuki
authors: T
authors: Yasui
authors: Minoru
authors: M
authors: Irahara
mesh_terms: D000818:Animals; D030762:Estrous Cycle / Q000502:physiology; D005260:Female; D005508:Food Deprivation / Q000502:physiology*; D007031:Hypothalamus / Q000378:metabolism / Q000502:physiology*; D059648:Kisspeptins / Q000235:genetics / Q000378:metabolism*; D020738:Leptin / Q000097:blood; D007986:Luteinizing Hormone / Q000097:blood; D015287:Neurokinin B / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D060888:Real-Time Polymerase Chain Reaction; D043562:Receptors, G-Protein-Coupled / Q000235:genetics / Q000378:metabolism; D000074502:Receptors, Kisspeptin-1; D018042:Receptors, Neurokinin-3 / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: C491406:Kiss1 protein, rat; C492247:Kiss1r protein, rat; D059648:Kisspeptins; D020738:Leptin; D012333:RNA, Messenger; D043562:Receptors, G-Protein-Coupled; D000074502:Receptors, Kisspeptin-1; D018042:Receptors, Neurokinin-3; D015287:Neurokinin B; D007986:Luteinizing Hormone