Kisspeptin mRNA expression is increased in the posterior hypothalamus in the rat model of polycystic ovary syndrome.
Hypersecretion of luteinizing hormone (LH) is a common endocrinological finding of polycystic ovary syndrome (PCOS). This derangement might have a close relationship with hypothalamic kisspeptin expression that is thought to be a key regulator of gonadotropin-releasing hormone (GnRH). We evaluated the relationship between the hypothalamic-pituitary-gonadal axis (HPG axis) and kisspeptin using a rat model of PCOS induced by letrozole. Letrozole pellets (0.4 mg/day) and control pellets were placed subcutaneously onto the backs of 3-week-old female Wistar rats. Body weight, vaginal opening and vaginal smear were checked daily. Blood and tissues of ovary, uterus and brain were collected at 12-weeks of age. An hypothalamic block was cut into anterior and posterior blocks, which included the anteroventral periventricular nucleus (AVPV) and the arcuate nucleus (ARC), respectively, in order to estimate hypothalamic kisspeptin expression in each area. The letrozole group showed a similar phenotype to human PCOS such as heavier body weight, heavier ovary, persistent anovulatory state, multiple enlarged follicles with no corpus luteum and higher LH and testosterone (T) levels compared to the control group. Kisspeptin mRNA expression in the posterior hypothalamic block including ARC was higher in the letrozole group than in the control group although its expression in the anterior hypothalamic block was similar between groups. These results suggest that enhanced KNDy neuron activity in ARC contributes to hypersecretion of LH in PCOS and might be a therapeutic target to rescue ovulatory disorder of PCOS in the future.
Department of Obstetrics and Gynecology, Graduate School of Biomedical Sciences, Tokushima University, Tokushima 770-8503, Japan.
Toshiya
T
Matsuzaki
Altankhuu
A
Tungalagsuvd
Takeshi
T
Iwasa
Munkhsaikhan
M
Munkhzaya
Rie
R
Yanagihara
Takako
T
Tokui
Kiyohito
K
Yano
Yiliyasi
Y
Mayila
Takeshi
T
Kato
Akira
A
Kuwahara
Sumika
S
Matsui
Minoru
M
Irahara
D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D007034:Hypothalamus, Posterior / Q000378:metabolism* / Q000473:pathology; D059648:Kisspeptins / Q000235:genetics* / Q000378:metabolism; D000077289:Letrozole; D009570:Nitriles; D011085:Polycystic Ovary Syndrome / Q000139:chemically induced / Q000235:genetics* / Q000473:pathology; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D014230:Triazoles; D015854:Up-Regulation
D059648:Kisspeptins; D009570:Nitriles; D012333:RNA, Messenger; D014230:Triazoles; D000077289:Letrozole