[Expression of KISS-1 and GnRH in rat hypothalamus].
OBJECTIVE
To assay the expression of KiSS-1 and GnRH in the male rat hypothalamus at different developmental stages, and to explore the significance of KiSS-1 in sex development onset and normal reproduction regulation.


METHODS
Expression analyses of KiSS-1 and GnRH genes were conducted in the rat hypothalamus at different developmental stages with RT-PCR and real time-PCR. The testosterone level was assayed by chemoluminescence technique.


RESULTS
KiSS-1 mRNA rose gradually during sex development in the rat hypothalamus, highest at puberty and lowered a little at adulthood. KiSS-1 mRNA of the prepubertal, early pubertal, pubertal and adult rats was 1.7, 2.1, 3.5 and 2.0 times higher than that of the infantile rats respectively. The expression of GnRH and KiSS-1 correlated positively (r = 0.905, P < 0.05). But the activation of GnRH neuron was later than KiSS-1. The expression of GnRH was the highest in the puberty rats. GnRH mRNA of the prepubertal, early pubertal, pubertal and adult rats was 1.1, 1.94, 2.42 and 1.92 times higher than that of the infantile rats respectively. The level of testosterone in the adult rats was significantly higher than that at the earlier stage and was the highest at the adult stage.


CONCLUSIONS
The expression of KiSS-1 correlates positively with that of GnRH. KiSS-1 may participate in the regulation of GnRH and is relevant to puberty onset and the regulation of reproduction function.
Wang
Xue-song
XS
Reproductive Medicine Center, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China.
Zhang
Cai-tian
CT
Ju
Xiao-bin
XB
Zhang
Zhao-hui
ZH
Ding
Gui-peng
GP
Chen
Zi-qing
ZQ
Su
En-ben
EB
Cui
Yu-gui
YG
D000818:Animals; D007987:Gonadotropin-Releasing Hormone / Q000096:biosynthesis* / Q000235:genetics; D007031:Hypothalamus / Q000378:metabolism*; D059648:Kisspeptins; D008297:Male; D011506:Proteins / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction
C491406:Kiss1 protein, rat; D059648:Kisspeptins; D011506:Proteins; D012333:RNA, Messenger; D007987:Gonadotropin-Releasing Hormone