Expression of Luteinizing Hormone (LH) and Its Receptor Gene in Uterus from Cycling Rats / 대한불임학회지

ABSTRACT

OBJECTIVE: There is increasing evidence for the expression of rat LH gene in several extrapituitary sites including testis and ovary. We also have demonstrated that the local LH expression in the rat epididymis and uterus, the major accessory sex organs in male and female reproductive system, respectively. DESIGN: The present study was undertaken to elucidate whether the gene for LH receptor is expressed in rat uterus and whether the expression of uterine LH and its receptor are differentially regulated during estrous cycle. Presence of the transcripts for rat LH receptor in the rat uterine tissue were confirmed by touchdown reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: In LHbeta semi-quantitative RT-PCR, the highest expression level was shown in estrus stage. The level of LH receptor transcripts was also fluctuated during estrous cycle. In ovariectomized rats (OVX + Oil), the expressions of both uterine LH and LH-R were markedly reduced when compared to those from normal rats. Supplement with estradiol 17beta to the ovariectomized rats (OVX + E2) restored the expression levels of LH and its receptor to the levels in uteri from normal rats. CONCLUSION: Our findings indicated that 1) LH and its receptor gene are expressed in the rat uterus from cycling rats, 2) the expression of uterine LH and its receptor is mainly, if not all, under the control of ovarian sex steroid(s). These results suggested that the uterine LH may act as a local regulator with auto and/or paracrine manner, though the posibility that the pituitary LH may act directly on the regulation of uterine functions could not be discarded.