Role of luteinizing hormone in control of oviduct function

Abstract

The Fallopian tube plays a critical role in reproduction by being the site of fertilization and early embryonic development. Recently it was shown that the oviduct is a novel target for luteinizing hormone (LH). LH receptor mRNA is present in the porcine oviduct. LH/hCG receptors were detected in the epithelium of the tubal mucosa and smooth muscle cells of the pig myosalpinx. Western blotting revealed that the porcine oviduct contains mainly 75 kDa immunoreactive LH receptor protein. Treatment with LH in vitro caused relaxation of the oviduct, especially during the peri-ovulatory stage of the oestrous cycle. There is also evidence that combined estradiol and progesterone priming is necessary for LH-induced relaxation of the oviduct in ovariectomized pigs. The results of these investigation indicate that LH should be added to the list of factors affecting oviduct function and it is suggested that LH, in addition to causing the rupture of follicles and luteinization of granulosa and theca cells, also plays an important role in controlling oviductal contractions.