Role of luteinizing hormone in control of oviduct function

The Fallopian tube plays a critical role in reproduction by being the site of fertilization and early embryonic development. Recently it was shown tha t the oviduct is a novel target for luteinizing hormone (LH). LH receptor m RNA is present in the porcine oviduct. LH/hCG receptors were detected in th e epithelium of the tubal mucosa and smooth muscle cells of the pig myosalp inx. Western blotting revealed that the porcine oviduct contains mainly 75 kDa immunoreactive LH receptor protein. Treatment with LH in vitro caused r elaxation of the oviduct, especially during the peri-ovulatory stage of the oestrous cycle. There is also evidence that combined estradiol and progest erone priming is necessary for LH-induced relaxation of the oviduct in ovar iectomized pigs. The results of these investigation indicate that LH should be added to the list of factors affecting oviduct function and it is sugge sted that LH, in addition to causing the rupture of follicles and luteiniza tion of granulosa and theca cells, also plays an important role in controll ing oviductal contractions.