Expression of functional follicle-stimulating hormone receptor and luteinizing hormone/chorionic gonadotrophin receptor in oviduct and uterus in prepubertal gilts

The presence of the FSHR and LH/CGR in nongonadal tissues of reproductive tracts during estrus has been reported. But localization study for FSHR in the endometrium has not been performed. Moreover, the expression of FSHR and LH/CGR in the nongonadal tissues of prepubertal gilts is also unclear. Our objectives were to demonstrate the presence of active and functional LH/CGR and FSHR and to localize the two receptors in uterus and oviducts in prepubertal gilts. Fifteen prepubertal crossbred (Landrance/Yorkshine) gilts were used in the study. RT-PCR revealed that both uterus and oviducts contained a 145 bp LH/CGR transcript and a 103 bp FSHR transcript. Western blotting revealed that the two tissues also contained a 75 KDa immunoreactive LHR protein and a 75 KDa immunoreactive FSHR protein. Immunocytochemistry demonstrated that the LHR and FSHR were expressed both in the uterus and oviducts. In the oviducts, the two receptors were all present in the mucosal epithelium, but not detected in the myosalpinx and the serosa. In the uterus, they were present in the luminal and glandular epithelium of the endometrium. Furthermore, the vascular smooth muscle also expressed the LHR protein. Injection of eCG to ovariectomized gilts and intact gilts increased both the concentrations of FSH and LH in serum and expressions of FSHR and LH/CGR proteins in uterus and oviducts. In summary, active FSHR and LH/CGR are present in the uterus and oviducts of prepubertal gilts.