Presence of CBG (corticosteroid binding globulin) estrogen receptors alpha and progesterone receptors along the reproductive tract in sheep during different stages of the reproductive cycle. Inmunohistochemestry study

The steroids hormones operate through their receptors in the development of the genital tract and determine it morphofuncional state. The objective of the present study was to investigate the presence of CBG (corticosteroid binding globulin), estrogens alpha and progesterone receptors in the uterus, oviduct and ovary of sheep during oestrous cycle (n = 3), pregnancy (n = 3), and in anoestrous (n = 3). Cross sections were stained with Hematoxylin-eosin and Inmunohistochemical (ICQ) study was made according to the technique of Sternberger. The results showed for estrogens receptors in sheep on cycle estral, moderate positive immunoreaction in the estroma and on the epithelial cells of endometrial glands and in oviductal superficial epithelium and estroma; the immunoreaction in pregnant and anestrics sheep was low. The progesterone receptors had in the 3 organs moderate immunorreactivity in cycling sheep and immunorreactivity low or negative in acycling animals. The CBG endometrial immunorreaction was high in cycling sheep and low or negative in pregnant and anestrics. The CBG in sheep during the cycle demonstrated a positive reaction at ovarian level in follicular cells, inside follicular liquid, and in stromal cells filled with granulate material disseminated in groups or isolated. In conclusion, the presence of estrogens alpha and progesterone receptors are always detectable in uterus, oviduct and ovary varying their concentration according to the stage The presence of CBG was constant in the three organs during the oestral cycle and variable in the other stages, its participation in the reproductive process is topic for next studies.