Influence of oestradiol and progesterone on the expression of LH-hCG receptors in the porcine broad ligament
This study investigated an influence of oestradiol and progesterone on expression of LH/hCG receptors in the porcine uterine broad ligament. The tissues were obtained from nineteen ovariectomized crossbred gilts. The animals received i.m. injections of 2 ml of corn oil (control; n=4), 25 μg kg-1 of oestradiol benzoate (n=5), 500 μg kg-1 of progesterone (n=5) or 25 μg kg-1 of oestradiol benzoate with 500 μg kg-1 of progesterone (n=5) daily for 5 consecutive days before slaughter. It was found that oestradiol increased the number of receptors in arteries of all areas in the uterine broad ligament, in veins located near the uterine horn and in the ovarian vein as well as in the ligament musculature in the area of vessels located near uterine horn. Progesterone decreased the expression of receptors in all tissues from the area of vessels located about 4 cm below the uterine horn, but augmented their expression in the ovarian vein and in muscular layers of the broad ligament in the area of the uterine vessels trunk. Oestradiol with progesterone increased amount of receptors in arteries from the area of uterine vessels branches, in ovarian vessels^ in veins from areas of branches and trunk of uterine vessels as well as in muscular layers of the broad ligament collected from areas of uterine vessels trunk and paraovarian plexus. These results indicate that oestradiol and progesterone are responsible for changes in expression and distribution of LH/hCG receptors in the broad ligament of the porcine uterus.