Vascular endothelial growth factor (VEGF) and inducible nitric oxide synthase (iNOS) immunoreactivities in rat ovaries and uterine tubes after tubal ligation: a controlled immunohistochemical study.

摘要

OBJECTIVE: To evaluate the effects of tubal ligation on ovarian and tubal tissues by means of immunohistochemical evaluation of two hypoxia related mediators: vascular endothelial growth factor (VEGF) and inducible nitric oxide synthase (iNOS). DESIGN: Fourteen Sprague-Dawley female rats were divided into two groups: a tubal ligation (Pomeroy technique) was carried out on rats in group 1 (n = 7) whereas those in group 2 served as controls (n = 7). Salpingo-oophorectomy was performed in group 1 during the second oestrous period following tubal ligation. Rats in group 2 were submitted to a salpingo-oophorectomy, as well. VEGF and iNOS immunoreactivities in ovarian and tubal tissues were evaluated by means of immunohistochemistry. Immunohistochemical scores and number of antral follicles were compared. RESULTS: In the ovary, VEGF immunoreactivity was significantly more intense in the granulosa (p = 0.002) and the theca cells (p = 0.001) of rats in group 1 but, in ovarian medulla (p = 0.259) and germinal epithelium (p = 0.209), it was not significantly different from that of rats in group 2. The iNOS immunoreactivity in ovarian granulosa cells (p = 0.073) and germinal epithelial cells (p = 0.805) did not differ between the two groups. The cytoplasmic VEGF (p = 0.001) and iNOS (p = 0.017) immunoreactivities in the uterine tube, were significantly more intense in group 1. However, VEGF immunoreactivity in the lamina propria of the uterine tube (p = 0.209) was of similar intensity in both groups. CONCLUSION: Tubal ligation may lead to supraphysiological hypoxia as evidenced by increased VEGF and iNOS immunoreactivities in ovarian and tubal tissues.