Vasoactive intestinal peptide expression in the vaginal anterior wall of patients with pelvic organ prolapse.

OBJECTIVE: Perimenopausal women are at high risk for pelvic organ prolapse (POP) and stress urinary incontinence (SUI) diseases. In the present study, the expression of VIP in the vaginal epithelium of 70 perimenopausal women was correlated with the severity of POP with or without SUI.

MATERIALS AND METHODS: Seventy biopsy specimens from the anterior vaginal epithelium were obtained from postmenopausal patients. Immunohistochemical labeling for vasoactive intestinal peptide (VIP) and hematoxylin and eosin staining were performed. The VIP innervation was then compared between eight patient groups. Semiquantitative analysis of VIP protein by Western blotting was performed and compared between the eight patient groups.

RESULTS: The results of the immunohistochemical study showed that the intensity of VIP-immunoreactivity (VIP-ir) in the eight groups was as follows (in decreasing order): Control; POPI; POP II; POP II + SUI; POP III; POP IV and POP III + SUI; and POP IV + SUI. The intensity of VIP-ir was obviously weak and similar among the POP IV, POP III + SUI, and POP IV + SUI groups. This result was validated by the Western blotting analysis. The level of the VIP peptide also deceased in POP patients and was as follows (in decreasing order): Control; POPI; POP II and POP II + SUI; POP III and POP III + SUI; and POP IV and POP IV + SUI.

CONCLUSION: The present study found that reduced VIP innervation in the vaginal epithelium of the perimenopausal women was correlated with the severity of POP with or without SUI.