Effects of Diabetes Mellitus on the Relaxation of Rabbit Vaginal Smooth Muscle / 대한비뇨기과학회지

PURPOSE: Diabetic women commonly reported decreased sexual arousal and a lack of vaginal lubrication. Genital arousal depends on the vaginal blood flow and the vaginal smooth muscle tone. The aim of this study was to investigate the effect of diabetes mellitus on the relaxation of the vaginal smooth muscles in the rabbit models. MATERIALS AND METHODS: New Zealand White female rabbits (3-3.5kg) were divided into two groups: control (n=5) and experimental (n=20). The experimental group received an intravenous injection of alloxan (100mg/kg). The development of diabetes was verified by measuring the body weight and blood glucose levels. After 12 weeks, the reactivity of the vaginal tissue from the control and diabetic animals was studied examined in the organ chambers. Vaginal The vaginal tissue was also processed immunohistochemically to determine the presence of the neuronal NOS isoform (n-NOS) in similar groups of rabbits. RESULTS: By After 12 weeks, five 5 of the 20 animals developed diabetes mellitus. The mean blood glucose level was significantly increased higher in the experimental group (340.8+/-116.9 mg/dl) compared to the control group (81.3+/-6.2mg/dl) (p=0.004). There was no significant difference in terms of the rRelaxation of vaginal tissue to electrical stimulation of the autonomic nerves, to the endothelium-dependent vasodilator acetylcholine and to the endothelium-independent vasodilator nitroprruside was not significantly different between the control and diabetic group. n-NOS immunoreactivity was also similar in both the control and diabetic groups. CONCLUSIONS: This The results suggest that diabetes mellitus may does not impair the neurogenic and endothelium-dependent relaxation of the rabbit vaginal smooth muscle. However, further intensive studies areinvestigation is needed to verify these results.

Role of Nitric Oxide in the Relaxation of Rabbit Vaginal Smooth Muscle / 대한비뇨기과학회지

PURPOSE: Vaginal engorgement depends, in part, on the relaxation of vaginal smooth muscle. The aim of this study was to evaluate the role of nitric oxide(NO) in the relaxation of the vaginal smooth muscle. MATERIALS AND METHODS: New Zealand White female rabbits(n=8) were sacrificed and distal 1/3 of the vagina was dissected. Strips of vaginal tissues were immediately processed for isometric tension measurement in the organ bath. The vaginal strips were precontracted with phenylephrine and the responses to electrical field stimulation(EFS) or sodium nitroprusside were examined. Each preparations was also processed immunohistochemically to determine the presence of neuronal NO synthase(n-NOS) in the tissue. RESULTS: EFS caused a frequency-dependent relaxation, which was significantly inhibited in the presence of Nw-nitro-L-arginine methyl ester(L-NAME), a competitive inhibitor of NOS. Sodium nitroprusside, a NO donor, caused concentration-dependent relaxations in the vaginal tissue and the relaxation was not affected by L-NAME(10-4M). n-NOS immunoreactivity was detected in perivascular space and vicinity of vaginal smooth muscle. CONCLUSIONS: These results suggest that the relaxation of the rabbit vaginal smooth muscle is partly mediated by the NO pathway.