PURPOSE: The objectives of this study were to evaluate the effects of cigarette smoking on vaginal blood flow and on histological change in a rat model. The specific aims of this study are as follows: 1) effects of acute exposure to passive cigarette smoking on vaginal blood flow and 2) effects of chronic exposure to cigarette smoking on vaginal structure and quantity of estrogen receptor. MATERIALS AND METHODS: 1) The Acute smoking model: female Sprague- Dawley rats (12 weeks old, n=5) were included in this study. To test? for the exposure to passive smoking, the rats, in a plastic enclosure, had a constant influx of cigarette smoke using a smoke generator. Vaginal blood flow was measured by the laser Doppler flowmeter. Arterial blood gas and serum nicotine concentration were measured before and 15 minute after exposure to cigarette smoke. 2) The Chronic smoking model: the experimental group was exposed to cigarette smoke for 1 hr per day, 5 days per week for 8 weeks. Serial sections of the vagina were processed in the H-E stain, Masson's trichrome stain, and in immunohistochemistry to observe the expression of TGF beta1 and estrogen receptor alpha. RESULTS: 1) The Acute smoking model: mean vaginal blood flow (ml/min/100g tissue) significantly decreased from 27.2+/-5.7 to 19.4+/-4.2 after exposure to cigarette smoke (p<0.05). In arterial blood gas analysis, PO2 (mmHg) and PCO2 (mmHg) changed from 56.2+/-8.1 and 46.0+/-6.3 to 66.3+/-10.6 and 53.5+/-2.7, respectively. 2) The Chronic smoking model: vaginal histology of the cigarette smoking group was similar to the control. In the cigarette smoking group, the immunoreactivity of TGF-beta1 slightly increased in the smooth muscle and fibroblasts, whereas the immunoreactivity of estrogen receptor alpha decreased. CONCLUSIONS: An acute exposure to cigarette smoke significantly reduces vaginal blood flow in the female rat model. A chronic exposure to cigarette smoke appears to cause vaginal tissue fibrosis. This suggest that cigarette smoking has adverse effects on female sexual functions and may cause sexual arousal disorder in women.
Animals ; Blood Gas Analysis ; Estrogen Receptor alpha ; Estrogens ; Female ; Fibroblasts ; Fibrosis ; Flowmeters ; Humans ; Immunohistochemistry ; Models, Animal ; Muscle, Smooth ; Nicotine ; Plastics ; Rats* ; Sexual Dysfunctions, Psychological ; Sexuality ; Smoke ; Smoking* ; Tobacco Products* ; Tobacco Smoke Pollution ; Transforming Growth Factor beta1 ; Vagina*