Establishment of an In Vivo Rat Model to Investigate Female Vaginal Arousal Response

Kim, Tae Bum; Yang, Ji Hyun; Paick, Jae Seung; Kim, Soo Woong

Abstract

PURPOSE
We established a rat model to investigate the female vaginal arousal response and the effects of the estrous cycle on vaginal blood flow in vivo.
MATERIALS AND METHODS
Laser Doppler flowmetry was used to measure changes in vaginal blood flow induced by pelvic nerve stimulation(PNS) in 30 female Sprague-Dawley rats. Frequency response data were obtained in each animal. In addition, the rat's stage in the estrous cycle was determined according to the cell types observed in a vaginal smear. Changes in blood flow at 10 Hz frequency caused maximal response, and these responses were evaluated by comparing the relative peak flow, time to peak, duration of response, and relative area under the curve(AUC) according to the estrous cycle.
RESULTS
Reproducible frequency dependent increases in vaginal blood flow were observed in response to PNS. Relative peak flow, time to peak, duration of response and relative AUC were slightly greater in proestrus and estrus groups(relatively higher estradiol level, n=17) than those in metestrus and diestrus groups(relatively lower estradiol level, n=13). However, these differences were not statistically significant.
CONCLUSIONS
Our data suggest that the rat is a useful and reliable animal model for investigating the vaginal arousal response. In addition, the estrous cycle of the animal does not seem to be an important confounding factor in this animal model.