Occlusion of seminal vesicles increases sexual activity in a mouse model.

BACKGROUND: Little is known about the physiologic role of seminal vesicles beyond their fertility function. It has been suggested repeatedly that seminal vesicles have an impact on sexual activity. Although this has been investigated in various animal models, such a role has never been found.
OBJECTIVE: To assess in a novel mouse model whether occlusion of seminal vesicles affects sexual activity. DESIGN, SETTING, AND PARTICIPANTS: Adult male CD1 mice (n=77) were assigned randomly to the experimental groups: (1) seminal vesicle occlusion (SVO) (n=24), (2) seminal vesicle resection (SVR) (n=23), and (3) sham operation (SO) (n=30). Adult females were brought into estrus by the Whitten effect. After recuperation, mouse pairs were observed during sessions of 3h each. Sexual activity was analyzed separately by three observers blinded to the experimental conditions. INTERVENTION: SVO, SVR, and SO. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary end point was percentage of sessions with intromission; secondary end points were number of intromissions and latency until first intromission. A logistic regression model and the Kruskal-Wallis test were used. RESULTS AND LIMITATIONS: A total of 141 sessions for a total of 423h were analyzed. Intromission was scored in 20 of 42 sessions (48%) with SVO mice, a significantly higher rate than the 8 of 39 sessions (21%) with SVR mice (p=0.001) and 18 of 60 sessions (30%) with SO mice (p=0.004). Secondary end points were comparable in all three groups (p=0.303 and 0.450, respectively).
CONCLUSIONS: Males with SVO were significantly more often sexually active than males undergoing SVR or SO. This suggests that occluded, and thus engorged, seminal vesicles increase sex drive in male mice. Since the potential clinical benefit might be highly relevant, further studies should confirm these promising results and investigate the potential application in men.