Parasympathetic influence plays an independent and significant role in inducing the contraction of the seminal vesicle of the rat.
OBJECTIVE
The role of the parasympathetic pathway in seminal vesicle (SV) contraction has not been well described. The purpose of this study was to study parasympathetic effects, the dominant muscarinic receptors subtype(s), and nitric oxide (NO) effects for SV contraction.


METHODS
In vivo, SV pressure of mature male Wistar rats were recorded after electric stimulation (ES) of each pelvic nerve (PN; parasympathetic pathway) alone; bilateral PNs simultaneously, the L6 and S1 branches of the left PN; the left PN after ablation of sympathetic influence; the lesser splanchnic nerve (LSN) after ablation of parasympathetic influence; and the LSN after pretreatment of 4 muscarinic receptor antagonists or a NO donor-3-Morpholinosydnonimine (SIN-1).


RESULTS
ES to the left PN caused frequency-dependent SV contraction, with similar results after ES to the right PN and bilateral PNS. ES to the L6 branch of the left PN caused significantly greater SV response than to the S1 branch. Ablation of sympathetic influence did not affect SV response to parasympathetic stimulation and vice versa. The inhibitory effects of 4-DAMP (M3 antagonist) and atropine (nonselective muscarinic antagonist) on SV response to ES were similar and significantly greater than those of pirenzepine (M1 antagonist) and methoctramine (M2 antagonist). Pretreatment of SIN-1 partially suppressed the SV response of ES to left PN.


CONCLUSIONS
ES via the parasympathetic pathway independently induces contraction of rat SV; NO partially suppresses the SV pressure response to parasympathetic ES.
Hsieh
Ju-Ton
JT
Department of Urology, National Taiwan University Hospital, Taipei, Taiwan.
Liu
Shih-Ping
SP
Chang
Hong-Chiang
HC
Kuo
Yuh-Chen
YC
Chen
Jyh-Horng
JH
Jaw
Fu-Shan
FS
Tsai
Vincent F S
VF
D000818:Animals; D004558:Electric Stimulation; D008297:Male; D009119:Muscle Contraction; D010275:Parasympathetic Nervous System / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D012669:Seminal Vesicles / Q000294:innervation* / Q000502:physiology*