The Effects of Sympathectomy by 6-Hydroxydopamine and Pretreatment of Testosterone on the Contractility of the Vas Deferens in Rats

Oh, Jang Min; Lee, Dong Hwan

Abstract

PURPOSE: The chemical sympathectomy is now widely performed procedure for vascular diseases of extremities. But it has been reported that this procedure may produce ejaculatory failure in men. We investigated the changes of the contractility of the vas deferens after chemical sympathectomy by 6-hydroxydopamine, and whether these changes can be recovered by the pretreatment of testosterone.
MATERIALS AND METHODS
The rats were divided into 5 groups, which were 1) control 2) 6-hydroxydopamine 100mg group 3) 6-hydroxydopamine 100mg + testosterone100mg group 4) 6-hydroxydopamine 200mg group 5) 6-hydroxydopamine 200mg + testosterone 100mg group. 6-hydroxydopamine was injected intraperitoneally in each group at day 1, 3, 5 and killed at day 6. Testosterone was Injected intraperitoneally 30 minutes prior to 6-hydroxydopamine injection at day 1 . The vas deferns was quickly dissected out and the contractilities by electrical field stimulation, phenylephrine, acetylcholine and KCI were compared with control group.
RESULTS
In prostatic vas, the phasic contractions were reduced only in 6-hydroxy- dopamine 200mg group and recovered incompletely by testosterone. Tonic contractions in prostatic vats were reduced in 6-hydroxydopamine looms group and 6-hydroxydopamine 100mg+testosterone 100mg group at 4, 8, 16Hz field stimulation and there was no significant difference between the two groups. The contractilies in 6-hydroxydopamine 200mg group and 6-hydroxydopamine 200mg+testosterone 100mg group were reduced at all frequencies, and testosterone pretreatment group showed slightly recovered contractility at 32, 64Hz, but less than those of control. In epididymal vas, the phasic and tonic contractions were reduced in all groups compared to control except in 6-hydroxydopamine 100mg+testosterone looms group at 32, 64Hz. The effects of 6-hydroxydopamine on phenylephrine or acetylcholine induced contraction showed supersensitivity, however, testosterone pretreatments had no effects on their supersensitivity. In the response to KCI, there was no difference in all the experimental groups.
CONCLUSIONS
It seems that chemical sympathectomy results in decreased contraction of the vas deferens, which is the main cause of ejaculatory failure. Although there is some protective effect by testosterone pretreatment, but it is thought that it is not so sufficient to prevent ejaculatory failure. But we suggest that there are possibilities of protective effect of testosterone by altering the dose and time of administration.