Effects of antidepressants in adrenergic neurotransmission of human vas deferens

Abstract

Objectives. To evaluate the effects of sertraline, fluoxetine, and amitriptyline on the contractile responses of the human vas deferens muscle elicited by norepinephrine, electrical field stimulation, and KCl, because the therapeutic action of antidepressants may be accompanied by sexual dysfunction related to the contractility of the vas deferens smooth muscle. Methods. Ring segments of the epididymal part of the vas deferens were taken from 32 elective vasectomies and mounted in organ baths for isometric recording of tension. We then studied the effects of sertraline, fluoxetine, and amitriptyline on the neurogenic and agonist-induced contractile responses. Results. Amitriptyline caused concentration-dependent inhibition of neurogenic and norepinephrine-induced contractions. In contrast, only the highest concentration (10 −5 M) of sertraline and fluoxetine reduced the adrenergic contractions. The dihydropyridine calcium antagonist nifedipine (10 −6 M) completely prevented the inhibitory effect of sertraline and fluoxetine on neurogenic and norepinephrine-induced contractions but did not change the inhibition caused by amitriptyline. Sertraline, fluoxetine, and amitriptyline (all at 10 −5 M) attenuated contractions elicited by KCl and reduced contractions induced by CaCl 2 in KCl-depolarized preparations. Conclusions. The results indicate that sertraline and fluoxetine inhibit vas deferens motility through inhibition of Ca 2+ entry, with no effect on the adrenergic receptors, and amitriptyline acts as an adrenoceptor antagonist and inhibitor of the entry of calcium.