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Capsaicin enhances the non‐adrenergic twitch response of rat vas deferens
Author(s) -
Moritoki Hideki,
Iwamoto Takeshi,
Kanaya Jun,
Ishida Yukio,
Ando Kenshi,
Kitagawa Kouki
Publication year - 1987
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1987.tb11344.x
Subject(s) - vas deferens , prazosin , medicine , endocrinology , stimulation , adrenergic , chemistry , reserpine , desensitization (medicine) , capsaicin , biology , receptor , antagonist
1 Capsaicin (Cap) enhanced the twitch response of the epididymal and prostatic portions of rat vas deferens induced by field stimulation at 0.1 Hz. The effect of Cap was reproducible and showed no desensitization. 2 Prazosin, and pretreatment with reserpine or Cap did not affect the potentiating effect of Cap, whereas pretreatment with 6‐hydroxydopamine abolished the action of Cap. 3 Cap tended to attenuate the contractions induced by noradrenaline, tyramine and ATP. 4 Like Cap, substance K and substance P augmented the twitch response without causing desensitization, but their effects differed somewhat from that of Cap. Calcitonin gene‐related peptide inhibited the twitch response. 5 These results suggest that Cap enhances a stimulation‐induced, prazosin‐resistant non‐adrenergic twitch response of rat vas deferens through an as yet undefined prejunctional mechanism. This mechanism is possibly mediated by some peptide released in response to Cap from sensory neurones, which in turn acts on sympathetic nerves and increases stimulation‐induced release of a mediator or co‐transmitter responsible for the non‐adrenergic twitch response. However, the possibility that Cap has a direct action on sympathetic nerves cannot be ruled out.