Action of vinblastine on myenteric neurones of guinea-pig ileum

Abstract

Motor activity of guinea-pig ileum in vitro was monitored by recording isometric tension. Superfusion of the serosal surface with vinblastine (22μM) increased the motility of ileum but failed to do so in the presence of local anaesthetics and also in preparations depolarised with K+-Tyrode. Atropine (6μM) or pentolinium (186 μM) reduced the motor response of vinblastine but higher concentration of atropine (60 μM) or pentolinium (930 μM) did not further attenuate the response. Strychnine (58 μM) reversibly blocked the atropine-resistant motor response elicited by vinblastine. It is concluded that vinblastine produces its motor effects by stimulating the non-cholinergic and to some extent cholinergic excitatory neurones of myenteric plexuses.