The in vitro and in vivo effects of vinca alkaloids on the noradrenergic innervation of the vas deferens.

The effects of Vinca alkaloids on the vas deferens have been examined after in vitro and in vivo administration. In the organ bath, vinblastine (1 X 10-4M for 4 hr) caused an increase in sensitivity to noradrenaline and biochemical, histochemical and ulstrastructural signs of noradrenaline depletion from the nerves supplying the outer longitudinal muscle layer. After intravenous injection of Vinca alkaloids the nerve fibres seemed less affected. It is concluded that the apparent resistance to the drugs in vivo is largely due to low tissue perfusion.