Sympathetic denervation of the smooth muscle of the vas deferens.

1. The post-ganglionic nerve fibres to the vas deferens of the guinea-pig and rat were interrupted in vivo by stripping one vas deferens of its serous coat; the other vas deferens was left intact as a control.2. Four to eight days later the stripped vas deferens did not contract in response to electrical transmural stimulation in vitro at 0.1 msec pulse duration. Pulses of 1.0 msec duration produced small contractions which were not abolished by local anaesthetic or adrenergic neurone-blocking drugs.3. Log dose-response curves to noradrenaline were, for stripped vasa deferentia, to the left of those for control vasa. The increase in sensitivity to noradrenaline at 8 days was about sixteenfold for rat vasa and about tenfold for guinea-pig vasa. Tyramine did not contract stripped vasa from guinea-pigs or rats.4. The noradrenaline and adrenaline content of guinea-pig and rat vasa was greatly reduced or abolished 8 days after the stripping operation.5. Fluorescent nerve terminals were usually absent when transverse sections of stripped vasa were examined by fluorescence microscopy after treatment by the formaldehyde condensation method for demonstrating catecholamines.6. It is concluded that post-ganglionic sympathetic denervation is achieved by stripping the vas deferens in vivo of its serous coat and mesenteric attachments.