An inhibitory effect of atropine on responses of the vas deferens of the mouse to field stimulation.

1 Atropine is shown to impair responses of the vas deferens of the mouse to field stimulation by acting at a site proximal to the smooth muscle cells. 2 The inhibitory effect of atropine is prevented by desmethylimipramine and reversed by dexamphetamine, and appears similar to the adrenergic-neurone blockade of guanethidine. 3 Electronmicroscopical studies show the presence in vas of presumptive noradrenergic axons which have acetylcholinesterase reaction product associated with their axolemmae. 4 These results are discussed in relation to the controversial hypothesis of a 'cholinergic link' in noradrenergic transmission.