HISTOCHEMICAL DISTRIBUTION OF CHOLINESTERASES IN THE TESTIS, EPIDIDYMIS AND VAS DEFERENS OF THE RAT.

Abstract

AbstractTestes, epididymides, and vasa deferentia of rats were examined for the distribution of cholinesterases using the Koelle thiocholine method. Activity of these enzymes was studied from birth to maturity. Acetylcholinesterase appeared first in Schwann cells of the nerve plexus of the vas deferens and auda epididymidis at birth. Epithelial cell pseudo‐cholinesterase appears in the vas deferens at four days, and an adult distribution is attained at thirty days. Testis, rete testis, ductuli efferentes, and upper caput epididymidis are mainly negative for cholinesterases. In the remainder of the epididymis, three zones of intense epithelial cell reactivity are preceded by regions of lesser intensity. Smooth muscles of the epididymis are negative, but the vas deferens musculature reacts for pseudo‐cholinesterase. The nerve plexus is positive for both acetyl‐ and pseudo‐cholinesterase, and is confined to the corpus and cauda epididymidis and vas deferens. The increasing density of the enzyme‐positive nerves, and the cholinesterase reaction of the musculature distally suggests a probable inhibitory role in the regulation of smooth muscle function in these regions under normal conditions. The absence of an enzyme‐positive innervation and the presence of an enzyme‐negative musculature of the caput is correlated with an active rhythmic contractility in this region, which gradually disappears distally.