The distribution of autonomic nerves in the musculature of the rat vas deferens. A light and electron microscope investigation

Light microscope histochemical techniques and electron microscopy were used to study the distribution of autonomic nerves in the muscle coat of the rat vas deferens. Numerous fluorescent catecholamine containing nerves were demonstrated throughout the length of the vas; muscle cells on its inner aspect were particularly well innervated. This distribution differed markedly from that of acetylcholinesterase containing fibres, the majority of which occurred at the testicular end. Few similar nerves were observed in the muscle coat further towards the urethral end of the vas. The distribution of fluorescent and acetylcholinesterase‐positive nerves correlated well with the arrangement of adrenergic and non‐adrenergic terminal regions identified on permanganate fixed sections using the electron microscope. Their distribution was endorsed using 6‐hydroxydopamine to selectively damage adrenergic terminals. Adrenergic nerve terminals were frequently observed in isolation amongst smooth muscle cells while the non‐adrenergic type were almost invariably associated with other axons. The significance of these observations is discussed.