Study of the nerve endings in the vas deferens and seminal vesicle of the guinea pig

The characteristics of nerve endings present in the vas deferens and in the seminal vesicle of guinea pig have been studied by pharmacological techniques and by electron microscopy. From a pharmacological point of view it appears that cholinesterase inhibitors potentiated in both organs the contractions elicited by stimulation of the hypogastric nerve. This potentiation is present even in preparations obtained from animals pretreated with reserpine or α-methyltyrosine and is prevented or abolished by atropine. On the basis of the electron microscopic studies two types of nerve terminals, adrenergic and cholinergic, can be distinguished. The difference between the two types of nerve endings is still more evident in the organs of animals pretreated with iproniazid and DOPA. These results are interpreted as supporting the concept that the hypogastric nerve carries, to the vas deferens and to the seminal vesicle, fibers of adrenergic and cholinergic type.