RESISTANCE OF MECHANICAL AND ELECTRICAL RESPONSES TO HYPOGASTRIC NERVE STIMULATION TO α-BLOCKING AGENTS IN GUINEA-PIG VAS DEFERENS

摘要

References(22) Cited-By(1) In spite of the availability of much evidence showing the sympathetic nature of the hypogastric nerve innervating the guinea-pig vas deferens (1-8) a persistent resistance of the contractile response to hypogastric nerve stimulation to various adrenergic α-blocking agents in vitro has still remained unexplained. Boyd et al. (9) and Ohlin and Strömband (10) observed that the contractile response to hypogastric nerve stimulation was not depressed by moderate doses of various α-blocking agents but rather potentiated owing to their anti-cholinesterase activity. Burnstock and Holman (8) have also demonstrated that the junction potentials in response to hypogastric nerve stimulation had a considerable resistance to the α-blocking agents in the guinea-pig vas deferens in vitro. The present study was, therefore, designed to reappraise the well known in vitro resistancy, of mechanical and electrical responses of guinea-pig vas deferens to hypogastric nerve stimulation to α-blocking agents, using an in vivo preparation, in which the intravenously administered drugs would reach the receptor sites through the blood stream with active pressure.