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The innervation of sheep mesenteric veins
Author(s) -
Holman Mollie E.,
McLean A.
Publication year - 1967
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.1967.sp008192
Subject(s) - guanethidine , hexamethonium , tetrodotoxin , adventitia , stimulation , acetylcholine , anatomy , excitatory postsynaptic potential , contraction (grammar) , chemistry , medicine , endocrinology , biology , receptor
1. An isolated preparation of sheep mesenteric vein is described from which contractions of the longitudinal smooth muscle of the adventitia have been recorded in response to stimulation of intramural and periarterial nerves. 2. The preparation did not respond to single stimuli but the relation between amplitude of response and frequency of stimulation was characteristic of that described for other smooth muscles innervated by sympathetic nerves. 3. Responses were blocked by tetrodotoxin, guanethidine, and by a number of α‐receptor blocking drugs. Responses to peri‐arterial stimulation were unaffected by hexamethonium. It was concluded that the longitudinal smooth muscle is supplied with post‐ganglionic noradrenergic motor nerves and the presence of such fibres in the adventitia was confirmed by fluorescence microscopy. 4. Acetylcholine also caused contractions. Although a direct excitatory action on the smooth muscle could not be excluded, results suggest that acetylcholine may release noradrenaline from the axons of the sympathetic ground plexus.