Premium
Effects of heptanol on the neurogenic and myogenic contractions of the guinea‐pig vas deferens
Author(s) -
Venkateswarlu K,
Dange Sumedha Y,
Manchanda Rohit
Publication year - 1999
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1038/sj.bjp.0702307
Subject(s) - heptanol , vas deferens , prazosin , gap junction , medicine , endocrinology , stimulation , muscle contraction , contraction (grammar) , electrophysiology , chemistry , excitatory postsynaptic potential , biology , intracellular , inhibitory postsynaptic potential , receptor , antagonist , biochemistry
The effects of the putative gap junction uncoupler, 1‐heptanol, on the neurogenic and myogenic contractile responses of guinea‐pig vas deferens were studied in vitro. Superfusion of 2.0 m M heptanol for 20–30 min produced the following reversible changes in the biphasic neurogenic contractile response (8 trials): (i) suppression of both phases; (ii) delayed development of both the first as well as the second phase, accompanied by complete temporal separation of the two phases; (iii) prominent oscillations of force during the second (noradrenergic) phase only. To eliminate prejunctional effects of heptanol, myogenic contractions were evoked by field stimulation of the vas in the presence of suramin (200 μ M ) and prazosin (1 μ M ). Heptanol (2.0 m M ) abolished these contractions reversibly. These results show that (i) heptanol inhibits both excitatory junction potential (EJP)‐dependent and non EJP‐dependent contractions of the vas ; (ii) a postjunctional site of action of heptanol, probably intercellular uncoupling of smooth muscle cells, contributes to the inhibition of contraction.British Journal of Pharmacology (1999) 126 , 227–234; doi: 10.1038/sj.bjp.0702307