Premium
Suppressive effects of somatostatin in dog Purkinje fibres
Author(s) -
Lin ChengI,
Su MeiTsu,
Luk HsiangNing,
Wu HsuehLing
Publication year - 1988
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 - 10.1111/j.1476-5381.1988.tb11421.x
Subject(s) - purkinje fibers , somatostatin , endocrinology , biophysics , calcium , medicine , chemistry , membrane potential , purkinje cell , electrophysiology , cerebellum , biology
1 The effects of somatostatin (SS, 1 n m ‐3 μ m ) on the electrical and mechanical activities of isolated Purkinje fibres of the dog were studied. 2 In most Purkinje fibres driven electrically in normal [K] o Tyrode solution, SS decreased the force of contraction slightly and had very little effect on the fast response action potential. However, in sensitive fibres SS induced a moderate reduction of action potential duration and contractile force in normal [K] o and depressed the slow response action potentials in high [K] o . 3 In spontaneously beating Purkinje fibres, SS decreased the regular rhythms slightly but abolished bursts of fast rhythms at a concentration as low as 1 n m . 4 When the fibres were depolarized in the presence of 0.2 m m barium or in Na‐free solution, SS suppressed the Ca‐dependent slow response action potentials. 5 These findings suggest that SS may suppress abnormal automatic activity of dog Purkinje fibres through a reduction of transmembrane Ca influx or a modulation of intracellular calcium.