ISSN:
1432-2013
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract Whole cell currents were recorded in single myocytes dissociated from guinea-pig ventricles, and caged compounds were loaded intracellularly through the patch electrodes. Flash photolysis of caged cyclic GMP (cGMP) increased the amplitudes of both catecholamine-induced Cl− (ICl) and Ca2+ currents (ICa) which were pre-activated by submaximum doses of isoprenaline. Transient activation of ICl by photo-release of cyclic AMP (cAMP) showed a half decay time (t1/2) of 16.7±1.4 sec (mean±S.E.M., n=14). This decay was markedly delayed by inhibiting phosphodiesterases using 3-isobutyl-1-methyl-xanthine (IBMX). The intracellular application of cGMP (10–50μ M)also prolonged the decay of the ICl response to caged cAMP (t1/2=38.0±7.1 sec, n=12). These findings strongly support the hypothesis that cGMP facilitates theβ-adrenergic response of ionic currents through the inhibition of phosphodiesterase in mammalian cardiac myocytes.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00374920
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