+ Site Statistics
+ Search Articles
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on Google+Follow on Google+
Follow on LinkedInFollow on LinkedIn

+ Translate

Electrophysiological effects of procaine in rabbit sino-atrial node cells

Japanese Journal of Pharmacology 40(1): 83-93

Electrophysiological effects of procaine in rabbit sino-atrial node cells

Effects of procaine (50-500 micrograms/ml) on membrane potential and currents were investigated using a two microelectrode-voltage clamp technique. Procaine reduced the action potential amplitude (APA), the maximum diastolic potential and the maximum rate of depolarization (Vmax) in a dose-dependent manner. At the same time, the action potential duration and the cycle length were prolonged. In voltage clamp experiments, procaine (50 micrograms/ml) did not affect the slow inward current (Isi), but reduced the time-dependent outward current (Ik). At concentrations higher than 100 micrograms/ml, procaine reduced both currents and the inward current activated by hyperpolarization in a dose-dependent manner. In 7 of 20 specimens, a low concentration of procaine (50 or 100 micrograms/ml) increased Isi which enhanced the Vmax and APA, but did not increase Ik. Procaine did not affect the steady-state inactivation of Isi (f infinity) and the activation of Ik (p infinity). The results suggest that the depressions of currents induced by procaine are due to a reduction in conductances of the current systems.

(PDF same-day service: $19.90)

Accession: 005349591

PMID: 2421033

DOI: 10.1254/jjp.40.83

Related references

Electrophysiological effects of alpha-adrenoceptor antagonists in rabbit sino-atrial node, cardiac Purkinje cells and papillary muscles. British Journal of Pharmacology 83(2): 419-426, 1984

Effects of lidocaine and procaine on membrane currents of rabbit sino atrial node cell. Japanese Journal of Pharmacology 33(SUPPL): 73P, 1983

Rabbit sino-atrial node cells: isolation and electrophysiological properties. Journal of Physiology 428: 405-424, 1990

Electrophysiological study of alinidine in voltage clamped rabbit sino-atrial node cells. European Journal of Pharmacology 121(2): 211-219, 1986

An electrophysiological study of amiloride on sino-atrial node cells and ventricular muscle of rabbit and dog. Naunyn-Schmiedeberg's Archives of Pharmacology 333(1): 83-90, 1986

On electrophysiological response to phorbol esters which stimulate protein kinase c in rabbit sino atrial node cells. Naunyn-Schmiedeberg's Archives of Pharmacology 337(3): 308-315, 1988

Electrophysiological actions of calcium ionophores in rabbit sino atrial sa node cells and canine purkinje fibers. Japanese Journal of Pharmacology 43(SUPPL): 101P, 1987

Electrophysiological effects of FK664, a new cardiotonic agent, on preparations from guinea pig ventricle and from rabbit sino-atrial node. Cardiovascular Research 23(5): 369-377, 1989

Electrophysiological effects of S 16257, a novel sino-atrial node modulator, on rabbit and guinea-pig cardiac preparations: Comparison with UL-FS 49. British Journal of Pharmacology 112(1): 37-42, 1994

Morphological and electrophysiological changes induced by calcium ionophores (A23187 and X-537A) in spontaneously beating rabbit sino-atrial node cells. General Pharmacology 24(1): 49-57, 1993