Electrophysiological effects of hydrogen sulfide on guinea pig papillary muscles in vitro.
Sheng Li Xue Bao
; 59(2): 215-20, 2007 Apr 25.
Article
em En
| MEDLINE
| ID: mdl-17437046
ABSTRACT
The cardiac electrophysiological effects of hydrogen sulfide (H2S) were examined in guinea pig papillary muscles in vitro using intracellular microelectrode technique. The results obtained were as follows (1) the duration of action potential (APD) in the normal papillary muscles was decreased by NaHS (H(2)S donor, 50, 100, 200 micromol/L) in a concentration-dependent manner; (2) in partially depolarized papillary muscles, 100 micromol/L NaHS not only reduced APD, but also decreased the amplitude of action potential (APA), overshoot (OS) and maximal velocity of depolarization at phase 0 (V(max)); (3) pretreatment with ATP-sensitive K(+) (K(ATP)) channel blocker glibenclamide (20 micromol/L) partially blocked the effects of NaHS (100 micromol/L); (4) pretreatment with L-type Ca(2+) channel agonist Bay K8644 (0.5 micromol/L) also partially blocked the effects of NaHS (100 micromol/L); (5) pretreatment with Ca(2+)-free Krebs-Henseleit solution containing glibenclamide (20 micromol/L) completely blocked the effects of NaHS (100 micromol/L); (6) APD in the normal papillary muscles was increased by DL-propargylglycine (PPG, an inhibitor of cystathionine gamma-lyase, 200 micromol/L). All these results suggest that the electrophysiological effects of H(2)S on papillary muscles in our study are due to an increase in potassium efflux through the opening of K(ATP) channels and a decrease in calcium influx. Endogenous H(2)S may act as an important regulator in electrophysiological characters in papillary muscles.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Músculos Papilares
/
Potenciais de Ação
/
Sulfeto de Hidrogênio
Limite:
Animals
Idioma:
En
Revista:
Sheng Li Xue Bao
Ano de publicação:
2007
Tipo de documento:
Article
País de afiliação:
China