Effect of theaflavin on intracellular free calcium concentration in rat ventricular myocytes
- VernacularTitle:茶黄素对大鼠心室肌细胞内游离钙浓度的影响
- Author:
Huijie MA
;
Huijuan MA
;
Qian LI
;
Fang YUAN
;
Yi ZHANG
- Publication Type:Journal Article
- Keywords:
theaflavin;
fluorescence intensity;
myocytes;
intracellular calcium;
confocal microscopy;
voltage-dependent Ca2+ channel
- From:
Chinese Pharmacological Bulletin
2003;0(08):-
- CountryChina
- Language:Chinese
-
Abstract:
Aim To observe the effects of theaflavin on intracellular calcium concentration(i) level in rat ventricular myocytes and discuss the possible mechanisms.Methods The effects of theaflavin oni were investigated in rat ventricular myocytes.i was detected by laser confocal microscopy and represented by relative fluorescent intensity(FI-FI0)/FI0,%;FI0:control;FI:administration of drugs).Results ① Theaflavin(10,20,40 ?mol?L-1) had no effect on the i of ventricular myocytes in normal Tyrode′s solution.However,it reduced the i of ventricular myocytes in simulated ischemia solution in a concentration-dependent manner.② Pretreatment with Bay k8644(0.5 ?mol?L-1) mostly abolished the effects of theaflavin(20 ?mol?L-1) in simulated ischemia solution.③ Theaflavin(20 ?mol?L-1) markedly inhibited the low concentration of ryanodine-induced i increase in Ca2+-free Tyrode′s solution.④ When the propagating waves of elevated i(Ca2+ waves) were produced by increasing extracellular Ca2+ concentration from 1 mmol?L-1to 10 mmol?L-1,theaflavin(20 ?mol?L-1) could block the propagating waves of elevated i(Ca2+ waves),reduce the frequency and duration of propagating waves,and reduce i as well.Conclusion Theaflavin may reduce the i in isolated rat ventricular myocytes via inhibiting Ca2+ influx by voltage-dependent Ca2+ channel and alleviating Ca2+ release from sarcoplasmic reticulum(SR).
