Effects of genistein on intracellular free-calcium concentration in guinea pig ventricular myocytes.
- Author:
En-Sheng JI
1
;
Chuan WANG
;
Rui-Rong HE
Author Information
1. Departments of Physiology, Institute of Basic Medicine, Hebei Medical University, Shijiazhuang 050017, China.
- Publication Type:Journal Article
- MeSH:
3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester;
pharmacology;
Animals;
Calcium;
metabolism;
Calcium Channel Blockers;
pharmacology;
Calcium Channels, L-Type;
Genistein;
pharmacology;
Guinea Pigs;
Heart Ventricles;
Male;
Microscopy, Confocal;
Myocytes, Cardiac;
cytology;
metabolism;
ultrastructure;
Protein Tyrosine Phosphatases;
antagonists & inhibitors;
Sarcoplasmic Reticulum;
metabolism;
Vanadates;
pharmacology
- From:
Acta Physiologica Sinica
2004;56(2):204-209
- CountryChina
- Language:English
-
Abstract:
The effects of genistein (GST) on intracellular calcium concentration ([Ca(2+)](i)) were investigated in guinea pig ventricular myocytes. [Ca(2+)](i) was detected by confocal microscopy and represented by relative fluorescent intensity (FI-F(0)) /FI(0), %). The results showed that GST (10-40 micromol/L) reduced [Ca(2+)](i) in normal Tyrode's solution, Ca(2+)-free Tyrode's solution and normal Tyrode's solution containing 3 mmol/L EGTA in a concentration-dependent manner. The effects of GST on [Ca(2+)](i) in normal Tyrode's solution were partially inhibited by pretreatment with sodium orthovanadate, a potent inhibitor of protein tyrosine phosphatase, or L-type Ca(2+) channel agonist Bay K8644. GST also markedly inhibited the ryanodine-induced [Ca(2+)](i) responses in Ca(2+)-free Tyrode's solution. When Ca(2+) waves were produced by increasing extracellular Ca(2+) concentration from 1 to 10 mmol/L, GST (40 micromol/L) could block the propagating waves of elevated [Ca(2+)](i), and reduce the velocity and duration of propagating waves. These results suggest that GST may reduce the [Ca(2+)](i) in isolated guinea pig ventricular myocytes. The inhibition of voltage-dependent Ca(2+) channel, tyrosine kinase inhibition, and alleviation of Ca(2+) release from SR are possibly involved in the GST effect.
