Mechanisms of Vitexin Preconditioning Effects on Cultured Neonatal Rat Cardiomyocytes with Anoxia and Reoxygenation

This study was aimed at investigating the protective effect and mechanism of vitexin preconditioning (VPC) on cultured neonatal rat cardiomyocytes after anoxia and reoxygenation (A/R). An A/R model was established by using cultured neonatal rat cardiomyocytes. Cellular injury was evaluated by measuring cell viability, the releases of creatine kinase (CK), and lactate dehydrogenase (LDH). The apoptosis rate of cardiomyocytes after Anoxia/reoxygenation and the activities of extracellular signal-regulated protein kinases (ERKs) were measured. The intracellular calcium indicated by the fluorescence in cardiomyocytes was measured by the laser confocal microscope. Vitexin preconditioning (10, 30 and 100 μM) significantly enhanced the cell viability, markedly inhibited A/R-induced increases of LDH and CK release, obviously decreased the number of apoptotic cardiomyocytes and markedly decreased the fluorescence intensity value of [ Ca2+]iin cardiomyocytes. Exposure to anoxia or vitexin preconditioning significantly increased the phospho-ERK level, and the increase was markedly inhibited by PD98059, an inhibitor of the upstream kinase of ERK. These results suggest that vitexin preconditioning has a protective effect on cardiomyocytes A/R injury through the improvement of cell viability, decrease of LDH and CK release, such that the protective mechanism may relate to its ability to inhibit the cardiomyocytes apoptosis, reduce the cardiomyocytes calcium overload and increase the abundance of phosphor-ERK1/2 of the cardiomyocytes after anoxia and reoxygenation.

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Effects of endothelin-11-31 on cell viability and [Ca2+]i in cultured neonatal rat cardiomyocytes

Physiological Research ◽

10.33549/physiolres.931168 ◽

2008 ◽

pp. 373-378

Author(s):

A-J Ren ◽

X Yuan ◽

L Lin ◽

Y-X Pan ◽

Y-W Qing ◽

...

Keyword(s):

Cell Viability ◽

Cell Injury ◽

Neonatal Rat ◽

Sod Activity ◽

Rat Cardiomyocytes ◽

Continuous Increase ◽

Neonatal Rat Cardiomyocytes ◽

Eta Receptor ◽

Laser Confocal Microscope ◽

Eta Receptor Antagonist

We previously found that Endothelin-11-31 (ET-11-31) exhibited a pro-arrhythmogenic effect in isolated rat hearts. In this study, we further investigated the effects of ET-11-31 on a cell viability and observed [Ca2+]i in cultured cardiomyocytes. Cultured neonatal rat cardiomyocytes were treated with 0.1, 1, and 10 nM ET-11-31 for 24h in the presence or absence of ETA receptor antagonist (BQ123) or phosphoramidon, a NEP/ECE inhibitor. Cell injury was evaluated by supernatant lactate dehydrogenase (LDH) assay, superoxide dismutase (SOD) activity, and malondialdehyde (MDA) content. Cell viability was assessed by MTT assay. [Ca2+]i was measured with Fluo-3/AM under a laser confocal microscope. 1) ET-11-31 dose-dependently increased LDH release and decreased cell viability. 2) LDH and MDA levels were significantly elevated and SOD activity decreased after administration of 1 nM ET-11-31 for 24h, and these changes were markedly attenuated by 1 uM BQ123. 3) Exposure to 10 nM ET-11-31 caused a continuous increase in [Ca2+]i to cultured beating cardiomyocytes and termination of [Ca2+]i transient within 6 min, and this change was reversed by 1 uM BQ123 and attenuated by 0.5 mM phosphoramidon. These results suggest that ET-11-31 could cause cell injury, and that the effect of ET-11-31 on [Ca2+]i transients is mainly mediated by ETA receptor and partially attributed to the conversion of ET-11-31 to ET-11-21.

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The Inhibitory Effect of Trilinolein on Norepinephrine-Induced β-Myosin Heavy Chain Promoter Activity, Reactive Oxygen Species Generation, and Extracellular Signal-Regulated Kinase Phosphorylation in Neonatal Rat Cardiomyocytes

Journal of Biomedical Science ◽

10.1159/000075284 ◽

2004 ◽

Vol 11 (1) ◽

pp. 11-18

Author(s):

Ju-Chi Liu ◽

Paul Chan ◽

Jin-Jer Chen ◽

Horng-Mo Lee ◽

Wen-Sen Lee ◽

...

Keyword(s):

Promoter Activity ◽

Reactive Oxygen Species Generation ◽

Inhibitory Effect ◽

Neonatal Rat ◽

Oxygen Species ◽

Rat Cardiomyocytes ◽

Extracellular Signal Regulated Kinase ◽

Neonatal Rat Cardiomyocytes ◽

Extracellular Signal ◽

Kinase Phosphorylation

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Protective Effect and Mechanism of Total Flavones fromRhododendron simsiiPlanch Flower on Cultured Rat Cardiomyocytes with Anoxia and Reoxygenation

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2015/863531 ◽

2015 ◽

Vol 2015 ◽

pp. 1-10 ◽

Cited By ~ 6

Author(s):

Yi Jiao ◽

Yi-Fei Fan ◽

Yu-Ling Wang ◽

Jun-Yan Zhang ◽

Shuo Chen ◽

...

Keyword(s):

Myocardial Infarction ◽

Protective Effect ◽

Cell Viability ◽

Ischemia Reperfusion ◽

Cellular Damage ◽

Protective Mechanism ◽

Patch Clamp Technique ◽

Rat Cardiomyocytes ◽

Whole Cell Patch Clamp ◽

Myocardial Ischemia Reperfusion

Many flavonoids have cardioprotection against myocardial ischemia/reperfusion (I/R) injury. Total flavones fromRhododendron simsiiPlanch flower (TFR) can protect myocardial ischemic injuries. However, its protective mechanism is still unknown. The present study was designed to investigate the mechanism of TFR on myocardial I/R and anoxia/reoxygenation (A/R) injuries. Rat model of myocardial I/R injury was made, and myocardial infarction was determined. A/R injury was induced in cultured rat cardiomyocytes; cellular damage was evaluated by measuring cell viability, LDH and cTnT releases, and MDA content. Expressions of ROCK1and ROCK2protein were examined by Western blot analysis, and K+currents were recorded by using whole-cell patch clamp technique. TFR 20~80 mg/kg markedly reduced I/R-induced myocardial infarction. TFR 3.7~300 mg/L significantly inhibited A/R-induced reduction of cell viability, LDH and cTnT releases, and MDA production. Exposure to A/R significantly increased ROCK1and ROCK2expressions in rat cardiomyocytes, but TFR 33.3~300 mg/L obviously inhibited this increase. 300 mg/L TFR significantly augmented inward rectifier K+current and other K+currents in rat cardiomyocytes. These results indicate that TFR has a protective effect on rat cardiomyocytes A/R damage, and the protective mechanism may be engaged with the inhibition of ROCK1and ROCK2and activation of K+channels.

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