Effect of hyperhomocysteinemia on rat cardiac sarcoplasmic reticulum.
Zuzana TatarkovaMaria BencurovaJan LehotskyPeter RacayMonika Kmetova SivonovaDusan DobrotaPeter KaplanPublished in: Molecular and cellular biochemistry (2022)
Increased concentration of plasma homocysteine (Hcy) is an independent risk factor of cardiovascular disease, yet the mechanism by which hyperhomocysteinemia (HHcy) causes cardiac dysfunction is largely unknown. The aim of present study was to investigate the contribution of sarcoplasmic reticulum to impaired cardiac contractile function in HHCy. HHcy-induced by subcutaneous injection of Hcy (0.45 μmol/g of body weight) twice a day for a period of 2 weeks resulted in significant decrease in developed left ventricular pressure and maximum rate of ventricular relaxation. Our results show that abundances of SR Ca 2+ -handling proteins, Ca 2+ -ATPase (SERCA2), calsequestrin and histidine-rich calcium-binding protein are significantly reduced while the content of phospholamban is unchanged. Moreover, we found that increased PLN:SERCA2 ratio results in the inhibition of SERCA2 activity at low free Ca 2+ concentrations. We further discovered that HHcy is not associated with increased oxidative stress in SR. Taken together, these findings suggest that disturbances in SR Ca 2+ handling, caused by altered protein contents but not oxidative damage, may contribute to impaired cardiac contractility in HHcy.
Keyphrases
- left ventricular
- oxidative stress
- body weight
- cardiovascular disease
- binding protein
- heart failure
- hypertrophic cardiomyopathy
- cardiac resynchronization therapy
- acute myocardial infarction
- left atrial
- risk factors
- mitral valve
- type diabetes
- aortic stenosis
- metabolic syndrome
- dna damage
- acute coronary syndrome
- amino acid
- ischemia reperfusion injury
- gestational age
- small molecule
- endoplasmic reticulum stress
- catheter ablation