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Cardiovascular effects of carnosine
1Department of Anesthesiology, Wake Forest University School of Medicine, Winston-Salem, NC 27157-1009, USA.
Biochemistry. Biokhimiia
|August 22, 2000
Summary
Carnosine, a naturally occurring dipeptide, significantly enhances heart muscle contractility by modulating calcium release and ryanodine receptors. This suggests carnosine is a key regulator of cardiac function.
Area of Science:
- Cardiology
- Biochemistry
- Molecular Biology
Background:
- Carnosine (beta-alanyl-L-histidine) is an endogenous dipeptide present in cells at high concentrations.
- Its precise physiological roles, particularly in cardiac function, remain largely undefined.
Purpose of the Study:
- To investigate the functional effects of carnosine on cardiac contractility.
- To elucidate the molecular mechanisms underlying carnosine's action in cardiac muscle cells.
Main Methods:
- Perfusion of isolated rat hearts with carnosine.
- Studies on chemically skinned cardiac cells.
- Direct investigation of carnosine's interaction with cardiac ryanodine receptors.
Main Results:
- Carnosine significantly increased cardiac contractility.
- Its effects were independent of histaminic, beta-adrenergic receptors, and cyclic AMP.
- Carnosine elevated myoplasmic Ca(2+) concentration.
- It directly modulated ryanodine receptor activity, increasing channel open probability and dwell time.
Conclusions:
- Carnosine acts as a direct modulator of calcium-regulated proteins in cardiac muscle.
- It plays a critical role in determining cardiac contractility and overall cardiac function.