Effect of acidosis on Ca2+ sensitivity of skinned cardiac muscle with troponin C exchange Implications for myocardial ischemia

FEBS Letters

Babu, Árvind¹  Gulati, Jagdish¹ 

[1] Departments of Medicine and Physiology/Biophysics, Albert Einstein College of Medicine, Bronx, NY 10461, USA

关键词: Starling's law;    Pump failure;    Contractility;    Activation;    Regulation;    (Vertebrate muscle);   

DOI  :  10.1016/0014-5793(89)80237-6

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

By using a novel approach for the study of the effects of pH variation in skinned myocardium, the present experiments were aimed to provide new insights into the mechanism of ischemia. Ca²⁺ sensitivity is decreased by acid pH, but the effect is more than double in cardiac myofilaments than that in fast-twitch skeletal muscle fibers. With the technique of troponin C exchange in myocytes, we find here that the effect of pH is the same with cardiac or skeletal troponin C. These results rule out a direct H⁺-Ca²⁺ competition on the Ca²⁺-binding sites of troponin C as a significant mechanism of ischemia. The findings provide conclusive evidence in favor of the idea that acidosis modulates the protein-protein interactions in the regulatory complex in cardiac muscle.

【 授权许可】

Unknown