Influence of Chronic Lead Intoxication on Functional Characteristics and Isoform Composition of Left Ventricular Myosin in Rats
The chronic lead intoxication was induced by the administration of intraperitoneal injections of lead acetate to outbred rats 3 times a week for 5 weeks. Using an <i>in vitro</i> motility assay, it was shown that lead intoxication causes changes in actin-myosin interaction <i>in vitro</i>, in particular, a decrease in the maximum sliding velocity of native thin filaments along myosin isolated from the myocardium of the left ventricle of the rat heart. No statistically significant changes were found in the calcium sensitivity and cooperativity of the “<i>p</i>Ca-velocity” curve, the characteristics of the fraction of motile filaments and isometric force. Using electrophoretic separation of proteins, a shift in the ratio of myosin heavy chains towards β-chains with slower ATPase activity was found.