Dose dependency of subchronic lead acetate exposure on biophysical characteristics of rats’ right atrium and ventricle

The study investigated the dose-dependent effects of lead acetate on the atrial and ventricular myocardium, as well as on hematological parameters in young male rats under subchronic conditions. A decrease in systolic blood pressure, pulse pressure, and heart rate was observed. Changes in the electrocardiographic indicators manifested themselves as an increase in the length of the RR and QT intervals, as well as a shift in the contour. Data on the different effects of lead exposure on the electrical and mechanical activity of isolated strips of right atrial and ventricular myocardium are presented. It has been shown for the first time that the mechanisms of heterometric regulation of atrial myocardial contractility are more sensitive to lead intoxication than those of the ventricle. The decay time of the calcium transient in the atrial myocardium of rats with lead exposure is slower than in the control group, and it increases with the length of the myocardial strip.