Electrical and Contractile Properties of the Heart Ventricle in Response to Ambient Temperature Changes in Frog Rana temporaria

Abstract

The aim of the study was to investigate the dynamics of change in the intraventricular pressure, depolarization and repolarization processes on the ventricular epicardium (VE) in Rana temporaria in response to a rise in ambient temperature. By methods of catheterization and electrophysiological mapping the dynamics of the intraventricular pressure change, the processes of depolarization and repolarization on the epicardium of the heart ventricle in adult frogs in a temperature range from 10°C to 20°C were studied. We found that the rise in body temperature by 10°C led to increase of the maximal systolic ventricular pressure (MSVP), maximal value of the MSVP derivative and maximal rate of MSVP decline but to a decrease in dispersion of depolarization time and durations of activation-recovery intervals on the ventral and dorsal sides of VE. The role of the electrical inhomogeneity of the myocardium was shown to be a modulator performing fine adjustment to factors in the external environment of the organism.

Keywords

• intraventricular pressure
• ventricular epicardium
• depolarization
• repolarization
• temperature
• Rana temporaria