acid-base balance; chronobiology; electrophysiology of the heart; zoletil

Zoletil anaesthesia does not affect vital functions; however, there is no literature evidence regarding the effect of zoletil anaesthesia on the circadian rhythm(s) of vital functions. The aims of this study, with respect to dependence on the light-dark (LD) cycle under in vivo conditions in spontaneously breathing zoletil-anaesthetized rats, were to assess ECG parameters that may to predict development of ventricular arrhythmias and to assess arterial acid-base balance, which have the direct impact on the heart electrophysiology. The experiment was performed using zoletil-anaesthetized (30mg/kg, i.p) female Wistar rats after adaptation to LD cycle (12h:12h). LD differences were found in heart rate, rectal temperature, electrophysiological myocardial parameters and acid-base balance.