Effets d'une anesthésie générale à l'éther ou à la kétamine sur les rythmes circadiens de la température corporelle, de la fréquence cardiaque et de l'activité locomotrice chez le rat

The aim of this study was to evaluate the effect of anaesthesia (ether or ketamine) on daily rhythms of temperature (T), heart rate (H) and locomotor activity (A) in unrestrained rats by using implanted radio-telemetry transmitters. T, H and A were measured every 10 minutes and analysed using Cosinor. Six male Wistar rats were anaesthetized for about 50 minutes either by ketamine or ether in a 3 by 3 cross-over design. Mesors, amplitudes and acrophases of T, H and A were calculated three days before, the day of anaesthesia as well as the three following days, expressed as means ± SEM and compared by ANOVA. Our results showed alterations of acrophases, mesors and amplitudes of the daily rhythms of T, H and A on the day of ketamine anaesthesia while regarding ether anaesthesia only amplitude of T and H and acrophase of A were modified on the day of anaesthesia. Furthermore, a non-detection of T, H and A daily rhythms after surgical implantation, which was not observed after injection of either ether or ketamine alone. Almost 10 days were needed to detect a significant daily rhythm for T, H and A.