title: Autonomic nervous system under ketamine/ xylazine and pentobarbital anaesthesia in a Wistar rat model: a chronobiological view.
abstract: The aim of the present study was to determine the effect of ketamine/ xylazine and pentobarbital anaesthesia on heart rate variability as a marker of autonomic nervous system activity. The experiments were performed in ketamine/ xylazine (10 mg/kg/15 mg/kg) and pentobarbital (40 mg/kg, i.p.) anaesthetized female Wistar rats, after adaptation to a light-dark cycle of 12 hours light: 12 hours dark. Heart rate variability parameters (RR interval, power VLF (very low frequency), power LF (low frequency), power HF (high frequency) and relative powers) were evaluated during spontaneous breathing as a function of the light-dark cycle (LD cycle). Significant LD differences were found in the duration of RR intervals in ketamine/xylazine compared with pentobarbital-anaesthetized rats. Correlation analysis revealed moderate dependency between the RR interval duration and HF and LF power parameters in ketamine/xylazine anaesthesia in both light and dark parts of the cycle. In pentobarbital-anaesthetized rats, correlation analysis demonstrated a moderate dependence between RR interval duration and HF and VLF power parameters, but only in the dark part of the LD cycle. Ketamine/xylazine anaesthesia increased parasympathetic activity, and suppressed sympathetic and baroreceptor activity independently of the light-dark cycle. LD differences in RR interval duration were not eliminated. Pentobarbital anaesthesia increased parasympathetic activity, decreased sympathetic and baroreceptor activity, and eliminated LD differences in RR interval duration.
authors.affiliation: Department of Physiology, University of Ostrava, Ostrava, Czech Republic. pavolml.svorc@osu.cz
authors.forename: P
authors.initials: P
authors.lastname: Svorc
authors.forename: I
authors.initials: I
authors.lastname: Bačová
authors.forename: P
authors.initials: P
authors.lastname: Svorc
authors.forename: M
authors.initials: M
authors.lastname: Bužga
mesh_terms: D000758:Anesthesia; D000777:Anesthetics / Q000494:pharmacology*; D000818:Animals; D001341:Autonomic Nervous System / Q000187:drug effects*; D002909:Chronobiology Phenomena; D005260:Female; D007649:Ketamine / Q000494:pharmacology*; D023421:Models, Animal; D010424:Pentobarbital / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors; D014991:Xylazine / Q000494:pharmacology*
chemical_list: D000777:Anesthetics; D014991:Xylazine; D007649:Ketamine; D010424:Pentobarbital