title: Vagally mediated sympathoexcitation and central depression by desflurane in rabbits.
abstract: The effects of desflurane on renal sympathetic nerve activity (RSNA) were studied in intact or vagotomized anaesthetized rabbits with initial concentrations of 4.5-18%, subsequently equilibrated to end-tidal concentrations from 3%, 6%, 9% and 12% each for 20 min allowing sympathetic activity to stabilize. In intact animals, immediate transient increases in mean sympathetic activity from 27% to 63% were closely related to initial concentrations from 4.5% to 18%. During subsequent equilibration this remained elevated by 25-30% up to 6%, returned to control at 9% and fell by 33% at 12%. Bilateral vagotomy abolished sympathoexcitation apart from small increases in sympathetic activity, for example 14% at 4.5% (P < 0.05). We conclude that increases in inspired desflurane concentrations evoked rapid transient vagally mediated reflex sympathoexcitation with a small extra-vagal contribution. Central depression of sympathetic activity started at 6% and was 33% below baseline at 12%.
authors.affiliation: Department of Anaesthetics and Intensive Care, Imperial College School of Medicine, Hammersmith Hospital, London, UK.
authors.forename: C K
authors.initials: CK
authors.lastname: Pac-Soo
authors.forename: C
authors.initials: C
authors.lastname: Wang
authors.forename: D
authors.initials: D
authors.lastname: Ma
authors.forename: M K
authors.initials: MK
authors.lastname: Chakrabarti
authors.forename: J G
authors.initials: JG
authors.lastname: Whitwam
mesh_terms: D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D000077335:Desflurane; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D007530:Isoflurane / Q000031:analogs & derivatives* / Q000494:pharmacology; D007668:Kidney / Q000294:innervation; D008297:Male; D011817:Rabbits; D013564:Sympathetic Nervous System / Q000187:drug effects* / Q000502:physiology; D014628:Vagotomy; D014630:Vagus Nerve / Q000187:drug effects* / Q000502:physiology
chemical_list: D018685:Anesthetics, Inhalation; D000077335:Desflurane; D007530:Isoflurane