title: Centrally acting leptin induces a resuscitating effect in haemorrhagic shock in rats.
abstract: Centrally acting leptin induces the activation of the sympathetic nervous system with a pressor effect in normotensive rats. The purpose of the study was to examine central leptin-evoked action in critical haemorrhagic hypotension. In anaesthetized male Wistar rats subjected for irreversible haemorrhagic shock with mean arterial pressure (MAP) 20-25 mmHg haemodynamic parameters and plasma concentrations of adrenaline and noradrenaline were measured. Leptin given intracerebroventricularly (20 μg) evoked long-lasting rises in MAP and heart rate (HR), with a subsequent increase in renal, mesenteric and hindquarters blood flows and a 100% survival at 2 h. MAP and peripheral blood flow changes were inhibited by a pre-treatment with α(1)- and α(2)-adrenoceptor antagonists prazosin (0.5 mg/kg) and yohimbine (1 mg/kg), while β-adrenoceptor antagonist propranolol (1 mg/kg) blocked leptin-induced HR changes, without influence on MAP, peripheral blood flows and survival. Twenty min after leptin treatment, there were higher plasma concentrations of noradrenaline, but not adrenaline, in comparison with the saline-treated control group. In conclusion, centrally acting leptin induces a long-lasting pressor effect with an improvement in the survival rate in haemorrhage-shocked rats. The effect may be associated with the activation of the sympathetic nervous system.
authors.affiliation: Department of Basic Medical Sciences, Medical University of Silesia, Piekarska 18, 41-902 Bytom, Poland. jjochem@poczta.onet.pl
authors.forename: Jerzy
authors.initials: J
authors.lastname: Jochem
authors.forename: Zbigniew
authors.initials: Z
authors.lastname: Kalarus
authors.forename: Luca
authors.initials: L
authors.lastname: Spaccapelo
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Canalini
authors.forename: Alessandra
authors.initials: A
authors.lastname: Ottani
authors.forename: Daniela
authors.initials: D
authors.lastname: Giuliani
authors.forename: Salvatore
authors.initials: S
authors.lastname: Guarini
mesh_terms: D000818:Animals; D006339:Heart Rate / Q000187:drug effects; D007022:Hypotension / Q000503:physiopathology; D020738:Leptin / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use*; D008297:Male; D009638:Norepinephrine / Q000097:blood; D051381:Rats; D017208:Rats, Wistar; D012771:Shock, Hemorrhagic / Q000188:drug therapy* / Q000503:physiopathology / Q000601:surgery; D015996:Survival Rate
chemical_list: D020738:Leptin; D009638:Norepinephrine