title: Systemic and regional hemodynamic changes during endotoxin or platelet activating factor (PAF)-induced shock in rats.
abstract: To evaluate the role of platelet activating factor (PAF) during endotoxin shock, we compared its effects with those of endotoxin. We measured arterial pressure (MAP), heart rate (HR), cardiac output (CO; thermodilution), arterial lactate (Calact), organ blood flow (radioactive microspheres), and organ vascular resistance in four groups of anesthetized (pentobarbital) male Wistar rats (n = 7 per group), infused from t = 0 to t = 60 min with saline (group C: time matched control), endotoxin Escherichia coli O127:B8, 8 mg.kg-1 (group E), a "low PAF dose" (1 microgram.kg-1) to cause the same decrease in MAP as in group E (group PL), or a "high PAF dose" (3 micrograms.kg-1) to cause the same decrease in CO as in group E (group PH). At t = 60 min, MAP had decreased by 33% in E and PL, and by 55% in PH group. CO had decreased by 41% in the E and PH group. Calact had increased in the E and PH group by 300 and 200%, respectively. In the E, PL and PH group, coronary vascular resistance decreased. In the splanchnic organs, endotoxin caused a decrease in blood flow due to vasoconstriction, whereas PAF (both concentrations) caused vasodilation (except for spleen). Renal vascular resistance decreased (P < 0.05) in the PL group. In all groups, vascular resistance had increased (P < 0.05) in skin, and not changed in skeletal muscle (P < 0.05). Thus, hemodynamic changes after PAF infusion were partially similar to those after endotoxin infusion (coronary vasodilation and vasoconstriction in spleen and skin).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Laboratory for Physiology, Free University Hospital, Free University, Amsterdam, The Netherlands.
authors.forename: M F
authors.initials: MF
authors.lastname: Mulder
authors.forename: A A
authors.initials: AA
authors.lastname: van Lambalgen
authors.forename: A A
authors.initials: AA
authors.lastname: van Kraats
authors.forename: P G
authors.initials: PG
authors.lastname: Scheffer
authors.forename: A A
authors.initials: AA
authors.lastname: Bouman
authors.forename: G C
authors.initials: GC
authors.lastname: van den Bos
authors.forename: L G
authors.initials: LG
authors.lastname: Thijs
mesh_terms: D000818:Animals; D004224:Diterpenes; D004731:Endotoxins / Q000633:toxicity*; D046934:Ginkgolides; D006439:Hemodynamics / Q000187:drug effects*; D007783:Lactones / Q000494:pharmacology; D008297:Male; D010972:Platelet Activating Factor / Q000032:analysis / Q000494:pharmacology* / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D012039:Regional Blood Flow / Q000187:drug effects; D012772:Shock, Septic / Q000503:physiopathology*; D014655:Vascular Resistance / Q000187:drug effects
chemical_list: D004224:Diterpenes; D004731:Endotoxins; D046934:Ginkgolides; D007783:Lactones; D010972:Platelet Activating Factor; C045856:ginkgolide B