title: Vascular alpha-adrenoceptor blockade by E. coli endotoxin in the rat.
abstract: It has been previously shown that Escherichia coli endotoxin (ENDO) reduces the pressor effect of phenylephrine. This work attempted to define precisely the involvement of vascular alpha-adrenoceptors in this action. The dose-response curves of three alpha-agonists noradrenaline, St 587 and B-HT 933 in pithed rats were shifted rightwards by pretreatment (i.v. injection of 10 and 100 micrograms/kg) with ENDO. ENDO 10 and 30 micrograms shifted the dose-response curve of noradrenaline in perfused rat kidney. It can be suggested that ENDO has a potent blocking action on vascular alpha-adrenoceptors without evident discrimination between alpha 1 and alpha 2 subtypes.
mesh_terms: D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001808:Blood Vessels / Q000187:drug effects* / Q000378:metabolism; D004731:Endotoxins / Q000494:pharmacology*; D004926:Escherichia coli; D066298:In Vitro Techniques; D007668:Kidney / Q000187:drug effects; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology; D010477:Perfusion; D051381:Rats; D011919:Rats, Inbred Strains; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects* / Q000502:physiology; D014661:Vasoconstriction / Q000187:drug effects
chemical_list: D004731:Endotoxins; D011942:Receptors, Adrenergic, alpha; D009638:Norepinephrine