[The contractile response of isolated lingual arteries from rabbits treated with bacterial lipopolysaccharide via the stimulation of B1-receptors for kinins].
The effect of intravenous injection of 10 micrograms of a lipopolysaccharide (endotoxin) extracted from E. coli to rabbits on the responses of isolated lingual arteries to des-Arg9-bradykinin (a specific kinins B1-receptor agonist) was studied. Endotoxin injection led to the appearance of the endothelium-independent contractile effect of des-Arg9-bradykinin in the arteries; endotoxin elicited this response when administered at 1, 5 or 20 hr before the experiment, in a time-interval dependent manner. The contractile response to des-Arg9-bradykinin of the arteries isolated from animals receiving endotoxin 20 hr before the experiment was attenuated by des-Arg9-[Leu8]-bradykinin (a specific inhibitor of kinins B1-receptor) or pretreatment of the animals with an inhibitor of protein synthesis (cycloheximide and actinomycin D). When compared with the effect of des-Arg9-bradykinin, bradykinin (a potent kinin B2-receptor, but weak B1-receptor stimulant) caused slight contraction of the arteries; however, this effect was not endotoxin-dependent and was not modified by des-Arg9-[Leu8]-bradykinin. Effect of in vitro preincubation with endotoxin of the arteries isolated from animals receiving saline 20 hr before the experiment was further studied. The preincubation (for 1 and 5 hr) with endotoxin of the arteries in the presence or absence of plasma had no effect on the sensitivity of the arteries to des-Arg9-bradykinin; the sensitivity was also unaffected in the presence or absence of endotoxin, thus suggesting that there is no interaction between endotoxin and some plasma-related factors with the appearance of the contraction in response to the kinin B1-receptor agonist in the arteries in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)
Department of Pharmacology, Kanagawa Dental College, Japan.
M
M
Sugihara
K
K
Todoki
E
E
Okabe
D000818:Animals; D001158:Arteries / Q000187:drug effects; D001920:Bradykinin / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors / Q000494:pharmacology; D003513:Cycloheximide / Q000494:pharmacology; D003609:Dactinomycin / Q000494:pharmacology; D004731:Endotoxins / Q000494:pharmacology*; D004926:Escherichia coli; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D011817:Rabbits; D014059:Tongue / Q000098:blood supply*
D004731:Endotoxins; C024626:bradykinin, des-Arg(9)-; D003609:Dactinomycin; C051090:bradykinin, Leu(8)-des-Arg(9)-; D003513:Cycloheximide; D001920:Bradykinin