Induction of a B1-receptor mediating hypotensive response in young brown Norway rats.
A hypotensive response to intravenously injected des-Arg9-bradykinin was elicited in young male Brown Norway rats (8-12 weeks-old), when the rats were intravenously injected with endotoxin (30 micrograms/kg) 24 h before they were repeatedly injected with bradykinin or des-Arg9-bradykinin. The potency of this inducible dose-dependent hypotensive response to des-Arg9-bradykinin was comparable to that induced by bradykinin on a molar base (3-30 nmol/kg). A hypotensive response to des-Arg9-bradykinin could also be induced when the rats were pretreated with endotoxin 6 h before. However, the potency of the response was less than that induced by 24-h pretreatment. This inducible response to des-Arg9-bradykinin did not occur in old rats (8-10 months old). Intravenous infusion of a B1-receptor antagonist, des-Arg9-[Leu8]-bradykinin, suppressed the hypotensive response of des-Arg9-bradykinin. These results suggest that the B1-receptor, mediating hypotension in rats, was inducible through time-dependent and age-dependent sensitization by endotoxin pretreatment.
Oh-ishi
S
S
Dept. Pharmacol., Sch. Pharmac, Sci., Kitasato Univ., Tokyo, Japan.
Tokumasu
T
T
Ueno
A
A
D000367:Age Factors; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D001920:Bradykinin / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D007022:Hypotension / Q000209:etiology* / Q000503:physiopathology; D008070:Lipopolysaccharides / Q000633:toxicity; D008297:Male; D051381:Rats; D011914:Rats, Inbred BN; D043783:Receptor, Bradykinin B1; D018002:Receptors, Bradykinin / Q000502:physiology*; D013997:Time Factors
D008070:Lipopolysaccharides; D043783:Receptor, Bradykinin B1; D018002:Receptors, Bradykinin; C024626:bradykinin, des-Arg(9)-; D001920:Bradykinin