Microvascular effects of bradykinin in the isolated perfused guinea-pig hindbrain: method and characterization of a possible third type of bradykinin receptor.
The method used by McGregor for the isolated mesenteric vascular bed was adapted to study the mechanisms of regulation of cerebral blood flow in the isolated perfused guinea-pig brain. This method allows the recording of the perfusion pressure in the hindbrain perfused at constant physiological flow, and has been successfully applied to the study of the effect of bradykinin. Bradykinin elicited a vasoconstriction that was independent of the presence of the endothelium. The pD2 ranged between 7.50 and 7.60, respectively, with and without the endothelium. Des-Arg9-BK was unable to elicit a vasoconstriction. [Tyr(Me)8]BK had a partial agonist activity. Both [Leu9]des-Arg10-KD and [DArg0,Hyp3,DPhe7]BK had similar antagonist activities. From these pharmacological characteristics, the receptor involved in this response seems to be different from a B1 or a B2 receptor.
Cohen-Laroque
E S
ES
Department of Animal Biology, University of Geneva, Switzerland.
Bény
J L
JL
Huggel
H
H
D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D001920:Bradykinin / Q000031:analogs & derivatives / Q000494:pharmacology*; D005260:Female; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008833:Microcirculation; D018002:Receptors, Bradykinin; D017981:Receptors, Neurotransmitter / Q000187:drug effects / Q000378:metabolism*; D012249:Rhombencephalon / Q000098:blood supply* / Q000187:drug effects; D014661:Vasoconstriction / Q000187:drug effects*
D000318:Adrenergic beta-Agonists; D000319:Adrenergic beta-Antagonists; D018002:Receptors, Bradykinin; D017981:Receptors, Neurotransmitter; D001920:Bradykinin