Sympathetic-dependence in bradykinin-induced synovial plasma extravasation is dose-related.
While previous studies have implicated a role for sympathetic postganglionic neuron-terminals in bradykinin-induced plasma extravasation, a recent report by Cambridge and Brain [Br. J. Pharmacol., 115 (1995) 641-647] has suggested that it is sympathetic-independent. However, the doses of bradykinin used in these two groups of studies were considerably different. Therefore, in the present study, we characterized the sympathetic-dependence of plasma extravasation at varying doses of bradykinin. By measuring the concentration of Evans blue dye extravasation into the joint perfusate following its intravenous injection, bradykinin-induced plasma extravasation in the knee joint cavity was determined spectrophotometrically. To examine the role of sympathetic postganglionic neuron terminals in mediating bradykinin-induced plasma extravasation, we used surgical ablation of the lumbar sympathetic chain. Intra-articular perfusion of BK dose-dependently increased synovial plasma extravasation. After surgical sympathectomy, the dose-response curve for bradykinin-induced plasma extravasation was significantly shifted to the right. We conclude that at concentrations observed in inflamed tissues (between 10(-8) and 10(-7) M), bradykinin-induced plasma extravasation is largely mediated by sympathetic postganglionic neuron terminals.
Miao
F J
FJ
Department of Medicine, University of California at San Francisco 94143-0452, USA.
Green
P G
PG
Coderre
T J
TJ
Jänig
W
W
Levine
J D
JD
D000818:Animals; D001920:Bradykinin / Q000494:pharmacology*; D004396:Coloring Agents / Q000493:pharmacokinetics; D004305:Dose-Response Relationship, Drug; D005070:Evans Blue / Q000493:pharmacokinetics; D005119:Extravasation of Diagnostic and Therapeutic Materials / Q000378:metabolism; D007719:Knee Joint / Q000276:immunology / Q000378:metabolism / Q000503:physiopathology; D008297:Male; D010949:Plasma / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D017779:Sympathetic Fibers, Postganglionic / Q000187:drug effects* / Q000378:metabolism; D013582:Synovial Fluid / Q000187:drug effects* / Q000378:metabolism; D013585:Synovitis / Q000378:metabolism
D004396:Coloring Agents; D005070:Evans Blue; D001920:Bradykinin