Intracoronary beta2 receptor activation induces dynamic local t-PA release in the pig.
To investigate beta2 -adrenergic agonist-mediated effects on coronary fluxes of local fibrinolytic factors, healthy anaesthetised and instrumented pigs (n=10) were studied during infusion of isoprenaline (IPR) into the left main coronary artery. Coronary net fluxes of total t-PA antigen, active t-PA and total PAI-1 antigen were determined at baseline and at 3, 5, 7 and 10 minutes of IPR infusion. During IPR, net release of total t-PA increased in a biphasic pattern with transiently high levels at 3 (+440 %) and 7 minutes (+620%) and returned towards baseline at 10 minutes. Net coronary release of active t-PA increased with maximum levels at 3 minutes (+50%). Baseline coronary net flux of total PAI -1 showed a decrease which was most pronounced at 10 minutes. To conclude, a fast beta2 agonist-mediated local release of t-PA into the coronary vasculature was demonstrated. For total t-PA, this response was characterised by a biphasic release profile.
Dept. of Cardiothoracic Anaesthesiology and Intensive Care, Heart Centre, Umeå University, Umeå, Sweden. barbro.osterlund@vll.se
Barbro
B
Osterlund
Christina
C
Jern
Helene
H
Seeman-Lodding
Göran
G
Johansson
Sören
S
Häggmark
Michael
M
Broomé
Björn
B
Biber
D000322:Adrenergic Agonists / Q000494:pharmacology*; D058666:Adrenergic beta-2 Receptor Agonists; D000818:Animals; D002404:Catheterization; D003331:Coronary Vessels / Q000378:metabolism* / Q000502:physiology; D005260:Female; D005342:Fibrinolysis; D006439:Hemodynamics / Q000187:drug effects; D007545:Isoproterenol / Q000494:pharmacology; D007700:Kinetics; D017395:Plasminogen Activator Inhibitor 1 / Q000097:blood; D018343:Receptors, Adrenergic, beta-2 / Q000097:blood*; D013552:Swine; D010959:Tissue Plasminogen Activator / Q000097:blood*
D000322:Adrenergic Agonists; D058666:Adrenergic beta-2 Receptor Agonists; D017395:Plasminogen Activator Inhibitor 1; D018343:Receptors, Adrenergic, beta-2; D010959:Tissue Plasminogen Activator; D007545:Isoproterenol