Beta-adrenergic receptor mediated release of tissue plasminogen activator in anaesthetized dogs.
Drugs like epinephrine or isoproterenol can enhance fibrinolytic activity of blood. It is still a matter of debate whether this effect can be totally or only partially blocked by beta-receptor blockers. We have developed a dog model for ex vivo measurement of the fibrinolytic activity using a spectrophotometric assay employing human plasminogen, chromogenic plasmin substrate and human fibrinogen-BrCN digests for the stimulation of t-PA. After i.v. administration of isoproterenol the fibrinolytic activity increased, but this could be seen only in the presence of fibrinogen-BrCN digest in the test system. This suggests that isoproterenol caused higher levels of dog t-PA. Pretreatment with the beta-blocker propranolol completely blocked the increase in t-PA.
Probst
A
A
Medical Research Department, Boehringer Mannheim GmbH, Federal Republic of Germany.
Lill
H
H
Strein
K
K
D000758:Anesthesia; D000818:Animals; D004285:Dogs; D005342:Fibrinolysis / Q000187:drug effects; D007545:Isoproterenol / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D011943:Receptors, Adrenergic, beta / Q000502:physiology*; D010959:Tissue Plasminogen Activator / Q000378:metabolism*
D011943:Receptors, Adrenergic, beta; D011433:Propranolol; D010959:Tissue Plasminogen Activator; D007545:Isoproterenol