title: Relaxant and contractile responses of porcine pulmonary arteries to thrombin and thrombin receptor activating peptides.
abstract: The vascular effects of thrombin and thrombin receptor activating peptides (TRAP) were studied on isolated rings from porcine pulmonary arteries. In prostaglandin F2 alpha (PGF2 alpha)-precontracted vessels with intact endothelium, both thrombin- and TRAP-induced nitric oxide-mediated relaxation, whereas in endothelium-denuded vessels thrombin and TRAP elicited concentration-dependent contractile responses. The first phasic component of contraction was associated with increased generation of inositol 1,4,5-triphosphate and the tonic component seemed to be due to the activation of protein kinase C. Both peptides (TRAP-6 with 6 and TRAP-14 with 14 amino acid residues) did not differ in their intrinsic activity; like thrombin, both peptides elicited dualistic vascular effects but their potency was more than three orders of magnitude less than that of thrombin.
authors.affiliation: University of Jena, Faculty of Medicine, Center for Vascular Biology and Medicine, Erfurt, Germany.
authors.forename: E
authors.initials: E
authors.lastname: Glusa
authors.forename: M
authors.initials: M
authors.lastname: Paintz
authors.forename: E
authors.initials: E
authors.lastname: Bretschneider
mesh_terms: D000818:Animals; D001158:Arteries / Q000502:physiology*; D015237:Dinoprost / Q000494:pharmacology*; D010455:Peptides / Q000494:pharmacology; D011652:Pulmonary Circulation / Q000502:physiology*; D018179:Receptors, Thrombin / Q000819:agonists; D013552:Swine; D013917:Thrombin / Q000494:pharmacology*; D014661:Vasoconstriction / Q000187:drug effects*; D014664:Vasodilation / Q000187:drug effects*
chemical_list: D010455:Peptides; D018179:Receptors, Thrombin; D015237:Dinoprost; D013917:Thrombin