The thrombin inhibitor argatroban does not influence the endothelium-dependent relaxant and contractile responses of isolated rabbit carotid arteries
Authors: Schrödter H-M.; Glusa E.
Source: Experimental and Toxicologic Pathology, Volume 54, Numbers 5-6, May 2003 , pp. 499-504(6)
Publisher: Urban & Fischer
Abstract:
Atherosclerotic endothelial dysfunctions are associated with a reduced NO production, which is probably due to impaired NO synthase (eNOS) activity or a deficiency of the substrate L-arginine. In the present studies, the influence of argatroban on isolated rabbit carotid arteries was investigated to determine whether the arginine derivative argatroban can improve the endothelium-dependent relaxation.Rings from rabbit carotid arteries were placed in 10 ml organ baths for isometric tension recording. Endothelial integrity was assessed by the acetylcholine-induced relaxation of PGF2
-precontracted rings; after mechanical removal of the endothelium the relaxation was abolished. Preincubation of the vessels in vitro with L-NAME, an inhibitor of the eNOS, diminished significantly the acetylcholine-induced relaxation by more than 50%. After i.v. application of L-NAME (100 mg/kg) in rabbits, relaxation in response to acetylcholine was significantly reduced compared to the control when the vessels were studied ex vivo in an organ bath. The contractile effects of phenylephrine and 5-HT were slightly enhanced.Argatroban is a selective, potent, synthetic thrombin inhibitor; after i.v. application at doses of 0.5 and 1.0 mg/kg, a significant prolongation of the plasma coagulation time (measured as thrombin time and a PTT) of up to 60 min was found in rabbits.in vitro argatroban did not affect the acetylcholine-induced relaxation or the contractile response to phenylephrine and 5-HT. After i.v. application, the ex vivo experiments in the organ bath showed that after 30 min the relaxant responses of the carotid arteries to acetylcholine and the contractile effects of phenylephrine and 5-HT were not influenced by pretreatment with argatroban. The present studies suggest that argatroban has no vascular effects in vitro and ex vivo in normal rabbits.
Document Type: Research article
DOI: http://dx.doi.org/10.1078/0940-2993-00285
Affiliations: 1: University of Jena, Center for Vascular Biology and Medicine, Erfurt, Germany
Publication date: 2003-05-01
- In this: publication
- By this: publisher
- In this Subject: Ecology , Pathology , Toxicology
- By this author: Schrödter H-M. ; Glusa E.

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