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Thromb Haemost 1982; 47(01): 046-049
DOI: 10.1055/s-0038-1657122
Original Article
Schattauer GmbH Stuttgart

Prolongation of Rat Tail Bleeding Time Caused by Oral Doses of a Thromboxane Synthetase Inhibitor Which Have Little Effect on Platelet Aggregation

K D Butler
The Ciba-Geigy Pharmaceuticals Division, Research Centre, Horsham, U.K.
,
E D Maguire
The Ciba-Geigy Pharmaceuticals Division, Research Centre, Horsham, U.K.
,
J R Smith
The Ciba-Geigy Pharmaceuticals Division, Research Centre, Horsham, U.K.
,
A A Turnbull
The Ciba-Geigy Pharmaceuticals Division, Research Centre, Horsham, U.K.
,
R B Wallis
The Ciba-Geigy Pharmaceuticals Division, Research Centre, Horsham, U.K.
,
A M White
The Ciba-Geigy Pharmaceuticals Division, Research Centre, Horsham, U.K.
› Author Affiliations
Further Information

Publication History

Received 02 July 1981

Accepted 23 December 1981

Publication Date:
13 July 2018 (online)

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Summary

N (7-carboxyheptyl) imidazole is an inhibitor of platelet thromboxane synthetase that has no effect on the cyclooxygenase activity. An oral dose of the substance to rats (10 mg/kg) prolonged tail bleeding time from 170 ± 13 sec to 284 ± 22 sec. This oral dose also inhibited platelet thromboxane B2 production induced by collagen ex vivo but had little effect on the aggregation dose response curve. There was no effect on thrombin-induced aggregation.

Neither the thrombocytopenia induced by the Arthus reaction nor thrombus formation on an implanted cotton thread were inhibited by oral doses of carboxyheptylimidazole up to 30 mg/kg. Similarly neither the prothrombin nor activated partial thromboplastin time were affected.

It is postulated that this thromboxane synthetase inhibitor prolongs bleeding time not by inhibiting platelet aggregation or blood coagulation but rather by preventing the vasoconstriction which would normally be caused by thromboxane A2.

Key words

Keywords Bleeding time - Thromboxane synthetase inhibitor - Thromboxane B2 - Platelet aggregation
 

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