Effects of S-hexyl-L-cysteine derivatives on prothrombin activation and clotting time determined in the presence of heparin.

PURPOSE The aim of the study is the examination of effects of dipeptides containing S-hexyl-L-cysteine and glycine, on the prothrombin activation and the thrombin clotting time determined in the presence of heparin. MATERIAL AND METHODS The activation of prothrombin was determined with the use of the thromboplastin test, the recalcification and partial thromboplastin with kaolin tests. The thrombin clotting time determined in the presence of heparin was evaluated with the use of the heparin-thrombin test. RESULTS The investigated derivatives slightly inhibited the prothrombin activation. The unsubstituted derivatives and dipeptides with a free amino or carboxyl group significantly enhanced the clotting time determined in the presence of heparin at concentration 20 mM. S-Hexyl-L-cysteinylglycine (H-(S-hexyl)-L-Cys-Gly-OH) was the most active compound. CONCLUSIONS The obtained results indicate that some dipeptide derivatives of S-hexyl-L-cysteine apart from the earlier observed possibility to prolong the thrombin clotting time, can also prolong the clotting time determined in the presence of heparin.