Anticoagulant effect of various crystallohydrates of tungstophosphoric acid and their Na salt and proposed acting mechanism

Abstract

The influence of various crystalohydrates of tungstophosphoric acid (WPA): 29-WPA, 6-WPA, 0-WPA and ''D''-WPA, as well as of various crystalohydrates of neutral Na salt (Na(3)WPA): 16-Na(3)WPA, 6-Na(3)WPA and 0-Na(3)WPA, were tested for their tit vitro effect on plasma coagulation by ''screening'' tests - by measuring aPTT, TT and PT. It was found that different crystalohydrates of WPA prolong aPTT according to the number of water molecules, slightly reduce TT, no matter of water molecules, and have no significant effect on PT: Na(3)WPA acts in the same way as WPA, but in a ten times higher concentration. aPTT prolongation is caused mainly by inhibition of Factor Ut. When WPA is added to plasma together with heparin, aPTT is more prolonged and TT is shortened, while Na(3)WPA with heparin prolongs both aPTT and TT. The proposed mechanism of WPA and Na(3)WPA activity is the charge interaction with ATIII and through hydrogen bonding with Factor IX.