[Antithrombin III activity in long-developing hypercoagulation in animals].

Old rats aged 12-18 months and rats kept on an atherogenic diet for 3.5 months demonstrate high blood antithrombin III content at the initial period of the development of anticoagulation function suppression and of hypercoagulation. During long-developing hypercoagulation, the high content of antithrombin III might be regarded as compensatory reaction interfering with formation in the blood of thrombin microamounts. With hypercoagulation becoming more pronounced and with a further increase of blood thrombin concentration the content of antithrombin III progressively descends, which is accompanied by steady development of anticoagulation function suppression.