Activity of vascular hemostasis in milk-fed calves

An investigation of 32 healthy Black Pied and Simmental calves in the milk-feeding stage established a stable content in their blood of acyl hydroperoxides and thiobarbituric acid reactive substances aver- aging in this stage respectively 1.51 D233/ml and 3.53 μmol/L with a tendency toward intensifying the activity of the antioxidant potential of plasma. Against a background of a low level of endotheliocytemia, there was a tendency toward an increase of the index of antiaggregation activity of the vascular wall with all tested inducers (ADP 1.77, collagen 1.63, thrombin 1.53, ristomycin 1.53, epinephrine 1.66) and their combinations (ADP + epinephrine 1.44, ADP + collagen 1.37, epinephrine + collagen 1.49). Endotheliocytes are characterized by intensified production of antithrombin III providing the necessary level of anticoagulants of vascular origin in blood (the index of anticoagulant activity of the vascular wall was 1.32 on average). In this case, secretion of tissue plasminogen activators, revealed upon creating temporary ischemia of the venous wall of calves aged from 11 to 30 days, had a general tendency to intensify (the index of fibrinolytic activity of the vascular wall increased during the stage by 2.1%).