EFFECT OF EXPERIMENTAL INFLAMMATION ON SYNTHESIS AND DISTRIBUTION OF ANTITHROMBIN-III AND ALPHA-1-ANTITRYPSIN IN RABBITS

Abstract

Local inflammation, induced by s.c. injection of turpentine, evoked characteristic changes in the metabolism of antithrombin III and .alpha.1-antitrypsin. For a period of .apprx. 36 h, the plasma half-lives of both protease inhibitiors were shortened to 70-74% of the respective preinjection values. Similar changes were also observed in the slope of I-labeled albumin, suggesting that increased capillary permeability was primarily responsible for the losses of labeled proteins from the circulation. Incorporation of [3H]- or [14C]-leucine into albumin changed little during inflammation, but markedly increased values were measured for antithrombin III (3-fold), .alpha.1-antitrypsin (4-fold) and for fibrinogen (7-fold) 24 h and 48 h after the injection of turpentine. These changes in synthesis and elimination rates resulted in the following net balances. Fibrinogen concentrations in plasma rose substantially during the early phase of inflammation. .alpha.1-Antitrypsin concentrations increased gradually but to a significantly lesser extent, peak concentration being reached after a reverse trend in fibrinogen concentrations became apparent. Antithrombin III concentrations remained steady throughout at levels which were only marginally above the pretreatment values.