Study of the evolution of acute phase reactants and of thromboxane and prostacyclin during calcium pyrophosphate-induced pleurisy in the rat

Abstract

By using a clearly defined model of acute inflammation in rats, CaPP-induced pleurisy, we compared the evolution of four APR levels (Hp, HpX, α₂M, SAP) at a local and peripheral site. At the same time we studied thromboxane and prostacyclin concentrations in pleural exudate. The levels of APR have shown a progressive increase up to 24 h. For α₂M, Hp, HpX the increase in serum concentration was more rapid than in exudate, whereas the evolution of SAP level was parallel in the intra and extra-vascular compartments. On the other hand the levels of albumin and transferrin which are not APR remained constant in serum and also in exudate from 6 h to 24 h. Thromboxane and prostacyclin levels reached a peak during the first two hours of the inflammatory reaction followed by a rapid decrease. These prostanoids may be considered as early and transient mediators of acute inflammation, whereas the acute phase proteins studied have a more prolonged role in the inflammatory reaction.