Concentrations of acute-phase proteins and immunoglobulins in serum and synovial fluid in clinically healthy heifers and steers

Abstract

ABSTRACT: The aim of the study was to determine the concentration pattern of intra-articular acute phase proteins (APPs) and immunoglobulins in healthy crossbred cattle. Synovial fluid (SF) samples were collected from the radiocarpal joint of 25 heifers and 25 steers. Concentrations of APPs were measured by SDS-PAGE. The results were submitted to analysis of variance using the SAS statistical program, and means were compared by the Student-Newman-Keuls test (P<0.05). Thirty-seven proteins with molecular weights ranging from 7 to 37kDa were identified in SF of all animals. Eight were nominally identified with immunoglobulin A (IgA) and G (IgG), ceruloplasmin (Cp), transferrin (Tf), albumin (Ab), α1-antitripsin (AAT), α1-acid glycoprotein (AGP), and haptoglobin (Hp). The α1-antitripsin was only identified in the Sf of the heifers. The SF values of Cp, Hp, AGP and IgA were significantly higher in heifers than in steers. In sera, 34 proteins with molecular weights between 7 and 244kDa were identified in heifers and steers. Similar proteins were nominally identified in the sera, however the α1-antitrypsin was identified only in SF. The serum values Tf, AGP and IgG were significantly higher in heifers compared with steers. In conclusion, the physiological acute-phase proteins concentrations in synovial fluid of healthy ruminants can be useful in the interpretation of samples from animals with joint diseases. The SF electrophoretic profile of healthy ruminants differs depending on gender. Similar proteins were nominally identified in the sera, but only the SF of α1-antitrypsin.