concanavalin-a and bindarit

In the rat, injection of Freund's complete adjuvant was accompanied by a significant increase in concanavalin A (Con A)-reactivity of selected plasma proteins along with an increase in concentrations of selected proteins known as acute phase proteins. We have evaluated the effect of bindarit, (2-[(1-benzyl-indazol-3-yl)methoxy]-2-methyl propionic acid), on the expression of alpha 2-macroglobulin, a known acute-phase protein in the rat. This compound has previously been shown to inhibit heat-induced denaturation of rat serum albumin and to strongly reduce the secondary phase response of adjuvant induced arthritis. Adult rats were induced with chronic inflammation by injection with Freund's complete adjuvant. Bindarit was administered to the chronic inflamed rats as a 0.5% medicated diet. Indomethacin, given by gavage daily at a dose of 1 mg/kg body weight, was used as a reference drug. Qualitative and quantitative changes of Con A-reactive proteins and alpha 2-macroglobulin were examined by lectin- and immuno-blots, and by radioimmunoassay. It was noted that the concentration of alpha 2-macroglobulin increased in rats with adjuvant induced arthritis. The addition of bindarit and indomethacin were able to reduce the concentration of alpha 2-macroglobulin as well as the Con A-reactivity of various proteins to normal level 37 days following treatment. We have also examined the effects of chronic inflammation on the levels of rat clusterin, a testicular and serum glycoprotein related to programmed cell death, tissue regression, and complement cascade reaction; and testibumin, a testicular FSH and testosterone-responsive protein with unknown function. It was noted that chronic inflammation did not induce significant changes in both the clusterin and testibumin concentrations in these experimental groups. The involvement of protein glycosylation and denaturation in the production of new antigenic determinants, their role in the development of chronic inflammatory disease and the potential use of bindarit to investigate the relationship between abnormal glycosylation and autoimmune disease were discussed.

Topics: Acute-Phase Proteins; alpha-Macroglobulins; Animals; Arthritis, Experimental; Clusterin; Concanavalin A; Electrophoresis, Polyacrylamide Gel; Glycoproteins; Indazoles; Indomethacin; Male; Molecular Chaperones; Propionates; Proteins; Radioimmunoassay; Rats; Saposins; Serum Albumin

Induction of arthritis in rats with Freund's complete adjuvant was accompanied by a distinctive alteration of concanavalin A (Con-A) reactivity in their serum proteins in which the concentrations of selected Con-A reactive proteins were significantly higher when compared to healthy rats. To assess if the observed increase in Con-A reactivity of specific serum proteins reflects an increase in carbohydrate moieties in these proteins in addition to an increase in their protein concentrations, a heme binding serum glycoprotein, hemopexin, also an acute phase reactant, was selected as a marker protein. Hemopexin was purified to apparent homogeneity from pools of serum samples derived from rats with yeast induced inflammation, a monospecific polyclonal antibody was prepared and was used for immunoblot analysis. It was noted that the concentration of hemopexin increased in rats with adjuvant induced arthritis; however, its concentration fell to normal levels after administration with a newly synthesized drug, bindarit, (2-[(1-benzyl-indazol-3-yl)methoxy]-2-methyl propionic acid, C19H20N2O3. Hemopexin was micropurified individually from healthy rats, adjuvant induced arthritic rats, and adjuvant arthritic rats treated with bindarit, cleaved with a Glu-C endopeptidase, Staphylococcus aureus protease V8, and the resultant peptide fragments resolved by SDS-PAGE and examined by silver staining, Coomassie blue staining, and lectin blots using Con-A. It was subsequently noted that hemopexin isolated from adjuvant induced arthritic rats showed a significant increase in Con-A reactivity in selected peptide fragments and that such an increase in glycosylation could be reversed to a pattern similar to healthy rats following treatment with bindarit.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Acute-Phase Reaction; Amino Acid Sequence; Animals; Arthritis, Experimental; Blood Proteins; Chromatography, High Pressure Liquid; Concanavalin A; Electrophoresis, Polyacrylamide Gel; Endopeptidases; Freund's Adjuvant; Glycosylation; Hemopexin; Immunoblotting; Indazoles; Molecular Sequence Data; Propionates; Rats; Rats, Sprague-Dawley; Staining and Labeling