Changes of acute-phase proteins in streptozotocin-induced diabetic rats

Quantitative and qualitative changes of serum proteins, apart from glycatio n, have not been sufficiently studied in streptozotocin-induced diabetic ra ts (D), the most common experimental model for diabetes. Thus, we decided t o analyze the serum of diabetic rats by concanavalin A-blotting in comparis on with rats with acute inflammation induced by fermented yeast (Y), in whi ch characteristic alterations of serum proteins have been described. Two mo nths after the streptozotocin treatment, the blood glucose levels were high ly elevated (456+/-24 vs. 124+/-10 mg/dl, p<0.001, n=12), the body weight w as significantly lower than normal (279+/-10 vs. 392+/-6 g, p<0.001, n=12), and serum proteins appeared to be highly glycated (p<0.001) when analyzed by the fructosamine assay, without any significant change in the total seru m protein concentration. Analysis by concanavalin A-blotting, revealed a si gnificant decrease of alpha(1)-inhibitor-3 (alpha(1)-I-3, p<0.05) and an in crease of the beta chain of haptoglobin (beta-Hp, p<0.05) in both D and Y r ats (n=3) compared with control animals. However, acute inflammation caused a marked rise of two prominent acute phase proteins, al-macroglobulin and hemopexin, which did not change appreciably in diabetic rats. Further work will be necessary to evaluate the physiopathological significance of these phenomena which could result from changes of both concentration and glycosy lation of the aforementioned proteins.