Age-related changes in haptoglobin phenotypes, some non-enzymatic antioxidants and electrophoretic profiles of serum proteins in rats

Abstract

Aim: Determination of age-related changes in levels of some non-enzymatic antioxidants such as serum haptoglobin, haemoglobin and albumin, serum haptoglobin phenotype and serum protein profile was aimed with this study. Methods and results: Fifty Sprague-Dawley male rats were divided equally into five groups as 1 (one-month old), 2 (six-months old), 3 (twelve-months old), 4 (eighteen-months old) and 5 (twenty-four-months old). The serum protein concentrations were measured by autoanalyzer. A decrease was determined in the concentrations of the total protein and albumin related to age. However, no clear decrease in the serum globulin concentrations occurred. Serum haptoglobin concentrations were measured by ELISA and an increase was detected with age. Serum haemoglobin concentrations were increased up to 3 months old, but decreased from 3 to 24 months old of age. The electrophoretic profiles of serum total protein were determined by native-PAGE. No differences were observed in total serum profiles between age groups. To determine serum haptoglobin profiles, western blot was performed and haptoglobin patterns were designated as “aa” (single band) or “ab” (two bands) patterns. The “ab” pattern was more frequently observed in older rats. Also, 15 protein bands ranged between 19 to 244 kDa, were detected by SDS-PAGE. After SDS-PAGE, western blot were performed and three haptoglobin bands (10, 37 and 47 kDa) were detected. Conclusion: The age-related changes in total serum protein, albumin, haemoglobin and haptoglobin concentrations as well as the prevalent haptoglobin phenotypes may be considered as indicators in some age-related diseases.