Variation of the α₂-Macroglobulin Homologue with Age in some Mammals

Abstract

The α₂-macroglobulin concentration in rat serum and dog serum was determined by an enzymatic method as well as by an immunochemical method. The results obtained showed a close correlation, indicating that the enzymatic method can be used for determination of the α₂-macroglobulin homologue in sera from various mammalian species. The α₁-macroglobulin in the rat is very probably an α₂-macroglobulin despite its electrophoretic mobility.

The concentration of α₂-macroglobulin in serum from the young rat and ox was significantly lower than in serum from the adult animal. In the dog the serum concentration of α₂-macroglobulin was slightly higher in young animals than in adult ones. None of the species studied showed the remarkable variation with age seen in man.

Key Words:

• Alpha₂-globulins
• macroglobulins
• trypsin inhibitors