Differential changes in alpha(2)-macroglobulin and hemopexin in brain and liver in response to acute inflammation

Changes in serum and cerebrospinal fluid (CSF) proteins following generaliz ed acute inflammation induced by fermented yeast in the rat was examined by concanavalin A-blotting, immunoblotting, and radioimmunoassay. Using alpha (2)-macroglobulin (alpha(2)-M) and hemopexin (HPX) as marker proteins, the concentration alpha(2)-M was found to increase in serum and CSF by 150- and 5-fold, respectively, whereas the concentration of HPX increased by about 4-fold in both fluids following yeast-induced inflammation. The lesser incr ease in alpha(2)-M in the CSF versus the systemic circulation is not likely to be the result of changes in the permeability of the blood-brain barrier , since no change in the total protein content of CSF was detected in infla med rats when compared to control animals. These results, however, illustra te the regulation of the same protein, such as alpha(2)-M, in two separate organs within the same animal can be drastically different. These results a lso suggest a possible protective role of alpha(2)-M in the brain during ac ute inflammation. Moreover, these observations are consistent with the prev ious observation that there is a differential response in the level of alph a(2)-M between the testis and the systemic circulation during inflammation.