Localization of adenosine deaminase and adenosine deaminase complexing protein in rabbit brain.

Adenosine deaminase and adenosine deaminase complexing protein have beenlocalized in rabbit brain. Brains fixed in paraformaldehyde or in Clarke’s solution were blocked coronaily. Blocks from brains fixed in paraformaldehyde were either frozen in liquid nitrogen or embedded in paraffin. Tissue fixed in Clarke’s solution was embedded in paraffin. Sections from each block were stained by the peroxidase-antiperoxidase method for adenosine deaminase or complexing protein using affinity-purified goat antibodies. Adenosine deaminase and complexing protein did not co-localize. Adenosine deaminase was detected in oligodendroglia and in endotheial cells lining blood vessels, whereas complexing protein was concentrated in neurons. The subcellular location and appearance of the peroxidase reaction product associated with individual cells was also quite distinctive. The cell bodies ofadenosine deaminase-positive oligodendroglia were filled with intense deposits ofperoxidase reaction product. In contrast to oligodendroglia, the reaction product as