[Regional and cellular distribution of mitochondrial high-affinity aldehyde dehydrogenase in the rat brain (an...

Immunocytochemical study of regional and cellular distribution of mitochondrial high-affinity aldehyde dehydrogenase (MA AlDH) in the rat CNS was performed by streptavidin-biotin-peroxidase method. Specific immunoreactivity of diverse intensity was found in most structures of brain and spinal cord regions mainly in neuronal and gliocyte cytoplasm and to a smaller extent, in their processes, terminations (neuropile conducting tracts, white matter) and blood vessels: immune reaction intensity of perikarya of different type neurons exceeds those of neuropile 1.8-3.3 times. MA AlDH positive neurons were observed in all the cerebral regions, with the most intensive specific staining in inferior olives and hippocamp pyramidal layer (0.500-0.520 optical density units) and the minimal in nucleus rubrum and substantia nigra (0.260-0.290 units). In both cases MA AlDH immunoreactive neurons made only part (from 40 to 88) of morphologically identified (thianine-positive) neurons. Comparative analysis of histochemical preparations and the cytophotometric results revealed significant diversities in topographic distribution of MA AlDG and general AlDG activity in the cerebrum. The data obtained assist in elucidation the spatial organization of alcohol and aldehyde metabolism in CNS and in comprehension the reasons of different sensitivity of brain structures to alcohol.