Aldehyde dehydrogenase and aldehyde reductase in isolated bovine brain microvessels

The activities of aldehyde dehydrogenase and aldehyde reductase were measured in microvessel fractions isolated from bovine brain. Aldehyde dehydrogenase specific activity in microvessels was enriched 1.5-fold over that measured in grey matter. The specific activity of aldehyde reductase was significantly lower in parenchymal vessles and microvessels than in grey matter. The presence of aldehyde dehydrogenase and aldehyde reductase in cerebral microvasculature is consistent with previous reports of enrichment of other enzymes involved in synthesis and degradation of monoamines. The enrichment of aldehyde dehydrogenase in cerebral microvasculature provides additional evidence for an enzymatic blood-brain barrier for biogenic aldehydes or ethanol-derived acetaldehyde.