Histochemical localisation of monoamine oxidase A and B in rat brain.
The histochemical distribution of monoamine oxidase A and B in rat brain was investigated using a coupled peroxidatic technique with benzylamine and tyramine as substrates and clorgyline and (-)-deprenyl as selective inhibitors. Benzylamine oxidase was absent in all areas. Both forms of monoamine oxidase were present, at low levels, in all areas; in addition several regions showed high activity of one or other form or both. Substantial activity of monoamine oxidase B was identified in the pineal gland, the lining of the ventricles, several hypothalamic regions, and the raphe nuclei. The locus coeruleus and interpeduncular nucleus possessed considerable type A activity. The substantia nigra and striatum showed no staining above the low general level, although the ventral tegmental area showed higher levels of both A and B. In general, noradrenaline-containing neuronal cell body areas showed monoamine oxidase A, and 5-hydroxytryptamine-rich areas monoamine oxidase B. There was no consistent enrichment of either in corresponding dopamine-rich regions. Monoamine oxidase thus appears to have a different role in these three types of neuron. The low level of monoamine oxidase B in the nigrostriatal tract may help to explain the resistance of the rat to MPTP toxicity.
Willoughby
J
J
Bernhard Baron Memorial Research Laboratories, Queen Charlotte's Hospital, London, U.K.
Glover
V
V
Sandler
M
M
D000818:Animals; D001921:Brain / Q000201:enzymology*; D002552:Cerebral Ventricles / Q000201:enzymology; D006651:Histocytochemistry; D008125:Locus Coeruleus / Q000201:enzymology; D008297:Male; D008995:Monoamine Oxidase / Q000032:analysis*; D010870:Pineal Gland / Q000201:enzymology; D051381:Rats; D011919:Rats, Inbred Strains
D008995:Monoamine Oxidase