Histochemical characterization of monoamine oxidase in ependyma of rat hypothalamus.
Monoamine oxidase (MAO) activity has been demonstrated histochemically in rat hypothalamic ependyma using the sulphate-tetrazolium and coupled peroxidatic techniques with tryptamine, tyramine, 5-hydroxytryptamine and benzylamine as substrates. Both methods were applied to cryostat sections with and without exposure to selective amine oxidase inhibitors, including the selective A-MAO inhibitor clorgyline, and the B-MAO inhibitor deprenyl. Our results show that both cuboidal-columnar and tanycyte ependyma contain one or more forms of MAO not generally present in the hypothalamus. It is suggested that ependymal MAO may form an amine-barrier system modulating the movement and effect within the hypothalamus of specific cerebrospinal fluid or blood monoamines.
D000818:Animals; D001596:Benzylamines / Q000378:metabolism; D004805:Ependyma / Q000201:enzymology*; D005260:Female; D006651:Histocytochemistry / Q000379:methods; D007031:Hypothalamus / Q000201:enzymology*; D008297:Male; D008995:Monoamine Oxidase / Q000032:analysis* / Q000378:metabolism; D008996:Monoamine Oxidase Inhibitors / Q000494:pharmacology; D051381:Rats; D012701:Serotonin / Q000378:metabolism; D014363:Tryptamines / Q000378:metabolism; D014439:Tyramine / Q000378:metabolism
D001596:Benzylamines; D008996:Monoamine Oxidase Inhibitors; D014363:Tryptamines; D012701:Serotonin; D008995:Monoamine Oxidase; D014439:Tyramine