Selective suppression of type B monoamine oxidase immunoreactivity in the raphe nuclei following MPTP administration in the cat.
Using immunohistochemistry, we investigated in the cat the effects of MPTP, a Parkinsonian syndrome-inducing substance, on brain type B monoamine oxidase (MAO-B) which is responsible for the conversion of MPTP to its neurotoxic product (MPP+). Intraperitoneal administration of MPTP (5 mg kg-1 daily for 5 days) caused a selective suppression of MAO-B in neurones of the raphe nuclei without affecting hypothalamic MAO-B. Since these effects were accompanied by loss of nigral dopaminergic cells but not of raphe cell bodies or 5-HT immunoreactivity, we suggest that MPTP suppresses raphe MAO-B without destroying its presumed host serotoninergic neurones and that raphe MAO-B does not appear to be crucial in the MPTP-induced nigral lesion. In addition, the MPTP-induced paradoxical sleep suppression might be related to this raphe MAO-B loss.
Lin
J S
JS
Département de Médecine Expérimentale, INSERM U52, CNRS URA 1195, Université Claude Bernard, Lyon, France.
Hou
Y
Y
Kitahama
K
K
Jouvet
M
M
D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine / Q000494:pharmacology*; D000818:Animals; D001253:Astrocytes / Q000187:drug effects / Q000201:enzymology; D002415:Cats; D007150:Immunohistochemistry; D008995:Monoamine Oxidase / Q000032:analysis / Q000187:drug effects*; D009474:Neurons / Q000187:drug effects / Q000201:enzymology; D011903:Raphe Nuclei / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology
D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; D008995:Monoamine Oxidase