Localization of L-DOPA uptake and decarboxylating neuronal structures in the cat brain using dopamine immunohistochemistry.
The present study examined dopamine-immunoreactive neuronal structures using immunohistochemistry in conjunction with an anti-dopamine antiserum, following injection of l-3,4-dihydroxyphenylalanine (L-DOPA) with or without an inhibitor of monoamine oxidase (Pargyline) in the cat brain. L-DOPA injection made it possible to detect dopamine immunoreactivity in presumptive serotonergic and noradrenergic cell bodies and axons. Weak to moderate dopamine immunoreactivity was observed in non-aminergic cells (possibly so-called "D" cells containing aromatic L-amino acid decarboxylase (AADC)) in several hypothalamic, midbrain, pontine and medullary nuclei. Intense dopamine immunoreactivity became visible in a large number of cells and axons (possibly containing AADC) with wide distribution in the brain following administration of L-DOPA with Pargyline. AADC is most likely active in cells and axons that take up L-DOPA, where it decarboxylates the L-DOPA to dopamine. However, newly synthesized dopamine in such cells is rapidly oxidized by monoamine oxidase.
Kitahama
Kunio
K
Laboratorie de Physiologie Intégrative, Cellulaire et Moléculaire, CNRS UMR5123/Université Lyon1, Bat Raphaël Dubois, Campus La Doua, 43 Bd du 11 Novembre 1918, 69622 Villeurbanne Cedex, France. kunio.kitahama@univ-lyon1.fr
Geffard
Michel
M
Araneda
Silvia
S
Arai
Ryohachi
R
Ogawa
Keiko
K
Nagatsu
Ikuko
I
Pequignot
Jean-Marc
JM
D000818:Animals; D001142:Aromatic-L-Amino-Acid Decarboxylases / Q000378:metabolism*; D001369:Axons / Q000378:metabolism; D001921:Brain / Q000033:anatomy & histology* / Q000378:metabolism*; D002415:Cats; D004298:Dopamine / Q000096:biosynthesis*; D007150:Immunohistochemistry / Q000379:methods; D007980:Levodopa / Q000378:metabolism* / Q000494:pharmacology; D008996:Monoamine Oxidase Inhibitors / Q000494:pharmacology; D009448:Neurochemistry / Q000379:methods; D009474:Neurons / Q000378:metabolism*; D009638:Norepinephrine / Q000378:metabolism; D010293:Pargyline; D012701:Serotonin / Q000378:metabolism
D008996:Monoamine Oxidase Inhibitors; D012701:Serotonin; D007980:Levodopa; D010293:Pargyline; D001142:Aromatic-L-Amino-Acid Decarboxylases; D004298:Dopamine; D009638:Norepinephrine