Zinc benzoate, a contaminating environmental compound derived from polystyrene resin inhibits A-type monoamine oxidase.
The contaminants in deionized and distilled water (DDI water) boiled with polystyrene resin inhibited A-type monoamine oxidase (MAO, MAO-A preferentially deaminates serotonin and norepinephrine and regulates these amines concentration) activity in monkey brain mitochondria. To identify these contaminants, we attempted measurements by HPLC, FT-IR and NMR. The compound inhibiting MAO-A activity was zinc benzoate. Although it potently inhibited MAO-A activity, zinc benzoate did not effect MAO-B in monkey brain mitochondria. It also reversibly and competitively inhibited MAO-A activity in a dose-dependent manner. Zinc benzoate, however, did not inhibit either MAO-A or -B activities in rat brain mitochondria. These results indicate that zinc benzoate, which inhibits MAO-A activity, is easily incorporated in DDI water by boiling polystyrene and also may be a contaminating environmental chemical compound that alters the levels of serotonin and norepinephrine in the central nervous system.
Department of Pharmacology, Oita Medical University, 1-1 Idaigaoka, Hasama-machi, Oita 879-5593, Japan. takayam@oita-med.ac.jp
Toru
T
Egashira
Kumiko
K
Sakai
Fusako
F
Takayama
Mami
M
Sakurai
Satoshi
S
Yoshida
D000818:Animals; D001565:Benzoates / Q000737:chemistry / Q000494:pharmacology*; D001921:Brain / Q000187:drug effects / Q000201:enzymology; D002851:Chromatography, High Pressure Liquid; D000882:Haplorhini; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008928:Mitochondria / Q000187:drug effects / Q000201:enzymology; D008995:Monoamine Oxidase / Q000378:metabolism*; D008996:Monoamine Oxidase Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D011137:Polystyrenes / Q000737:chemistry*; D051381:Rats; D017208:Rats, Wistar; D017550:Spectroscopy, Fourier Transform Infrared; D015032:Zinc / Q000737:chemistry / Q000494:pharmacology*
D001565:Benzoates; D008996:Monoamine Oxidase Inhibitors; D011137:Polystyrenes; D008995:Monoamine Oxidase; D015032:Zinc