title: Preventive Effect of 3,5-dihydroxy-4-methoxybenzyl Alcohol (DHMBA) and Zinc, Components of the Pacific Oyster Crassostrea gigas, on Glutamatergic Neuron Activity in the Hippocampus.
abstract: The effects of 3,5-dihydroxy-4-methoxybenzyl alcohol (DHMBA), and zinc--both components of the Pacific oyster Crassostrea gigas--were examined by glutamatergic neuron activity in rats in an in vivo microdialysis experiment and an in vitro brain slice experiment. The basal concentration of extracellular glutamate in the hippocampus was decreased under hippocampal perfusion with DHMBA (1 mmol l(-1)) or ZnCl2 (μmol l(-1)), indicating that DHMBA and Zn(2+) suppress glutamatergic neuron activity under basal (static) conditions. To assess the preventive effect of DHMBA and Zn(2+) on glutamate release from neuron terminals, brain slices were pretreated with DHMBA (1 mmol l(-1)) or ZnCl2 (100 nmol l(-1)) for 1 h, then stimulated with high K(+). A high, K(+)-induced increase in extracellular Zn(2+) level, an index of glutamate release, was suppressed with pretreatment with DHMBA or zinc. A high, K(+)-induced increase in intracellular Ca(2+) level was also suppressed with pretreatment with DHMBA or Zn(2+). These results suggest that DHMBA and Zn(2+), previously taken up in the hippocampal cells, suppress high, K(+)-induced glutamate release in the hippocampus, probably via presynaptic suppression of intracellular Ca(2+) signaling. It is likely that Zn(2+) and DHMBA play a preventive role in suppressing excess glutamatergic neuron activity in rats and mice.
authors.affiliation: Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka 422-8526, Japan;
authors.forename: Haruna
authors.initials: H
authors.lastname: Tamano
authors.affiliation: Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka 422-8526, Japan;
authors.forename: Yukina
authors.initials: Y
authors.lastname: Shakushi
authors.affiliation: Watanabe Oyster Laboratory Co. Ltd., 490-3, Shimo-ongata-cho, Hachioji 190-0154, Japan; and.
authors.forename: Mitsugu
authors.initials: M
authors.lastname: Watanabe
authors.affiliation: Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka 422-8526, Japan;
authors.forename: Kazumi
authors.initials: K
authors.lastname: Ohashi
authors.affiliation: Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka 422-8526, Japan;
authors.forename: Chihiro
authors.initials: C
authors.lastname: Uematsu
authors.affiliation: Department of Organic Chemistry, School of Pharmaceutical Sciences, Hiroshima International University, Kure 737-0112, Japan.
authors.forename: Tadamune
authors.initials: T
authors.lastname: Otsubo
authors.affiliation: Department of Organic Chemistry, School of Pharmaceutical Sciences, Hiroshima International University, Kure 737-0112, Japan.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Ikeda
authors.affiliation: Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka 422-8526, Japan; takedaa@u-shizuoka-ken.ac.jp.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Takeda
mesh_terms: D000818:Animals; D000840:Anisoles / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism; D002712:Chlorides / Q000494:pharmacology*; D049896:Crassostrea / Q000737:chemistry*; D018698:Glutamic Acid / Q000378:metabolism*; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D051379:Mice; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D011188:Potassium / Q000378:metabolism; D051381:Rats; D015398:Signal Transduction; D017967:Zinc Compounds / Q000494:pharmacology*
chemical_list: D000840:Anisoles; D000975:Antioxidants; D002712:Chlorides; D017967:Zinc Compounds; D018698:Glutamic Acid; C066943:anisyl alcohol; C016837:zinc chloride; D011188:Potassium; D002118:Calcium