title: Hypothesis with abnormal amino acid metabolism in depression and stress vulnerability in Wistar Kyoto rats.
abstract: While abnormalities in monoamine metabolism have been investigated heavily per potential roles in the mechanisms of depression, the contribution of amino acid metabolism in the brain remains not well understood. In additional, roles of the hypothalamus-pituitary-adrenal axis in stress-regulation mechanisms have been of much focus, while the contribution of central amino acid metabolism to these mechanisms has not been well appreciated. Therefore, whether depression-like states affect amino acid metabolism and their potential roles on stress-regulatory mechanisms were investigated by comparing Wistar Kyoto rats, which display depression-like behaviors and stress vulnerability, to control Wistar rats. Brain amino acid metabolism in Wistar Kyoto rats was greatly different from normal Wistar rats, with special reference to lower cystathionine and serine levels. In addition, Wistar Kyoto rats demonstrated abnormality in dopamine metabolism compared with Wistar rats. In the case of stress response, amino acid levels having a sedative and/or hypnotic effect were constant in the brain of Wistar Kyoto rats, though these amino acid levels were reduced in Wistar rats under a stressful condition. These results suggest that the abnormal amino acid metabolism may induce depression-like behaviors and stress vulnerability in Wistar Kyoto rats. Therefore, we hypothesized that abnormalities in amino acid and monoamine metabolism may induce depression, and amino acid metabolism in the brain may be related to stress vulnerability.
authors.affiliation: Laboratory of Regulation in Metabolism and Behavior, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka 812-8581, Japan.
authors.forename: Mao
authors.initials: M
authors.lastname: Nagasawa
authors.forename: Yumi
authors.initials: Y
authors.lastname: Ogino
authors.forename: Koji
authors.initials: K
authors.lastname: Kurata
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Otsuka
authors.forename: Jyunki
authors.initials: J
authors.lastname: Yoshida
authors.forename: Shozo
authors.initials: S
authors.lastname: Tomonaga
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Furuse
mesh_terms: D000596:Amino Acids / Q000008:administration & dosage* / Q000378:metabolism; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D015306:Biogenic Monoamines / Q000378:metabolism; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D003540:Cystathionine / Q000378:metabolism; D003863:Depression / Q000188:drug therapy / Q000378:metabolism* / Q000503:physiopathology; D006993:Hypnotics and Sedatives / Q000008:administration & dosage* / Q000378:metabolism; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects / Q000378:metabolism* / Q000503:physiopathology; D008297:Male; D009928:Organ Specificity; D010913:Pituitary-Adrenal System / Q000187:drug effects / Q000378:metabolism* / Q000503:physiopathology; D051381:Rats; D011921:Rats, Inbred WKY; D017208:Rats, Wistar; D012694:Serine / Q000378:metabolism; D013045:Species Specificity; D013312:Stress, Physiological / Q000187:drug effects; D013550:Swimming
chemical_list: D000596:Amino Acids; D015306:Biogenic Monoamines; D006993:Hypnotics and Sedatives; D003540:Cystathionine; D012694:Serine