RESUMO
Since homocysteine (Hcy) is considered a risk factor to cerebral diseases and adenine nucleotides are important molecules to brain normal function, in the present study we investigated the effect of chronic mild hyperhomocysteinemia on ectonucleotidase activities and expression in rat cerebral cortex. The levels of ATP, ADP, AMP and adenosine (Ado) in cerebrospinal fluid (CSF) of adult rats also were evaluated by high-performance liquid chromatography. For the chronic chemically induced mild hyperhomocysteinemia, Hcy (0.03 µmol/g of body weight) was administered subcutaneously from the 30th to the 60th day of life. Control rats received saline solution in the same volumes. Results showed that Hcy significantly decreased nucleotide hydrolysis in the synaptosomal fraction and increased E-NTPDase1 and ecto-5'-nucleotidase transcripts in rat cerebral cortex. ATP levels were significantly increased, while Ado decreased in CSF of Hcy-treated rats. These findings suggest that the unbalance in ATP and Ado levels may be, at last in part, involved in the cerebral toxicity of mild hyperhomocysteinemia.
Assuntos
Adenina/metabolismo , Encéfalo/patologia , Líquido Extracelular/metabolismo , Hiper-Homocisteinemia/patologia , 5'-Nucleotidase/genética , 5'-Nucleotidase/metabolismo , Difosfato de Adenosina/metabolismo , Adenosina Trifosfatases/genética , Adenosina Trifosfatases/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Encéfalo/metabolismo , Encéfalo/ultraestrutura , Modelos Animais de Doenças , Proteínas Ligadas por GPI/genética , Proteínas Ligadas por GPI/metabolismo , Regulação Enzimológica da Expressão Gênica , Hiper-Homocisteinemia/metabolismo , Purinas/líquido cefalorraquidiano , RNA Mensageiro , Ratos , Ratos Wistar , Frações Subcelulares/metabolismo , Frações Subcelulares/patologia , Sinaptossomos/metabolismoRESUMO
In a continuing comparative study of the sesquiterpenoid and diterpenoid content of the gorgonian Eunicea succinea from different locations, a new cembranolide, 12,13-bisepieupalmerin (6), was isolated (structure by X-ray analysis) from specimens from St. Croix, U.S.V.I. 12,13-Bisepieupalmerin possesses the correct stereochemistry to be a biosynthetic precursor for the related cembranolides eunicin (1a) and jeunicin (2). The latter compounds were found to occur with 6 in E. succinea from St. Croix. Eunicin and its acetate (1b) were obtained from a South Caicos collection. E. succinea from St. Croix, U.S.V.I. and South Caicos contain complex mixtures of hydrocarbons in which (-)-germacrene-A, (+)-beta-elemene, (+)-beta-epibourbonene, (+)-beta-copaene, and (+)-alpha-muurolene were identified.