半乳糖血症体外培养乳鼠脑区的Mg2 + -ATP酶活性。L-半胱氨酸和谷胱甘肽的作用。

Mg2+-ATPase activity in suckling rat brain regions in galactosaemia in vitro. L-Cysteine and glutathione effects.

作者信息

Marinou Kyriakoula, Tsakiris Stylianos, Tsopanakis Christi, Schulpis Kleopatra H, Behrakis Panagiotis

机构信息

Department of Experimental Physiology, Medical School, University of Athens, P.O. Box 65257, GR-15401 Athens, Greece.

出版信息

Toxicol In Vitro. 2005 Mar;19(2):167-72. doi: 10.1016/j.tiv.2004.06.010.

DOI:10.1016/j.tiv.2004.06.010

PMID:15649629

Abstract

UNLABELLED

Mg2+-ATPase activity is implicated with Mg2+ homeostasis, maintaining high brain intracellular Mg2+ content. We determined the in vitro effects of galactose-1-phosphate (Gal-1-P), galactitol (Galtol) and galactose (Gal) {mix A=Gal-1-P(2 mM)+Galtol(2 mM)+Gal(4 mM) concentrations commonly found in patients with classical galactosaemia} or Galtol and Gal {mix B=Galtol(2 mM)+Gal(1 mM) concentrations usually measured in patients with galactokinase deficiency galactosaemia} on Mg2+-ATPase activity in suckling rat brain frontal cortex, hippocampus or hypothalamus homogenates. Gal-1-P significantly (p<0.001) enhanced enzyme activity in all the brain areas measured, whereas Galtol and Gal failed to cause any effect in the same regions. Mix A remarkably (p<0.001) stimulated Mg2+-ATPase in the studied areas. On the contrary, mix B had no effect. The supplementation of antioxidant l-cysteine (Cys) or reduced Glutathione (GSH) in mix A failed to reverse to normal the activated enzyme in frontal cortex and hypothalamus, while they significantly reduced Mg2+-ATPase activation in hippocampus.

CONCLUSIONS

(a) Gal-1-P enormously activated Mg2+-ATPase in all the studied brain regions, (b) Mix A, also, excessively activated the enzyme in the same areas, (c) the production of free radicals may be implicated with the enzyme activation and (d) Cys or GSH significantly decreased the activated hippocampal Mg2+-ATPase.

摘要

未标记

镁离子 - ATP酶活性与镁离子稳态相关，维持大脑细胞内高镁含量。我们测定了半乳糖 - 1 - 磷酸（Gal - 1 - P）、半乳糖醇（Galtol）和半乳糖（Gal）{混合物A = Gal - 1 - P（2 mM）+ Galtol（2 mM）+ Gal（4 mM），经典半乳糖血症患者常见的浓度}或Galtol和Gal{混合物B = Galtol（2 mM）+ Gal（1 mM），半乳糖激酶缺乏性半乳糖血症患者通常测得的浓度}对乳鼠脑额叶皮质、海马或下丘脑匀浆中镁离子 - ATP酶活性的体外影响。Gal - 1 - P显著（p < 0.001）增强了所有测量脑区的酶活性，而Galtol和Gal在相同区域未产生任何影响。混合物A显著（p < 0.001）刺激了所研究区域的镁离子 - ATP酶。相反，混合物B没有作用。在混合物A中添加抗氧化剂L - 半胱氨酸（Cys）或还原型谷胱甘肽（GSH）未能使额叶皮质和下丘脑的激活酶恢复正常，而它们显著降低了海马中镁离子 - ATP酶的激活。