Abstract
Galactosaemia is an inborn error of galactose (Gal) metabolism characterized by irreversible brain damage. The aim of this study was to evaluate whether the antioxidants l-cysteine (Cys) and the reduced glutathione (GSH) could reverse the alterations of brain total antioxidant status (TAS) and the modulated activities of the enzymes Na +,K +-ATPase and Mg 2+-ATPase in in vitro galactosaemia. Mixture A (mix. A: galactose-1-phosphate (Gal-1-P, 2 mM) plus galactitol (Galtol, 2 mM) plus Gal (4 mM) = classical galactosaemia) or Mixture B (mix. B: Galtol (2 mM) plus Gal (1 mM) = galactokinase deficiency galactosaemia) were preincubated in the presence or absence of Cys (0.83 mM) or GSH (0.83 mM) with whole brain homogenates of suckling rats at 37 °C for 1 h. TAS and the enzyme activities were determined spectrophotometrically. The preincubation of brain homogenates with mix. A or mix. B resulted in a decrease of TAS to 30% ( P<0.01), while the presence of Cys or GSH increased TAS to 20% ( P<0.01) and 60% ( P<0.001), respectively. The antioxidants reversed the inhibited Na +,K +-ATPase by mix. A or mix. B and the stimulated Mg 2+-ATPase by mix. B to control values, whereas no effect was observed on the enormously activated Mg 2+-ATPase by mix. A. Conclusions: (a) Gal and its derivatives may produce free radicals in the suckling rat brain, reported for first time, (b) Na +,K +-ATPase inhibition and Mg 2+-ATPase activation are probably due to the oxidative stress from the above compounds, (c) Cys or GSH could play a protective role reversing the inhibited Na +,K +-ATPase toward normal in in vitro galactosaemia and (d) the addition of the above antioxidants may reduce the consequences of brain Mg 2+-ATPase activation by Gal and Galtol in galactokinase deficiency galactosaemia.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.