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Protein Binding of NADH on Chemical Preconditioning
Author(s) -
Huber Roman,
Büchner Maren,
Li Hongge,
Schlieter Martin,
Speerfeld Anne Dorte,
Riepe Matthias W.
Publication year - 2000
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1046/j.1471-4159.2000.0750329.x
Subject(s) - hypoxia (environmental) , in vivo , chemistry , hippocampal formation , fluorescence , metabolism , nad+ kinase , biophysics , biochemistry , medicine , endocrinology , biology , oxygen , enzyme , physics , microbiology and biotechnology , organic chemistry , quantum mechanics
: Chemical preconditioning, an emerging neuroprotective strategy described in recent years, results in preserved energy metabolism during hypoxia via yet unknown mechanisms. The hypoxic increase of NADH content is attenuated by preconditioning. The goal of the present study was to investigate whether attenuation of the hypoxic NADH increase is due to a shift between free and protein‐bound NADH. NADH in solution has a fluorescence maximum at 469.2 nm. In untreated mouse hippocampal slices, λ control onset is 456.2 ± 5.3 nm in CA1 (mean ± SD ; p < 0.01 vs. solution) and 454.6 ± 6.1 nm in CA3 [ p < 0.01 vs. solution, not significant (NS) to λ control onset in CA1]. In slices prepared from animals pretreated in vivo with 20 mg/kg 3‐nitropropionate, λ preconditioning onset is 439.2 ± 5.0 nm ( p < 0.001 vs. control) in CA1 and 434.2 ± 6.4 nm in CA3 ( p < 0.001 vs. control ; NS to λ preconditioning onset in CA1). In controls, the fluorescence maximum shifts to λ control hypoxia 458.2 ± 1.3 nm in CA1 (NS vs. onset) and 456.0 ± 3.6 nm in CA3 (NS vs. onset). On preconditioning with 3‐nitropropionate, λ preconditioning hypoxia shifts to 446.4 ± 4.3 nm in CA1 ( p < 0.03 vs. onset) and 438.6 ± 6.9 nm in CA3 ( p < 0.03 vs. onset). Posthypoxic decay of free and protein‐bound NADH is diminished after preconditioning. We conclude that the free NADH level is reduced on an increase of hypoxic tolerance by chemical preconditioning. Reduction of free NADH content is maintained during hypoxia after preconditioning.