NADH_NAD redox state of cytoplasmic glycolytic

NADH_NAD redox state of cytoplasmic glycolytic

Barron, John T., Liping Gu, and Joseph E. Parrillo.
NADH/NAD redox state of cytoplasmic glycolytic compartments
in vascular smooth muscle. Am J Physiol Heart Circ
Physiol 279: H2872–H2878, 2000.—The cytoplasmic NADH/
NAD redox potential affects energy metabolism and contractile
reactivity of vascular smooth muscle. NADH/NAD redox
state in the cytosol is predominately determined by glycolysis,
which in smooth muscle is separated into two functionally
independent cytoplasmic compartments, one of which
fuels the activity of Na1-K1-ATPase. We examined the effect
of varying the glycolytic compartments on cystosolic NADH/
NAD redox state. Inhibition of Na1-K1-ATPase by 10 mM
ouabain resulted in decreased glycolysis and lactate production.
Despite this, intracellular concentrations of the glycolytic
metabolite redox couples of lactate/pyruvate and glycerol-
3-phosphate/dihydroxyacetone phosphate (thus NADH/
NAD) and the cytoplasmic redox state were unchanged. The
constant concentration of the metabolite redox couples and
redox potential was attributed to 1) decreased efflux of lactate
and pyruvate due to decreased activity of monocarboxylate
B-H1 transporter secondary to decreased availability of
H1 for cotransport and 2) increased uptake of lactate (and
perhaps pyruvate) from the extracellular space, probably
mediated by the monocarboxylate-H1 transporter, which was
specifically linked to reduced activity of Na1-K1-ATPase. We
concluded that redox potentials of the two glycolytic compartments
of the cytosol maintain equilibrium and that the cytoplasmic
NADH/NAD redox potential remains constant in the
steady state despite varying glycolytic flux in the cytosolic
compartment for Na1-K1-ATPase…

Profile photo of nadhwiki

nadhwiki has written 69 articles

Leave a Reply