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Studies on the mechanism by which glutamine and heat shock increase lactate synthesis by l929 cells in the presence of insulin
Author(s) -
Lanks Karl W.
Publication year - 1986
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.1041290317
Subject(s) - glutamine , glycolysis , stimulation , biochemistry , cytosol , shock (circulatory) , mitochondrion , insulin , chemistry , metabolism , biology , medicine , endocrinology , amino acid , enzyme
Both glutamine and heat shock increase lactate production in the L929 cell system, Glutamine is now shown to increase hexose uptake in the presence of insulin, to inhibit pyruvate oxidation, and to provide reducing equivalents to the cytosolic compartment. The relative contribution of these processes to lactate production depends on the availability of pyruvate. When ample pyruvate is available from the culture medium, stimulation of lactate synthesis by glutamine and heat shock is transaminase dependent, suggesting that shuttling of reducing equivalents from mitochondria to cytoplasm is involved. In the absence of medium pyruvate, stimulation of glycolysis by both glutamine and heat shock is largely responsible for increased lactate synthesis. None of the observed effects of glutamine appears to be sufficient to explain the observed stimulation of glycolysis.