Factors Affecting Hepatic Glycolysis and Some Changes That Occur During Development

Abstract

1. Glycolysis by the supernatant fraction of homogenates of liver from guinea pigs and rats at various stages of development (foetal, newborn and adult) has been examined in a suitably fortified medium by measurement of inorganic phosphate uptake and production of lactate and glycerol 1-phosphate. 2. Starting with glucose as substrate, two rate-determining steps in glycolysis occur at the stages of glucose phosphorylation and the phosphofructokinase reaction in liver tissue from animals of all ages. Effects of the post-natal development of glucokinase are recorded. 3. The appearance of microsomal glucose 6-phosphatase activity around birth has an effect on glycolysis owing to competition for glucose 6-phosphate. 4. A stimulating effect of the nuclear fraction, especially from foetal liver, on glycolysis by the supernatant fraction is interpreted as being due to stimulation by adenosine-triphosphatase activity at the 3-phosphoglycerate-kinase stage.

Effects of Growth Retardation and Asphyxia on Brain Electrolytes and on Glycolysis in Developing Rats

“…The rate of lactate formation from glucose or glucose 6-phosphate was determined according to the method of Lea and Walker [13] using a 10% (w/v) homogenate prepared in ice-cold 0.32 M sucrose-1 mM ethylenediaminetetraacetic acid (pH 7.4). ATP (1.0 mM) and nicotinamide adenine dinucleotide (1.0 HIM) were included in the incubation medium and lactate was estimated using lactate dehydrogenase [25].…”

Glycolytic Enzymes in the Normal Human Term Placenta

“…The frequency of fetal growth retardation is 1.1-4% of all pregnancies in Middle Europe [24], An impaired function of the placenta is brought up as a leading factor by some authors [4,26], but it may not be justified to speak of chronic placental failure in all cases of fetal growth retardation [13]. Our investigations may help to improve the accuracy of this hitherto ill defined term.…”

Inhibition of Glycolytic Enzymes of Rat Liver and Hepatomas by Free Fatty Acids

“…The concentrations of laurate required to decrease lactate production by a half with normal liver and 3924-A hepatoma preparations were approximately 2.5 mM and 1.5 mM respectively. Experiments on lactate production were performed with cytosol fractions because these were previously found with normal adult liver to give greater rates than with whole homogenates [10]. However, when the rates of lactate production by whole homogenates and cytosol fractions of hepatoma 3924-A preparations were compared a greater rate was observed with the whole homogenates (table IX).…”