Lactate fasting state

Reference values are given according to age, fed state, fasting state, diet and nutritional status (Table 1.4.6). Figure 1.4.4 shows the evolution of KB level as a function of fasting time and age [4, 17]. The reference values for lactate/creatinine/pyruvate are as follows ... 

Table 1.4.6 Reference values for blood lactate, pyruvate, ACAC and according to age, fed state and fasting state. L P lactate-.pyruvate ratio...

The acidosis was treated by intravenous infusion of bicarbonate, and he recovered consciousness. Over the next few days he continued to show signs of acidosis (rapid respiration), and even after a meal he showed ketonuria. His plasma lactate, pyruvate and ketones remained high plasma glucose was in the low normal range and his plasma insulin was normal both in the fasting state and after an oral glucose load. 

Similar studies of the enzyme from pig skeletal muscle have been reported 175,183). In the earlier work, a fast burst of NADH formation in the dead-time of the apparatus was observed, equal in amplitude to the active center concentration at pH 8.0, but smaller at lower pH values. The suggestion that slow isomerization of the ternary product complex before pyruvate release may be the step responsible for the low steady-state maximum rate of lactate oxidation seems to be inconsistent with the full burst observed at pH 8.0, since it might be expected to result in partial equilibration of the reactant and product ternary complexes. Direct studies of the oxidation of E-NADH by pyruvate at pH 9.0 did indicate that reverse hydride transfer from NADH to pyruvate is indeed fast, but the absence of a deuterium isotope effect suggested that the observed rate constant of 246 sec, equal to the maximum steady-state rate of pyruvate reduction, may reflect an isomerization of the ternary complex preceding even faster hydride transfer. More recent studies 183) with improved techniques, however, appear to indicate no burst of enzyme-bound NADH formation preceding the steady-state phase of lactate oxidation at pH 8.0. On the basis of stopped-flow studies of lactate oxidation in the presence of oxamate, which forms a dead-end complex with E-NADH and can serve as an indicator of the rate of formation... 

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