Mechanisms of hepatic lactate uptake were studied in the gulf toadfish, Opsanus beta by following the accumulation of [C]lactate by isolated hepatocytes in vitro. Uptake rates were linear for up to 5 s at external lactate concentrations of 1 and 20mmoll~'. 5-s uptake rates for several concentrations in the physiological range (i.e. 0-2-20mmoll") yielded a linear double reciprocal plot (l/v vs l...

Lactic acid is produced as an end product of glycolysis in rainbow trout white muscle following exhaustive exercise. The metabolically produced lactic acid causes an intramuscular acidosis that must be cleared, either via net transport out of the muscle or by conversion to glycogen, thereby replenishing the muscle energy store. Trout muscle has been shown to retain lactate and utilise it as a s...

Rainbow trout ( Oncorhynchus rnykiss ) retain the majority of lactate produced during exhaustive exercise within the white muscle. Previous studies have suggested that this retention is partiaiiy via a reuptake of released lactate. The purpose of this work was to study lactate uptake using trout white muscle sarcolemmai vesicles. Through modifications to the original mammalian giant vesicle tec...

This study was undertaken to quantitatively account for the metabolic disposal of lactate in skeletal muscle exposed to an elevated lactate concentration during rest and mild-intensity contractions. The gastrocnemius plantaris muscle group (GP) was isolated in situ in seven anesthetized dogs. In two experiments, the muscles were perfused with an artificial perfusate with a blood lactate concent...

In all vertebrates, including humans, the L-lactate form is by far the most abundant and pathophysiologically significant, and it is this form that is specifically measured by the lactate sensors in blood gas analyzers and indeed all routine methods used to measure lactate in the clinical laboratory. The main focus of this brief review is physiological and pathological aspects that distinguish ...

Blood lactate concentrations reflect the balance between lactate production and clearance. During glycolysis in resting state, most glucose is converted to pyruvate. Pyruvate is metabolized through the aerobic pathway, to acetyl-CoA by pyruvate dehydrogenase (PDH) to enter the tricarboxylic acid cycle that is the main source of energy for cellular metabolism. In times of stress, tissue oxygen (...

Increased glucose uptake and accumulation of lactate, even under normoxic conditions (i.e., aerobic glycolysis or the Warburg Effect), is a common feature of cancer cells. This phenomenon clearly indicates that lactate is not a surrogate of tumor hypoxia. Tumor lactate can predict for metastases and overall survival of patients, as shown by several studies of different entities. Metastasis of t...