Modeling cerebral arteriovenous lactate kinetics after intravenous lactate infusion in the rat.

Venous-arterial lactate differences across the brain during lactate infusion in rats were studied, and the fate of lactate was described with a mathematical model that includes both cerebral and extracerebral kinetics. Ultrafiltration was used to sample continuously and simultaneously arterial and venous blood. Subsequent application of flow injection analysis and biosensors allowed the measurement of glucose and lactate concentrations every minute.

The potential of biosensor technology in clinical monitoring and experimental research.

Glucose or lactate biosensors are very useful for monitoring metabolism. Continuous monitoring of glucose is for example very important in diabetic patients. The measurement of lactate, a marker for oxygen deficiency, is used in the intensive care unit to monitor the patients' condition.

Quantitative on-line monitoring of cellular glucose and lactate metabolism in vitro with slow perfusion.

An on-line in vitro perfusion technique is described that allows the continuous quantification of cellular glucose metabolism in vitro. Using biosensor technology, we measure glucose and lactate metabolism at a minute-to-minute time resolution for periods up to several days. The application of our perfusion-detection technique for in vitro monitoring is demonstrated in a wide variety of cells, including primary neuronal and astroglia cultures, yeast cells, and human lymphocytes.

Evidence for a lactate pool in the rat brain that is not used as an energy supply under normoglycemic conditions.

Lactate derived from glucose can serve as an energy source in the brain. However, it is not certain how much lactate, directly taken from the blood circulation, may replace glucose as an energy source. This study aimed to estimate the uptake, release, and utilization of lactate entering the brain from the blood circulation.

Utilization of in vivo ultrafiltration in biomedical research and clinical applications.

Ultrafiltration (UF) is a filtrate selection method with a wide range of biomedical and clinical applications, including detoxification of blood in hemodialysis and peritoneal dialysis. New is, however, the use of UF as a convenient in vivo sampling method that, for example, has been used in diabetics. Ultrafiltration avoids complicated and time-consuming recovery calculations that are necessary when using in vivo microdialysis, as recoveries of low molecular weight molecules are near 100%.

Quantitative on-line monitoring of hippocampus glucose and lactate metabolism in organotypic cultures using biosensor technology.

Quantitative glucose and lactate metabolism was assessed in continuously perfused organotypic hippocampal slices under control conditions and during exposure to glutamate and drugs that interfere with aerobic and anaerobic metabolism. On-line detection was possible with a system based on slow perfusion rates, a half-open (medium/air interface) tissue chamber and a flow injection analytic system equipped with biosensors for glucose and lactate. Under basal conditions about 50% of consumed glucose was converted to lactate in hippocampal slice cultures.