Inhibition of gluconeogenesis in isolated rat hepatocytes after chronic treatment with phenobarbital.

Content Provider	Semantic Scholar
Author	Argaud, D. Halimi, Serge Catelloni, F. Leverve, Xavier
Copyright Year	1991
Abstract	Gluconeogenesis was studied in hepatocytes isolated from phenobarbital-pretreated rats fasted for 24 h. In closed vial incubations, glucose production from lactate (20 mmol/l) and pyruvate (2 mmol/l), alanine (20 mmol/l) or glutamine (20 mmol/l) was suppressed by about 30-45%, although glycerol metabolism was not affected. In hepatocytes perifused with lactate and pyruvate (ratio 10:1), glucose production was inhibited by 50%, even at low gluconeogenic flux. From the determination of gluconeogenic intermediates at several steady states of gluconeogenic flux, we have found a single relationship between phosphoenolpyruvate and the rate of glucose production (Jglucose), and two different curves between cytosolic oxaloacetate and Jglucose in controls and in phenobarbital-pretreated hepatocytes. By using 3-mercaptopicolinate to determine the flux control coefficient of phosphoenolpyruvate carboxykinase we found that phenobarbital pretreatment led to an increase in this coefficient from 0.3 (controls) to 0.8 (phenobarbital group). These observations were confirmed by the finding that the activity of phosphoenolpyruvate carboxykinase was decreased by 50% after phenobarbital treatment. Hence we conclude that the inhibitory effect of phenobarbital on gluconeogenesis is due, at least partly, to a decrease in the flux through phosphoenolpyruvate carboxykinase.
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Alternate Webpage(s)	http://www.biochemj.org/content/ppbiochemj/280/3/663.full.pdf
PubMed reference number	1764030v1
Volume Number	280
Part	3
Journal	The Biochemical journal
Language	English
Access Restriction	Open
Subject Keyword	ATP-Dependent Phosphoenolpyruvate Carboxykinase Alanine Coefficient Gluconeogenesis Glucose Glutamine Glycerin Lactic acid Millimole per Liter Oxaloacetates Phenobarbital Phosphoenolpyruvate carboxykinase deficiency Pyruvates glycerol metabolic process
Content Type	Text
Resource Type	Article