PubMed2001
Whether or not to apply nutritional pretreatment and how to do so are controversial issues with respect to the liver about to undergo aggressive intervention. We studied the effects of glucose loading on the viability of hepatocytes that were subsequently exposed to the inhibitors of carbohydrate metabolism, potassium cyanide (KCN) and iodoacetic acid (IAA). After rat hepatocytes were cultured for 24 hours in Leibovitz's L-15 medium containing 0, 10, 20, and 30 mmol/L glucose, the medium was replaced with modified Hanks-HEPES buffer with or without 2.5 mmol/L KCN or 0.5 mmol/L IAA. Lactate dehydrogenase (LDH) activity, lactate concentration, and pH of the supernatant were measured after 0, 2, 4, and 6 hours of exposure to KCN and after 0, 20, 40, and 60 minutes of exposure to IAA. Glycogen and adenosine triphosphate (ATP) contents in the hepatocytes were measured simultaneously. Hepatocytes cultured with various concentrations of glucose for 24 hours stored levels of glycogen in proportion to the glucose concentration in the culture medium without any significant difference in viability. The hepatocytes cultured with higher glucose concentrations maintained a higher ATP content and released less LDH and more lactate, and the pH decreased in the supernatant during exposure to KCN. Conversely, hepatocytes cultured with lower glucose concentrations maintained a higher ATP content and released less LDH during exposure to IAA. In conclusion, prior glucose loading appears to be beneficial for hepatocytes if oxidative phosphorylation is to be inhibited, whereas withholding glucose appears to be beneficial if glycolysis is to be inhibited.