Effect of various oxygen concentrations on the ATP content in isolated hepatocytes of rats adapted and nonadapted to hypoxia

L. D. Luk'yanova; A. M. Dudchenko; V. V. Belousova

doi:10.1007/bf02445726

Interactions of dietary fat and 2,5-anhydro-d-mannitol on energy metabolism in isolated rat hepatocytes

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00159.2001 ◽

2002 ◽

Vol 282 (3) ◽

pp. R715-R720 ◽

Cited By ~ 9

Author(s):

Hong Ji ◽

Grazyna Graczyk-Milbrandt ◽

Mary D. Osbakken ◽

Mark I. Friedman

Keyword(s):

Oxygen Consumption ◽

Rat Hepatocytes ◽

Isolated Hepatocytes ◽

Metabolic Effects ◽

Atp Content ◽

Isolated Rat Hepatocytes ◽

Palmitate Oxidation ◽

Low Carbohydrate ◽

Lower Oxygen ◽

Hepatocyte Metabolism

The fructose analog 2,5-anhydro-d-mannitol (2,5-AM) stimulates feeding in rats by reducing ATP content in the liver. These behavioral and metabolic effects occur with rats fed a high-carbohydrate/low-fat (HC/LF) diet, but they are prevented or attenuated when the animals eat high-fat/low-carbohydrate (HF/LC) food. To examine the metabolic bases for this effect of diet, we assessed the actions of 2,5-AM on ATP content, oxygen consumption, and substrate oxidation in isolated hepatocytes from rats fed one of the two diets. Compared with cells from rats fed the HC/LF diet (“HC/LF” cells), cells from rats fed the HF/LC diet (“HF/LC” cells) had similar ATP contents but lower oxygen consumption, decreased fructose, and increased palmitate oxidation. 2,5-AM did not decrease ATP content or oxygen consumption in HF/LC cells as much as it did in HC/LF hepatocytes, and it only affected fructose and palmitate oxidation in HC/LF cells.31P-NMR spectroscopy indicated that differences in phosphate trapping accounted for differences in depletion of ATP by 2,5-AM. These results suggest that intake of the HF/LC diet prevents the eating response and attenuates the decline in liver ATP by shifting hepatocyte metabolism to favor fat over carbohydrate as an energy-yielding substrate.

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NH4+ metabolism and the intracellular pH in isolated perfused rat liver

Biochemical Journal ◽

10.1042/bj2930667 ◽

1993 ◽

Vol 293 (3) ◽

pp. 667-673 ◽

Cited By ~ 5

Author(s):

J Zange ◽

J Gronczewski ◽

A W H Jans

Keyword(s):

Intracellular Ph ◽

Rat Liver ◽

Isolated Hepatocytes ◽

Isolated Perfused Rat Liver ◽

Small Range ◽

Perfused Rat Liver ◽

Atp Content ◽

Intracellular Acidification ◽

Subsequent Conversion ◽

Intracellular Alkalinization

The effects of NH4+ on the intracellular pH (pHi) and on the ATP content in isolated perfused rat liver were studied by 31P n.m.r. spectroscopy. In the initial phase of perfusion an average pHi of 7.29 +/- 0.04 was estimated. The presence of low (0.5 mmol/l) and high (10 mmol/l) doses of NH4Cl induced significant intracellular acidification by -0.06 +/- 0.03 and -0.11 +/- 0.03 pH unit respectively. This effect was in contrast with the transient intracellular alkalinization observed in preliminary studies on isolated hepatocytes, which was caused by a passive entry of NH3 by non-ionic diffusion and subsequent conversion into NH4+. During application of 0.5 mmol/l NH4Cl the liver released 0.54 +/- 0.06 mumol of urea/min per g into the perfusate. When the intracellular availability of HCO3- was decreased by acetazolamide (0.5 mmol/l) or by removal of HCO3- from the perfusion medium, the decrease in pHi by NH4Cl application was significantly lower than under control conditions. Furthermore, synthesis of urea was significantly inhibited by the decrease in intracellular HCO3-. Under these conditions, 10 mmol/l NH4Cl caused the transient alkalinization that was expected because of the passive uptake of uncharged NH3. Therefore, it is concluded that the intracellular acidification induced by NH4Cl is caused by the continuous utilization of intracellular HCO3- via the synthesis of urea. This metabolic effect on pHi dominates the effects of passive NH3 entry. The rate of urea formation depends on continuous efflux of H+, which is strictly limiting the degree of intracellular acidification within a small range. If the extrusion of H+ by the Na+/H+ exchanger was inhibited by amiloride (0.5 mmol/l) during the NH4Cl application, the decrease in pHi was amplified and the formation of urea was significantly inhibited. The application of NH4Cl at 0.5 or 10 mmol/l decreased the ATP content by 11% or 22% respectively.

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Mitochondrial and cytosolic ATP/ADP ratios in rat liver in vivo

Biochemical Journal ◽

10.1042/bj2000405 ◽

1981 ◽

Vol 200 (2) ◽

pp. 405-408 ◽

Cited By ~ 80

Author(s):

W D Schwenke ◽

S Soboll ◽

H J Seitz ◽

H Sies

Keyword(s):

Rat Liver ◽

Oxygen Supply ◽

Isolated Hepatocytes ◽

Perfused Liver ◽

Mitochondrial Matrix ◽

Atp Content ◽

Anaesthetized Rats

The ratio of ATP content/ADP content in livers from unanaesthetized fed rat was 0.9 in the mitochondrial matrix and 6.9 in the cytosol; the values for starved (48 h) animals were 1.0 and 5.9 respectively. The mitochondrial ratios observed in unanaesthetized animals were higher than in haemoglobin-free-perfused liver and lower than in isolated hepatocytes. Possible reasons for these differences may be related to oxygen supply and/or other factors. Further, data from anaesthetized rats with the liver exposed are given: mitochondrial ATP/ADP ratios were decreased with pentobarbital, but less so with ketamine as narcotic agent.

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Mitochondrial and cytosolic ATP/ADP ratios in isolated hepatocytes. A comparison of the digitonin method and the non-aqueous fractionation procedure

Biochemical Journal ◽

10.1042/bj1920951 ◽

1980 ◽

Vol 192 (3) ◽

pp. 951-954 ◽

Cited By ~ 29

Author(s):

S Soboll ◽

T P M Akerboom ◽

W D Schwenke ◽

R Haase ◽

H Sies

Keyword(s):

Isolated Hepatocytes ◽

Perfused Liver ◽

Mitochondrial Matrix ◽

Atp Content ◽

Isolated Cells ◽

Fractionation Procedure ◽

Biochemical Difference ◽

Methodological Artifact

The ratio of ATP content/ADP content in the mitochondrial matrix was found to be 2.07 +/- 0.21 and 2.26 +/- 0.22 as determined with six different preparations of isolated hepatocytes subfractionated with the digitonin and non-aqueous-fractionation procedures, respectively. In contrast, the mitochondrial matrix ATP/ADP determined with isolated haemoglobin-free perfused liver by using the non-aqueous-fractionation procedure was about 0.2, whereas the cytosolic values obtained with isolated cells and with the intact organ were similar. It is concluded that the relatively higher ATP/ADP ratio in the mitochondrial matrix of isolated hepatocytes represents a biochemical difference due to properties of the model rather than a methodological artifact.

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Effects of Analgesics and Related Compounds on Renal Metabolism in Rats

Clinical Science ◽

10.1042/cs0530485 ◽

1977 ◽

Vol 53 (5) ◽

pp. 485-492 ◽

Cited By ~ 1

Author(s):

J. D. Tange ◽

B. D. Ross ◽

J. G. G. Ledingham

Keyword(s):

Atp Synthesis ◽

Isolated Hepatocytes ◽

Significant Inhibition ◽

Metabolic Effects ◽

Atp Content ◽

Renal Metabolism ◽

Main Site ◽

Glucose Synthesis ◽

Renal Tubular

1. The metabolic effects of p-aminophenol have been compared with those of paracetamol and other analgesics in studies of rat liver and kidney in vitro. 2. p-Aminophenol injected into rats inhibited gluconeogenesis from lactate in renal cortical tubules, but not in isolated hepatocytes, and reduced kidney ATP content without affecting the ATP content of liver. Perfused kidneys from rats previously injected with p-aminophenol showed a 50% reduction of ATP content, severe inhibition of Na+ reabsorption and reduction of inulin clearance without significant inhibition of gluconeogenesis from lactate. 3. Paracetamol, p-phenetidine, phenazone and aspirin, when given intravenously to rats, had no effect on renal tubular glucose synthesis from lactate or pyruvate. Paracetamol and aspirin both slightly inhibited renal glucose synthesis from several different substrates when added directly to tubules. 4. Paracetamol (4 mmol/l) inhibited glucose synthesis from lactate and other substrates by 50% or more in isolated hepatocytes. Glucose synthesis from lactate was inhibited 30% by concentrations of paracetamol as low as 0–5 mmol/l. 5. These results indicate that p-aminophenol is a potent inhibitor of proximal tubular function, with its main site of action the inhibition of ATP synthesis and energy production, and they confirm the primary hepatotoxic effect of paracetamol.

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