Comparison of the effects of adenine-ribose with adenosine for maintenance of ATP concentrations in 5-day hypothermically perfused dog kidneys

The quality of preservation of kidneys is dependent upon a number of factors, one of which may be the concentration of adenine nucleotides in the tissue during long-term perfusion preservation. In this study we have investigated how adenine (5 mM) and ribose (5 mM) in combination affect the concentration of adenine nucleotides in dog kidney cortical tissue after 5 days of continuous hypothermic perfusion preservation. These results were compared to kidneys perfused with adenosine and without any added purine precursors of adenine nucleotide synthesis. Additionally, we investigated how these conditions affected renal tissue slice function after 5 days of preservation and how adenine plus ribose affected renal function after autotransplantation in the dog. Adenosine is nearly completely degraded during 5 days of perfusion but there was little loss of adenine (10%). The adenosine triphosphate concentration in kidney cortical tissue was higher in adenine/ribose-perfused kidneys (1.41 +/- 0.19 mumol/g) than in adenosine-perfused kidneys (0.71 +/- 0.1 mumol/g) after 5 days of preservation. Tissue slices prepared from kidneys preserved in the presence of adenine plus ribose were metabolically more functional (slice volume control and electrolyte pump activity) than slices from adenosine-perfused kidneys. Adenine plus ribose had no detrimental effects on kidneys preserved for 3 days as tested in the autotransplant model but did not yield successful 5-day preservation. Because of some potentially detrimental factors in using adenosine as an adenine nucleotide synthesis precursor, we have now switched to the combination of adenine and ribose for perfusion preservation of kidneys both in the laboratory and in the clinic.     

Energy metabolism following prolonged hepatic cold preservation: benefits of interrupted hypoxia on the adenine nucleotide pool in rat liver.

The ability of brief hypothermic reperfusion (HtR) to restore hepatic energy metabolism following periods of cold hypoxic preservation was studied in isolated rat livers after storage times of 5, 10, and 24 h. In addition, investigations were performed on the effects of HtR used to restore liver oxidative metabolism in the middle of a prolonged (24 h) hypoxic preservation period. A histidine-lactobionate-raffinose solution was used for the initial cold portal flush in all groups. Results showed that cold hypoxia for either 5 or 10 h yielded livers capable of similar recoveries of ATP, energy charge, and total adenine nucleotides, but that HtR after 24 h cold preservation resulted in reduced regeneration of ATP, a lower energy charge, and a fall in tissue adenine nucleotides. When livers were stored for 24 h but subjected to brief HtR after either 5 or 10 h before return to hypoxic storage, improved recoveries of the energy metabolites were seen over those recorded after 24 h hypoxia alone. The fact that these improvements were not due to an improved supply of adenine nucleotide precursors was demonstrated by studying groups which were given HtR with perfusate containing precursors of adenine nucleotides (adenosine, adenine, and inosine) after 24 h cold hypoxia. These data are consistent with the hypothesis that poor metabolic recovery after long-term hepatic cold preservation results more from decreased mitochondrial oxidative phosphorylation than from a lack of precursors for adenine nucleotide resynthesis. In addition, restoring oxidative metabolism at hypothermia for brief periods can to some extent protect final metabolic status after prolonged storage.     

Allopurinol Enhances Adenine Nucleotide Levels and Improves Myocardial Function in Isolated Hypoxic Rat Heart

Allopurinol, a competitive inhibitor of xanthine oxidase, was found to have a protective effect on ischemic myocardium. Its mechanism of action is still controversial. We used Langendorff isolated rat heart preparation to test the hypothesis that allopurinol could maintain a level of the adenine nucleotide pool (ATP, ADP, and AMP) that would protect and improve the functional activity of the heart during a period of hypoxia. Hearts were initially perfused for 30 min until steady state was attained. This was followed by 20 min of experimental perfusion divided into 5 min of control perfusion followed by 15 min of hypoxic perfusion with or without allopurinol in the perfusate. Hearts were quick-frozen and enzymatically analyzed for adenine nucleotides and creatine phosphate at the end of the hypoxic period. Left ventricular pressure, heart rate, and coronary flow were measured in all preparations. Allopurinol (0.1 mM) treated hearts had greater levels of ATP (12.3 ± 0.8 vs. 9.3 ± 0.8 µmol/g dry weight; p < 0.01). This improvement occurred in the presence as well as the absence of glucose. Total adenine nucleotides improved from 17 ± 1 to 20.3 ± 2.4 µmol/g dry weight (p < 0.01). This improvement also occurred in the presence as well as in the absence of glucose in the perfusate. It also improved cell energy state significantly in the presence as well as the absence of glucose. There was insignificant change in creatine phosphate. Allopurinol improved left ventricular pressure from 38 ± 7% to 55 ± 9% (p < 0.002) in the presence of glucose and from 8 ± 3% to 27 ± 6.3% (p < 0.001) in the absence of glucose. Coronary flow improved from 110 ± 5% to 120 ± 8% (p < 0.04) in the presence of glucose. These results support the suggestion that allopurinol at 0.1 mM exerts its protective effect on rat heart during hypoxia by enhancing the adenine nucleotide pool.     

Effects of increased heart work on glycolysis and adenine nucleotides in the perfused heart of normal and diabetic rats

1. In the isolated perfused rat heart, the contractile activity and the oxygen uptake were varied by altering the aortic perfusion pressure, or by the atrial perfusion technique (;working heart'). 2. The maximum increase in the contractile activity brought about an eightfold increase in the oxygen uptake. The rate of glycolytic flux rose, while tissue contents of hexose monophosphates, citrate, ATP and creatine phosphate decreased, and contents of ADP and AMP rose. 3. The changes in tissue contents of adenine nucleotides during increased heart work were time-dependent. The ATP content fell temporarily (30s and 2min) after the start of left-atrial perfusion; at 5 and 10min values were normal; and at 30 and 60min values were decreased. ADP and AMP values were increased in the first 15min, but were at control values 30 or 60min after the onset of increased heart work. 4. During increased heart work changes in the tissue contents of adenine nucleotide and of citrate appeared to play a role in altered regulation of glycolysis at the level of phosphofructokinase activity. 5. In recirculation experiments increased heart work for 30min was associated with increased entry of [(14)C]glucose (11.1mm) and glycogen into glycolysis and a comparable increase in formation of products of glycolysis (lactate, pyruvate and (14)CO(2)). There was no major accumulation of intermediates. Glycogen was not a major fuel for respiration. 6. Increased glycolytic flux in Langendorff perfused and working hearts was obtained by the addition of insulin to the perfusion medium. The concomitant increases in the tissue values of hexose phosphates and of citrate contrasted with the decreased values of hexose monophosphates and of citrate during increased glycolytic flux obtained by increased heart work. 7. Decreased glycolytic flux in Langendorff perfused hearts was obtained by using acute alloxan-diabetic and chronic streptozotocin-diabetic rats; in the latter condition there were decreased tissue contents of hexose phosphates and of citrate. There were similar findings when working hearts from streptozotocin-diabetic rats with insulin added to the medium were compared with normal hearts. 8. The effects of insulin addition or of the chronic diabetic state could be explained in terms of an action of insulin on glucose transport. Increased heart work also acted at this site, but in addition there was evidence for altered regulation of glycolysis mediated by changes in tissue contents of adenine nucleotides or of citrate.     

Effects of ethacrynic acid and furosemide on phosphorylation reactions of kidney mitochondria. Inhibition of the adenine nucleotide translocase.

Previous reports that ethacrynic acid and furosemide diminish mitochondrial P : O ratios and reduce (Na+ + K+)-ATPase activity suggested that these diuretics may inhibit mitochondrial phosphorylation reactions. This possibility was initially studied by determining the effects of ethacrynic acid and furosemide on [32P]ATP exchange activity of rat kidney mitochondria. Concentrations of both drugs at 10(-4) M or greater, significantly inhibited [32P]ATP exchange. To investigate the mechanism of this inhibition, the effects of ethacrynic acid and furosemide on the ATPase activity of intract mitochondria and sonicated submitochondrial particles were determined. Both diuretics inhibited ATPase activity of intact mitochondria at 10(-4) M. In contrast, ATPase of submitochondrial particles was significantly less susceptible to inhibition by the diuretics. These results suggested that ethacrynic acid anf furosemide inhibit adenine nucleotide transport across the mitochondrial membrane. This was directly tested by determining the effects of the diretics on the mitochondrial adenine nucleotide translocase. At 5-10(-4) M, both ethacrynic acid and furosemide significantly inhibited adenine nucleotide transport. These findings suggest that ethacrynic acid and furosemide may diminish renal tubular solute reabsorption by direct inhibition of adenine nucleotide transport across the mitochondrial inner membrane.     

Adenylate energy charge of rat and human cultured hepatocytes

Summary A simple and rapid method for the assay of adenine nucleotides (ATP, ADP, and AMP) was established to evaluate the adenylate energy charge (ATP+ADP/2)/(ATP+ADP+AMP) of cultured hepatocytes. The effects of inhibitors of glycolysis, fatty acid oxidation, or oxidative phosphorylation on the energy charge were examined. The energy charges of cultured hepatocytes in rats and human were almost identical and were maintained at a high level between 6 and 24 h after changing the media (rat: 0.908±0.008n=9, human: 0.918±0.014n=6, mean ± SD). Inhibition of glycolysis with sodium fluoride or oxidative phosphorylation with antimycin A irreversibly reduced both the adenine nucleotide contents and the energy charge. However, the inhibition of fatty acid oxidation with 2-tetradecylglycidic acid did not affect the nucleotide contents, and the energy charge only decreased transiently to recover within 8 h. When the inhibitor of oxidative phosphorylation was removed, the recovery in the energy charge preceded the recovery in the adenine nucleotide contents. These findings suggest that the adenylate energy charge is a more sensitive measure of the changes in energy metabolism than the adenine nucleotide contents. Furthermore, energy charge regulates adenine nucleotide contents in cultured hepatocytes. It is important to confirm that the high energy charge of the cultured hepatocytes is maintained when these cells are used for metabolic studies.     

Light-Induced Membrane Hyperpolarization and Adenine Nucleotide Levels in Perfused Characean Cells

This study examines the relationship between light-induced membranehyperpolarization and changes in adenine nucleotide levels intonoplast-free characean cells. When cells were perfused witha medium containing 1 mM ATP in the dark, the plasma membranedepolarized, the cytosolic ATP level decreased, and the ADPand AMP levels increased. Under light, the membrane hyperpolarized,the ATP level increased, and the ADP and AMP levels decreased.These changes in the adenine-nucleotide levels could partiallyexplain the membrane hyperpolarization. When cells were perfusedwith a medium containing an ATP-regenerating system consistingof phosphoenolpyruvate and pyruvate kinase, the membrane potentialremained in the hyperpolarized state, the ATP level remainedat a high level and no light-induced hyperpolarization was observed.The intracellular adenine nucleotide levels were also controlledby continuous perfusion. The membrane potential was determinedonly by the adenine nucleotide levels of perfusion media, irrespectiveof the light condition. Chloroplast-free Nitellopsis cells into which isolated Pisumchloroplasts were introduced also showed light-induced membranehyperpolarization. Pretreatment of chloroplasts with dicyclohexylcarbodiimide(DCCD) completely abolished the hyperpolarization with parallelinhibition of photophosphorylation. These results strongly suggestthat changes in adenine nucleotide levels caused by photophosphorylationare responsible for light-induced membrane hyperpolarizationin perfused cells. (Received August 17, 1985; Accepted December 13, 1985)     

Effects of ethacrynic acid and furosemide on phosphory-lation reactions of kidney mitochondria. Inhibition of the adenine nucleotide translocase

Previous reports that ethacrynic acid and furosemide diminish mitochondrial P : O ratios and reduce (Na⁺ + K⁺)-ATPase activity suggested that these diuretics may inhibit mitochondrial phosphorylation reactions. This possibility was initially studied by determining the effects of ethacrynic acid and furosemide on [³²P]ATP exchange activity of rat kidney mitochondria. Concentrations of both drugs at 10⁻⁴ M or greater, significantly inhibited [³²P]ATP exchange. To investigate the mechanism of this inhibition, the effects of ethacrynic acid and furosemide on the ATPase activity of intact mitochondria and sonicated submitochondrial particles were determined. Both diuretics inhibited ATPase activity of intact mitochondria at 10⁻⁴ M. In contrast, ATPase of submitochondrial particles was significantly less susceptible to inhibition by the diuretics. These results suggested that ethacrynic acid and furosemide inhibit adenine nucleotide transport across the mitochondrial membrane. This was directly tested by determining the effects of the diuretics on the mitochondrial adenine nucleotide translocase. At 5 · 10⁻⁴ M, both ethacrynic acid and furosemide significantly inhibited adenine nucleotide transport. These findings suggest that ethacrynic acid and furosemide may diminish renal tubular solute reabsorption by direct inhibition of adenine nucleotide transport across the mitochondrial inner membrane.     

Effects of the differentiating agents sodium butyrate and N-methylformamide on the oxygen enhancement ratio of human colon tumor cells

We have previously shown that chronic adaptation of human tumor cells to the differentiation-inducing agents N-methylformamide (NMF) and sodium butyrate (NAB) increases the sensitivity of oxic cells to graded single doses of X rays. These studies were carried out to define the sensitivity of hypoxic cells after adaptation. Clone A colon tumor cells were grown for three passages in medium containing 170 mM NMF or 2 mM NAB and irradiated in suspension culture, after gassing with either oxygen (60 min) or ultrapure nitrogen (90 min), and complete survival curves were generated. Using the linear-quadratic equation to describe the data, it was found that NMF and NAB produced increased X-ray killing of hypoxic cells. At the 10% level of survival, the dose-modifying factors were about 1.20 and 1.25 for NMF- and NAB-adapted hypoxic cells, respectively, as compared to hypoxic control cells. However, since both oxic and hypoxic cells exhibited increased sensitivity after NMF and NAB adaptation, there was no major change in the oxygen enhancement ratio.     

Consumption of platelets in decompression sickness of rabbits

Platelet behavior was studied in rabbit decompression sickness which was brought about by the exposure to 6 ATA for 40 min (bottom time) followed by rapid decompression. Platelet counts significantly decreased after the decompression. Kinetic studies with 111In-oxine-labeled platelets revealed shortened survivals of circulating platelets, and audioradiograms indicated the accumulation of radioactivity in the lungs after the decompression. Although there was no change in the mode volume of platelets after the decompression, the transient appearance of circulating smaller or fragmented platelets suggested a random overdestruction of platelets. Whole and releasable adenine nucleotide contents of platelets were decreased significantly after the decompression. There were no significant changes in cytoplasmic adenine nucleotide contents. Therefore, in decompression sickness, the circulating platelets behaved similarly to those in acquired storage pool disease. Platelet thrombi were found in the pulmonary arteries, compatible with the accumulation of 111In-oxine-labeled platelets. These findings suggest that circulating air bubbles interact with platelets, causing the platelet release reaction, and these activated platelets participate in the formation of thrombi in experimental decompression sickness.     

Surface biochemical changes accompanying primary infection with Rous sarcoma virus. II. Proteolytic and glycosidase activity and sublethal autolysis

Changes in the cellular adenine nucleotide contents of larval salivary glands of Drosophila hydei as a result of treatments affecting the respiratory metabolism were established and correlated with changes in the activity of four genome loci. The results demonstrate that the activation of the genome loci is not a necessary consequence of a reduction in the ATP level or changes in ADP or AMP levels. Other regulatory mechanisms for the activation of these genome loci are discussed.     

Bovine spermatozoa as anin vitro model for studies on the cytotoxicity of chemicals: effects of chlorophenols

The suitability of ejaculated bovine spermatozoa as an in vitro model for the assessment of the cytotoxic potential of chemicals was evaluated using several endpoints: swimming activity, adenine nucleotide content, membrane integrity and oxygen consumption. A series of chlorophenols inhibited sperm motion (motility and velocity) in a concentration-dependent manner. This could be determined quantitatively and reproducibly by means of videomicrography and automatic computer image analysis. The sperm immobilizing potency increased with increasing chlorination and was positively correlated with lipophilicity. Concentrations which reduced the percentage of moving sperm to 50% of controls ranged from 43 µM for pentachlorophenol (PCP) to 1440 µM for 4-monochlorophenol (4-MCP). Determinations of adenine nucleotides and percentages of viable cells revealed qualitative differences between the action of PCP and the lower chlorinated phenols. While the latter decreased the total adenine nucleotide contents and the percentage of unstained cells in parallel to motion inhibition, no such changes occurred after exposure to immobilizing concentrations of PCP. Penta-, tetra- and trichlorinated phenols stimulated cellular respiration, indicating their uncoupling activity, at concentrations lower than those necessary for motion inhibition. The results indicate that bovine spermatozoa may become a useful in vitro model for the toxicological evaluation of chemicals providing quantitative as well as qualitative data.Abbreviations PCP pentachlorophenol - 2,3,4,5-TCP 2,3,4,5-tetrachlorophenol - 2,4,5-TCP 2,4,5trichlorophenol - 2,4-DCP 2,4-dichlorophenol - 4-MCP 4-monochlorophenol     

Enhancement of X-ray-induced sister chromatid exchanges in hypoxic cells

In these studies we have used wild-type Chinese hamster ovary cells (AA8) and a mutant cell line (UV-41) deficient in excision repair to compare sister chromatid exchange (SCE) induction after X irradiation under oxic and hypoxic conditions. X irradiation of AA8 cells under oxic conditions induced only a slight increase in SCEs, whereas at each dose tested a significantly greater number of SCEs were induced in hypoxic cells. When AA8 cells were X-irradiated and the addition of bromodeoxyuridine (BrdU) was delayed for 20 h to allow DNA lesions to be repaired, the levels of SCEs detected in both oxic and hypoxic cells returned to background levels. X irradiation of UV-41 cells also induced only a slight increase of SCEs in oxic cells, whereas a significant number of SCEs were induced in hypoxic cells. However, in contrast to results with AA8 cells, when hypoxic UV-41 cells were X-irradiated and the addition of BrdU was delayed for 20 h, the number of SCEs remained significantly above background levels. In combination with previous alkaline elution data, these results are consistent with the possibility that DNA-protein crosslinks are responsible for the SCEs induced by X irradiation of hypoxic cells. Irrespective of the mechanism(s) involved, the data presented suggest that the SCE assay may potentially aid in the detection of hypoxic tumor cells.     

The adenine nucleotide translocator in foetal, suckling and adult rat liver mitochondria

The adenine nucleotide content of rat liver mitochondria was shown to increase significantly after birth. On the other hand, it was found that the ligand-binding properties of the adenine nucleotide translocator were essentially the same in foetal, suckling and adult rat liver mitochondria. These results are compatible with the proposal that the accumulation of adenine nucleotides which occurs during mitochondrial biogenesis and maturation is effected by a pathway different from the adenine nucleotide translocator.     

Ischemia decreases the content of the adenine nucleotide translocator in mitochondria of rat kidney

The activity of the adenine nucleotide translocator is decreased at ischemia. Studies were undertaken to elucidate changes in the adenine nucleotide translocator by determining its content in mitochondria of ischemic rat kidney. After 60 min of ischemia, the content of the adenine nucleotide translocator amounted only to about 55%, of that measured in control mitochondria. At the same time, the flux control coefficient was increased. These changes paralled the well-known effects of ischemia: the decrease in oxidative phosphorylation and in adenine nucleotides. It is supposed that the decrease in the adenine nucleotide translocatar content accounts, at least partially, for the ischemia-induced impairment of mitochondria.     

Biochemical and ultrastructural evaluation of isolated rat liver systems perfused with a hemoglobin-free medium

The viability of hemoglobin-free perfused rat liver was examined with respect to several liver functions and to the intactness of subcellular structures under electron microscopic observation. Provided that rat livers were perfused with the oxygenated buffer solution at a flow rate between 3 and 3.5 ml/min per g of liver, all the biochemical parameters measured in the perfused liver system, i.e. the rates of glucose, pyruvate, and lactate production, the rate of oxygen consumption and the tissue contents of adenine nucleotides, were similar to those observed with perfusion systems containing erythrocytes or albumin. The perfused liver showed a sensitive response to norepinephrine, involving a reduction of pyridine nucleotides and enhancements of glucose production and oxygen consumption. On electron microscopic examination, changes in hepatic-structure indicative of hypoxic injury particularly vacuolar degeneration and mitochondrial swelling, were not detected in the liver after 70 min of perfusion; the fact that the fine structure of the hepatocyte was preserved in all parts of the organ confirmed that the supply of oxygen to the perfused liver was sufficient under the conditions employed. From viewpoint of the generally accepted criteria for the viability of perfused liver, therefore, the results confirmed that the perfusion of liver with a hemoglobin- and albumin-free medium is a convenient and reliable tool for biochemical investigation of the reactions occurring in whole liver.     

Radioprotective effect of cysteamine in glutathione synthetase-deficient cells

The radioprotective role of endogenous and exogenous thiols was investigated, with survival as the end-point, after radiation exposure of cells under oxic and hypoxic conditions. Human cell strains originating from a 5-oxoprolinuria patient and from a related control were used. Due to a genetic deficiency in glutathione synthetase, the level of free SH groups, and in particular that of glutathione, is decreased in 5-oxoprolinuria cells. The glutathione synthetase deficient cells have a reduced oxygen enhancement ratio (1.5) compared to control cells (2.7). The radiosensitivity was assessed for both cell strains in the presence of different concentrations of an exogenous radioprotector:cysteamine. At concentrations varying between 0.1 and 20 mM, cysteamine protected the two cell strains to the same extent when irradiated under oxic and hypoxic conditions. The protective effect of cysteamine was lower under hypoxia than under oxic conditions for both cell strains. Consequently, the oxygen enhancement ratio decreased for both cell strains when cysteamine concentration increased. These results suggest that cysteamine cannot replace endogenous thiols as far as they are implicated in the radiobiological oxygen effect.     

Determination of the enantiomerization energy barrier of some 3-hydroxy-1,4-benzodiazepine drugs by supercritical fluid chromatography

In this study, nucleotide adsorption-desorption behaviour of boronic acid-carrying uniform, porous particles was investigated. The particles were produced by a "multi-step microsuspension polymerization" in the form of poly(styrene-vinylphenyl boronic acid-divinylbenzene) terpolymer. In the first step of the production method, uniform polystyrene latex particles (6.2 microm in size) were obtained by dispersion polymerization. These particles were first swollen by a low molecular mass organic agent (i.e. dibutylphthalate, DBP) and then by a monomer mixture including styrene (S), 4-vinylphenyl boronic acid (VPBA) and divinylbenzene (DVB). The particle uniformity was protected in both swelling stages by adjusting DBP/polystyrene latex and monomer mixture/polystyrene latex ratios. Polymerization of the monomer mixture in the swollen seed particles provided boronic acid-carrying uniform, porous particles 11-12 microm in size. To have uniform particles with different porosities and boronic acid contents, the feed concentration of boronic acid-carrying monomer and the monomer/seed latex ratio were changed. The particles were tried as sorbent for the adsorption of a model nucleotide (i.e., beta-nicotinamide adenine dinucleotide, beta-NAD). In the beta-NAD adsorption experiments, the maximum equilibrium adsorption was obtained at pH 8.5 which was very close to pKa of boronic acid. The incorporation of boronic acid functionality provided a significant increase in the beta-NAD adsorption. In contrast to plain poly(styrene-co-divinylbenzene) particles, four-fold higher beta-NAD adsorption was obtained with the boronic acid functionalized particles. Beta-NAD was desorbed from the particles with the yields higher than 90% by weight.     

Pulmonary microvascular endothelial cells constitutively release xanthine oxidase.

The generation of oxidants in reperfused ischemic tissues by xanthine oxidase (XO) may contribute to tissue damage. We exposed bovine pulmonary microvascular endothelial (BPMVE) cells to hypoxia and subsequent reoxygenation and examined alterations in intracellular and extracellular XO activities. BPMVE cells incubated 24 h under hypoxic conditions (less than 1% O2) showed a twofold increase in intracellular xanthine dehydrogenase activity and a smaller increase in intracellular XO activity compared to normoxic BPMVE. Both normoxic and hypoxic BPMVE cells constitutively released XO activity into their culture media. Incubation of hypoxic or normoxic BPMVE cells with oxygenated medium (95% O2) stimulated the release of XO activity into the extracellular medium within 5 min. The XO activity could not be detected in the oxygenated medium after 60 min incubation with 95% O2. These results indicate that endothelial cells in culture constitutively release XO and that oxygenation rapidly enhances XO release. The released XO activity may play an important role in generation of oxidants in the extracellular milieu during reperfusion.     

Effect of morphine in vitro on the oxidative phosphorylation in rat liver mitochondria]

The rates of respiration in the presence of ADP and of phosphorylation as an ATP-ase activity of rat liver mitochondria was inhibited was in vitro by morphine with Ki=6.5 mM. The uncoupler-stimulated respiration of the mitochondria and the activity of ATP-ase and synthesis of ATP in the submitochondrial particles were not altered in the presence of morphine. It is suggested that morphine inhibited the adenine nucleotide transport through the mitochondrial membrane