Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.6.1.3 (ATPase)
 65,361 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Rats were exposed to a simulated altitude of 25,000 ft for 4 h in a decompression chamber, and the activity of some tissue enzymes estimated. Succinate dehydrogenase activity was significantly decreased and cholinesterase activity significantly elevated in the brain homogenates of the hypoxic rats, succinic dehydrogenase activity was significantly increased. There was no change in the activity of Mg+2-ATPase and Na+-K+-ATPase in the microsomal fractions of liver or brain homogenates of the hypoxic animals.
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PMID:Effect of acute hypoxia on the enzymes involved in the metabolic and nervous functioning of rat brain. 12 97

Cells of sarcoma 180 and of Ehrlich's carcinoma were maintained by serial transplantation in male and female Swiss mice. Either estrogen, progesterone, or testosterone were injected im at doses of 1 mg/mouse. Ascitic fluid was aspirated at intervals of 1, 3, 6, 24, and 48 hours following hormone injections. Enzyme activities were analyzed by subjective grading according to the intensity of staining reaction. Estrogen produced enhancement of alkaline phosphatase activity in both types of cells in both sexes of mice. Progesterone produced increased alkaline phosphatase activity in both types of cells from female hosts but an inhibitory effect in male hosts' cells. Testosterone produced no change in enzyme activity in tumor cells of female hosts but in male hosts it inhibited enzyme activity of sarcoma 180 cells and activated activity in carcinoma cells. The effect of all 3 hormones on acid phosphatase activity was activation. With adenosine triphosphatase, estrogen stimulated the activity in both types of tumor in both sexes. Progesterone stimulated cells from male hosts with little or no effect on cells from female hosts. This enzyme was resistant to testosterone. Succinate dehydrogenase activity under similar conditions was different. Estrogen reduced this activity and progesterone produced some inhibition of activity. Testosterone inhibited the sarcoma cells but had no effect on carcinoma cells of either sex. Others have shown that sex hormones affect the enzyme activities beyond the target tissues, particularly in the liver, kidney, and pancreas. Different responses of the enzymes seemed to depend on the endogenous hormonal status of the mice.
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PMID:Enzymatic responses of transplanted tumour cells towards estrogen, progesterone and testosterone. 13 8

Studies were carried out to determine the relationship between metabolic histopathological changes in the gastrocnemius muscle of rats in which an acute exudative inflammation had been induced by alkyldimethylbenzylammonium chloride (alkyl-DBAC, a cationic surfactant). Succinate respiration, Na+-K+-Mg2+ ATPase activity and ATP, ADP and AMP levels were determined as the index of metabolic changes. Myofascial edematous swelling with the acceleration of succinate oxidation and Na+-K+-Mg2+ ATPase activity was noted at 30 minutes in the inflamed muscle. The ATP level was also transiently reduced. On the other hand, Na+-K+-Mg2+ ATPase activity and succinate oxidation were inhibited by alkyl-DBAC, at this concentration, in vitro. These results support the possibility that enhancement of energy metabolism is not directly initiated by alkyl-DBAC but may be the result of certain chemical mediators released by alkyl-DBAC. The enhancement of energy metabolism continued after 1 hour and this energy may initiate leukocyte migration as well as increase vascular permeability and edema.
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PMID:Metabolic changes with inflammation induced by a surfactant. 14 13

Enzyme distribution profiles of clarified bovine mammary homogenates separated by equilibrium centrifugation on linear sucrose gradients suggested that several of the commonly utilized marker enzymes for rat liver are also valid markers for mammary cellular components. These marker enzymes include: Succinate dehydrogenase (mitochondria), nicotinamide adenine dinucleotide phosphate cytochrome c reductase and, to a lesser extent, retenone insensitive nicotinamide adenine dinucleotide cytochrome c reductase (endoplasmic reticulum), galactosyl transferase (Golgi apparatus), 5'-nucleotidase (plasma membranes), uric acid oxidase (microbodies), and acid phosphatase (lysosomes). Rotenone sensitive nicotinamide adenine dinucleotide cytochrome c reductase and sodium, potassium, magnesium-stimulated adenosine triphosphatase were widely distributed among subcellular fractions and are not valid marker enzymes. The boyant densities determined for the above fractions should aid in design of methods to obtain enriched sources of these components for analysis.
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PMID:Membranes of mammary gland. XI. Marker enzyme distribution profiles for membranous components from bovine mammary gland. 17 Dec 90

The histochemical localization of carbohydrates, ribonucleoproteins (RNA), lipids, some hydrolytic enzymes, succinate and lactate dehydrogenase and acetylcholinesterase were investigated in the prostate, urethral and bulbourethral glands of the camel. These glands probably secrete carbohydrate-protein complexes. In the bulbourethral glands, they are sulphated mucopolysaccharides. RNA was seen in the cytoplasm of the prostate and urethral glands. Neutral lipids were cytoplasmic and present in moderate amounts in the prostate and urethral glands and in traces, in the bulbourethral gland. Acid phosphatase-containing granules were abundant in the prostate, moderate in the urethral glands and in traces in the bulbourethral glands. Alkaline phosphatase was observed in the apical cytoplasm of the prostate and bulbourethral glands and in the ducts of the urethral glands. ATPase and adenosine 5-monophosphatase were seen in the basal laminae and interstitial tissue. In the urethral glands, adenosine 5-monophosphatase was distributed diffusely in the cytoplasm. Succinate dehydrogenase was seen in the urethral and bulbourethral glands. Varying degrees of lactate dehydrogenase activity was observed in all the glands. Acetylcholinesterase was confined to neural elements. The pars disseminata and the urethral glands were considered as two distinct glandular zones along the pelvic urethra. The significance of these histochemical results is discussed.
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PMID:Some histochemical studies on the prostate, urethral and bulbourethral glands of the one-humped camel (Camelus dromedarius). 18 43

1. The properties of membrane vesicles from the extreme thermophile Bacillus caldolyticus were investigated. 2. Vesicles prepared by exposure of spheroplasts to ultrasound contained cytochromes a, b and c, and at 50 degrees C they rapidly oxidized NADH and ascorbate in the presence of tetramethyl-p-phenylenediamine. Succinate and l-malate were oxidized more slowly, and dl-lactate, l-alanine and glycerol 1-phosphate were not oxidized. 3. In the absence of proton-conducting uncouplers the oxidation of NADH was accompanied by a net translocation of H(+) into the vesicles. Hydrolysis of ATP by a dicyclohexylcarbodi-imide-sensitive adenosine triphosphatase was accompanied by a similarly directed net translocation of H(+). 4. Uncouplers (carbonyl cyanide p-trifluoromethoxyphenylhydrazone or valinomycin plus NH(4) (+)) prevented net H(+) translocation but stimulated ATP hydrolysis, NADH oxidation and ascorbate oxidation. The last result suggested an energy-conserving site in the respiratory chain between cytochrome c and oxygen. 5. Under anaerobic conditions the reduction of cytochrome b by ascorbate (with tetramethyl-p-phenylenediamine) was stimulated by ATP hydrolysis, indicating an energy-conserving site between cytochrome b and cytochrome c. However, no reduction of NAD(+) supported by oxidation of succinate, malate or ascorbate occurred, neither did it with these substrates in the presence of ATP under anaerobic conditions, suggesting that there was no energy-conserving site between NADH and cytochrome b. 6. Succinate oxidation, in contrast with that of NADH and ascorbate, was strongly inhibited by uncouplers and stimulated by ATP hydrolysis. These effects were not observed when phenazine methosulphate, which transfers electrons from succinate dehydrogenase directly to oxygen, was present. It was concluded that in these vesicles the oxidation of succinate was energy-dependent and that the reoxidation of reduced succinate dehydrogenase was dependent on the outward movement of H(+) by the protonmotive force. 7. In support of the foregoing conclusion it was shown that the reduction of fumarate by NADH was an energy-conserving process. 8. If the activities of vesicles accurately represent those of the intact organism it appears that in B. caldolyticus the reduction of fumarate to succinate at the expense of reducing equivalents from NADH is energetically favoured over succinate oxidation even under aerobic conditions. This may be related to the need for an ample supply of succinate for haem synthesis in order to provide cytochromes for the organism.
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PMID:The oxidative activities of membrane vesicles from Bacillus caldolyticus. Energy-dependence of succinate oxidation. 20 11

1. The magnitude of the protonmotive force in phosphorylating membrane vesicles from Paracoccus denitrificans was estimated. The membrane potential component was determined from the uptake of S(14)CN(-), and the transmembrane pH gradient component from the uptake of [(14)C]methylamine. In each case a flow-dialysis technique was used to monitor uptake. 2. With NADH as substrate, the membrane potential was about 145mV and the pH gradient was below 0.5 pH unit. The membrane potential was decreased by approx. 15mV during ATP synthesis, and was abolished on addition of carbonyl cyanide p-trifluoromethoxyphenylhydrazone. In the presence of KCl plus valinomycin the membrane potential was replaced by a pH gradient of 1.5 units. 3. Succinate oxidation generated a membrane potential of approx. 125mV and the pH gradient was below 0.5 pH unit. Oxidation of ascorbate (in the presence of antimycin) with either 2,3,5,6-tetramethyl-p-phenylenediamine or NNN'N'-tetramethyl-p-phenylenediamine as electron mediator usually generated a membrane potential of approx. 90mV. On occasion, ascorbate oxidation did not generate a membrane potential, suggesting that the presence of a third energy-coupling site in P. denitrificans vesicles is variable. 4. With NADH or succinate as substrate, the phosphorylation potential (DeltaG(p)=DeltaG(0)'+RTln[ATP]/ [ADP][P(i)]) was approx. 53.6kJ/mol (12.8kcal/mol). Comparison of this value with the protonmotive force indicates that more than 3 protons need to be translocated via the adenosine triphosphatase of P. denitrificans for each molecule of ATP synthesized by a chemiosmotic mechanism. In the presence of 10mm-KNO(3) the protonmotive force was not detectable (<60mV) but DeltaG(p) was not altered. This result may indicate either that there is no relationship between the protonmotive force and DeltaG(p), or that for an unidentified reason the equilibration of SCN(-) or methylamine with the membrane potential and the pH gradient is prevented by NO(3) (-) in this system.
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PMID:The protonmotive force in phosphorylating membrane vesicles from Paracoccus denitrificans. Magnitude, sites of generation and comparison with the phosphorylation potential. 21 22

The effect of treating mitochondria with visible light above 400 nm on electron transport and coupled reactions was examined. The temporal sequence of changes was: stimulation of respiration coupled to ATP synthesis, a decline in ATP synthesis, inactivation of respiration, increased ATPase activity and, later, loss of the membrane potential. Loss of respiration was principally due to inactivation of dehydrogenases. Of the components of dehydrogenase systems, flavins and quinones were most susceptible to illumination, the iron-sulfur centers were remarkably resistant to being damaged. Succinate dehydrogenase was inactivated before choline and NADH dehydrogenase. Redox reactions of cytochromes and cytochrome c oxidase activity were unaffected. Inactivation was O2-dependent and prevented by anaerobiosis or the presence of substrates for the dehydrogenases. Light in the range 400-500 nm was most effective and the presence of free flavins greatly enhanced inactivation of all of the above mitochondrial activities. This suggests that visible light mediates a flavin-photosensitized reaction that initiates damage involving participation of an activated species of oxygen in the damage propagation.
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PMID:Damage to mitochondrial electron transport and energy coupling by visible light. 65 6

Stria vascularis from guinea pig cochleae was incubated in vitro to determine its metabolic response to variations in substrate and ion composition of the incubation medium. The respiratory rate at 37 degrees C in a medium containing glucose and pyruvate as substrate was 17.3 +/- 1.33 (SEM, n = 51) microliter O2/mg dry weight-hour. The stria could not maintain constant respiration by relying solely upon endogenous fuel stores. With substrate supplied, the ATP level could be maintained at about 73% of that existing in vivo. Glucose appears to be an adequate substrate for stria in vitro since glutamate, pyruvate, and fumarate did not increase the respiratory rate. Succinate increased respiration markedly but did not increase the ATP level. Ouabain (10(-4) M) caused a 48% decrease in the respiratory rate. Incubation in Na+-free and K"-free medium, each resulted in irreversible decrease of respiratory rate comparable to (or greater than) that caused by ouabain. These data are in accord with the high activity of Na+-K+-ATPase in the stria and the pronounced sensitivity of the endolymphatic potential to ouabain.
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PMID:Respiratory rate and ATP content of stria vascularis of guinea pig in vitro. 71 73

Limited data exist concerning the effects of exercise training on cellular oxidative capacity in the diaphragm of senescent animals. In this study we examined the changes in cellular oxidative capacity, muscle cell cross-sectional area (CSA), and capillarity within the costal diaphragm of senescent animals after a 10-wk endurance-training program. Twelve 24-mo-old female Fischer 344 rats were divided into either a sedentary control group (n = 6) or exercise training group (n = 6). The trained animals exercised on a motor-driven treadmill (60 min/day, 5 days/wk) at a work rate equal to approximately 55-65% VO2max. Capillaries were identified histologically and fiber types determined using adenosinetriphosphatase (ATPase) histochemistry. Succinate dehydrogenase (SDH) activity and CSA in individual fibers were measured using a computerized image analysis system. Exercise training did not increase (P > 0.05) the capillary-to-fiber ratio for any fiber type. However, training significantly decreased CSA (P < 0.05) and increased capillary density (capillary number/CSA) (P < 0.05) in type I, type IIa, and type IIb fibers. Furthermore, exercise training resulted in small but significant increase in SDH activity (P < 0.05) in type I and IIa fibers, whereas training did not alter SDH activity (P > 0.05) in type IIb fibers. These data demonstrate that endurance training in senescent animals results in small relative improvements in both oxidative capacity and capillary density in costal diaphragmatic type I and IIa muscle fibers. The increase in both capillary density and fiber SDH activity was largely due to a reduction in fiber CSA.
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PMID:Exercise-induced cellular alterations in the diaphragm. 144 27


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