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Query: UNIPROT:P20020 (adenosine triphosphatase)
 3,299 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The adenosine triphosphatase (ATPase) activities of human polymorphonuclear leukocytes (PMNL) were studied with an assay that monitored the release of 32P-labeled inorganic pyrophosphate (32P1) from gamma-[32P]adenosine 5'-triphosphate (ATP). In cell homogenates, (Na+ + K+)-sensitive, ouabain-inhibitable ATPase comprised an insignificant fraction of the total ATPase activity. Additions of p-nitrophenyl phosphate and beta-glycerophosphate (substrates for nonspecific acid and alkaline phosphatases) and of tartrate (inhibitor of acid phosphatase) gave no indication of inhibition. This suggested that the assay was relatively specific for ATP hydrolysis. The activity was found to have a pH optimum of 8.7 and a Km for ATP of 0.6 mM. There was an absolute requirement for Mg2+, with other divalent cations substituting less efficiently. When the Mg2+-dependent ATPase activity of intact cells was compared with that in homogenized cells, no significant difference was observed. The activity in intact cells was linear with respect to incubation time up to at least l0 min. Trypan blue staining and lactate dehydrogenase assays revealed that greater than 92% of the PMNL remained intact and viable during the assay. No soluble ATPase was released from the cells under assay conditions. In following the distribution of gamma[32P]ATP and 32P2 counts became cell associated. Since the experimental evidence supports the observation that PMNL remain intact and viable and that ATP does not penetrate the cell under assay conditions, it is proposed that greater than 90% of the Mg2+-dependent ATPase of the human PMNL is associated with a plasma membrnae enzyme. This would qualify the enzyme for the role of a plasma membrane marker for future fractionation and isolation attempts.
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PMID:Magnesium-dependent adenosine triphosphatase as a marker enzyme for the plasma membrane of human polymorphonuclear leukocytes. 1 92

In the gastrocnemius muscle of cat and rat, staining for oxidative enzymes differentiated three fiber types (A,B,C) and staining for adenosine triphosphate at pH 9.4 differentiated two fiber types (I, II) with a reliability of 90% and 98%, respectively. In cat 96% and in rat 90% of the fibers were typed identically after staining for nicotinamide adenine dinucleotidelinked lactic dehydrogenase (LDH) and succinic dehydrogenase (SDH). When differentiated by staining for LDH, A and B fibers were of type I. IN RAT, 80-90% OF ALL FIBERS WERE OF TYPE 22, COMPPRISING A, B and C fibers. Type I fibers stained for LDH intensely as did C fibers of type II, but stained intermediately for SDH. The degree of staining was measured by photometry. When fibers were stained for LDH, histograms of density showed three peaks corresponding to A, B and C fibers in cat, but only two peaks corresponding to A and C fibers in rat, In cat and rat, the densities of A, B and C fibers belonged to different populations. In soleus muscle of cat and rat stained for LDH, menadione-linked alpha-glycerophosphate dehydrogenase and adenosine triphosphatase at pH 9.4, the degree of staining differed from thatin any type of fiber in gastrocnemius muscle
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PMID:Histochemical fiber typing and staining intensity in cat and rat muscles. 12 97

Muscle samples were obtained from the gastrocnemius of 17 female and 23 male track athletes, 10 untrained women, and 11 untrained men. Portions of the specimen were analyzed for total phosphorylase, lactic dehydrogenase (LDH), and succinate dehydrogenase (SDH) activities. Sections of the muscle were stained for myosin adenosine triphosphatase, NADH2 tetrazolium reductase, and alpha-glycerophosphate dehydrogenase. Maximal oxygen uptake (VO2max) was measured on a treadmill for 23 of the volunteers (6 female athletes, 11 male athletes, 10 untrained women, and 6 untrained men). These measurements confirm earlier reports which suggest that the athlete's preference for strength, speed, and/or endurance events is in part a matter of genetic endowment. Aside from differences in fiber composition and enzymes among middle-distance runners, the only distinction between the sexes was the larger fiber areas of the male athletes. SDH activity was found to correlate 0.79 with VO2max, while muscle LDH appeared to be a function of muscle fiber composition. While sprint- and endurance-trained athletes are characterized by distinct fiber compositions and enzyme activities, participants in strength events (e.g., shot-put) have relatively low muscle enzyme activities and a variety of fiber compositions.
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PMID:Skeletal muscle enzymes and fiber composition in male and female track athletes. 12 49

Skeletal muscles of flight rats showed no changes in the content of glycogen, adenosine triphosphatase activity of myosin and protein content in protein fractions (except the T fraction where the protein content increased on the 1st and returned to the normal on the 26th postflight day). On the 1st postflight day activities of aminotransferases and lactate dehydrogenase of sarcoplasmatic proteins were elevated and the isoenzyme spectrum of LDH was changed as if in muscular atrophy. The amount of free amino acids in muscles was lowered. On the 26 the postflight day the enzymic activity of sarcoplasmatic proteins remained increased whereas the isoenzyme spectrum of LDH returned to the normal and the amount of free amino acids grew significantly. In the microsomal fraction of muscles the phospholipid content decreased on the 1st and returned to the normal on the 26th postflight day.
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PMID:[Effect of a 22-day space flight on the metabolism of rat skeletal muscle tissue]. 13 80

A cell line (HGC-27) was established by culture of the metastatic lymph node from a gastric cancer patient diagnosed histologically as undifferentiated carcinoma. HGC-27 cells were polygonal or short spindle-shaped and adhered to glass surfaces as a monolayer. The cells were probably derived from gastric cancer cells, as their origin from mesenchymal tissues can be excluded morphologically and enzyme-histochemically. Enzyme activities were generally negative or low, except for adenosine triphosphatase, lactic dehydrogenase and leucine aminopeptidase. These scanty findings might reflect the undifferentiated character of the original tumor cells. The cloning efficiency was 5.3% in liquid medium and 1.0% in soft agar. The doubling time was about 17 hr. Chromosomal analysis revealed a mode of 109 and 110 chromosomes.
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PMID:Human cell line (HGC-27) derived from the metastatic lymph node of gastric cancer. 13 73

The effect of depersolone, of the oxygenation of the perfusing solution and of phenoxybenzamine pretreatment has been studied in the isolated rat liver intermittently perfused with a solution containing low molecular weight dextran at 4 degrees C. The use in liver preservation of Collins' C3-solution and of a special albumin-containing solution was tested. The behaviour of acid and alkaline phosphatase, esterase, lactate dehydrogenase and adenosine triphosphatase in the preserved liver was followed by means of histochemical methods allowing semi-quantitative evaluation. Pretreatment with phenoxybenzamine and perfusion by an albumin-containing solution reduced the lesion of the liver, while prednisolone and oxygenation of the perfusion solution improved preserving effect only moderately.
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PMID:Enzyme histochemical studies of the preserved rat liver. 14 May 69

1. Homogenates of guinea-pig left ventricle were fractionated by differential pelleting and by centrifugation on continuous sucrose density gradients. 2. The principal subcellular organelles of myocardium, characterized by their marker enzyme content, were resolved by density gradient centrifugation in a small-volume zonal rotor. The equilibrium densities (p) of the principal organelles are (with marker enzymes in parentheses): sarcolemma, 1-12 (5'-nucleotidase); lysosomes, 1-16 (N-acetyl-beta-glucosaminidase); mitochondria, 1-17 (cytochrome oxidase); peroxisomes, 1-18 (catalase); cytosol (lactate dehydrogenase). 3. The subcellular distribution of various adenosine triphosphatase activities and previously unassigned enzymes was determined. Leucyl-beta-naphthylamidase and gamma-glutamyl transpeptidase showed both cytosol and sarcolemma components. Ca2+-dependent adenosine triphosphatase showed dual localization to the mitochondria and to the sarcolemma.
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PMID:Analytical subcellular fractionation of guinea-pig myocardium. 14 54

Male guinea pigs were exposed to nitrogen dioxide (2 mg/m3) during 180 days (8 hours a day). Long-term exposure induced thickening of the corneal layer of the epidermis as well as inflammatory infiltrations in the proper skin. The following enzymes were estimated histochemically in skin samples of experimental and control animals: succinic dehydrogenase, NADH2-tetrazolium reductase, lactate dehydrogenase; alkaline phosphatase, acid phosphatase and adenosine triphosphatase. Chronic exposrue stimulated a decrease of NADH2-tetrazolium reductase in the epidermis and connective tissue components of proper skin and marked positive reaction of lactate dehydrogenase in epidermal cells and hair follicles. Increase of a diffuse reaction on adenosine triphosphatase in smooth muscles of the skin was found also in exposed animals.
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PMID:Histopathological and histochemical studies of the skin of guinea pigs after long-term exposure to nitrogen dioxide. 14 74

EEG registered hippocampal status epilepticus (HSE) was provoked in 41 adult albino rats by intraseptal injection of ouabain, and the hippocampus was studied from 1 1/2 to 24 hr with the enzyme histochemical tests for succinic dehydrogenase (SDH), lactic dehydrogenase (LDH), thiaminopyrophosphatase (TPPase), acid phosphatase (AcPase), Mg2+ adenosine triphosphatase (Mg2++ ATPase), and with general and neurohistological stains. In a first group of animals (1 1/2 to 10 hr of HSE), a stage of general increase in enzymatic activity was detected in the pyramidal neurons (SDH, LDH, AcPase, and TPPase). Mg2+ ATPase showed a marked increase in astrocytes. In a second group (more than 10 hr of HSE), SDH was found decreased in the dendritic fields. LDH activity persisted in neuronal bodies, and AcPase and TPPase showed diffuse activity in the cytoplasm of some pyramidal neurons. In a third group (more than 18 hr of HSE), SDH activity was low. No AcPase granules were observed in some pyramidal neurons and TPPase was negative in some areas of pyramidal layer. Mg2+ ATPase reaction showed scare and retracted astroglial processes. These changes were coincident with "cellular ghosts" observed with hematoxylin-eosin techniques of the same samples in the pyramidal field and were interpreted as cellular death, attributed to relative anoxia following neuronal discharge.
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PMID:Enzyme histochemistry of the rat hippocampus during experimental status epilepticus. 15 26

1. Incubation of human and rat hepatoma cells with insulin (1 mU/10(6) cells) decreases their content of adenosine 3':5'-monophosphate by more than half after 1 h and by about a quarter after 4 h. 2. The activities of the ATP-metabolising enzymes, adenylate kinase and Mg2+-adenosine triphosphatase are significantly increased by insulin within 1 h and after 4 h. Activity of succinate dehydrogenase and lactic dehydrogenase showed no change at either time interval. 3. Insulin markedly stimulated glucose 6-phosphate dehydrogenase activity within 1 h but by 4 h the increase was less apparent. Glutamate dehydrogenase activity by contrast was not increased by 1 h but was elevated at 4 h.
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PMID:The influence of insulin on various enzyme activities in human and rat hepatoma cells. 17 8


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