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

The effects of fixation with various concentrations of glutaraldehyde or formaldehyde, acetone or ethanol, and freeze-drying on 5 phosphatases of Eimeria tenella and chick kidney cell cultures were demonstrated in situ. Gultaraldehyde inactivated the phosphatases more than did the formaldehyde, but the effect of the combination of the 2 (Karnovsky's fixative) was greater than that of either glutaraldehyde or formaldehyde alone. The higher the concentration of aldehyde and the longer the duration of exposure, the greater the inactivation. The order of sensitivity to aldehyde fixation of the enzymes tested was glucose-6-phosphatase greater than thiamine pyrophosphatase greater than 5'-nucleotidase greater than adenosine triphosphatase greater than acid phosphatase. Cytologic detail was preserved more efficiently with glutaraldehyde than with formaldehyde. Optimal preservation of enzyme activity for cytochemistry was with 2% glutaraldehyde for 30 min or 2% formaldehyde for 1 hr for G-6-Pase, TPPase, and 5'-nucleotidase, and with 2% glutaraldehyde or 2% formaldehyde for 2 hr with ATPase and AcPase. Quenching with subsequent fixation in cold acetone or ethanol resulted in complete inactivation of G-6-Pase, TPPase, and 5'-nucleotidase; although cells fixed in this manner yielded large amounts of reaction product for ATPase and AcPase, the distribution was diffuse, and some of it appeared to be artifactual. Quenching with subsequent freeze-drying was unsatisfactory because nearly all of the cell layers rolled off the cover glasses.
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PMID:Effect of fixation on demonstration of phosphatases of Eimeria tenella grown in chick kidney cell cultures. 6 Dec 71

Cyclic changes in the phosphatases were studied histochemically in the uterine complex of the female Suncus. Alkaline phosphatase activity showed constant and predictable changes in the various phases of the cycle with the maximum activity during metaestrus. Acid phosphatase and ATPase activities also showed constant changes with moderate activity during diestrus and proestrus but with maximal activities during estrus and metaestrus. No proper localization of the enzyme is discernible in the case of G-1-Pase and G-6-Pase.
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PMID:Cyclic changes in the uterine phosphatases of Suncus murinus sindensis Anderson, the Indian common house shrew. 16 62

A comparative study of glucose-6-phosphatase, alcaline RNase, ATPase, inosine diphosphatase and 5'-nucleotidase activities in isolated rat liver and hepatoma-27 nuclei and nuclear envelopes was performed. The tumor nuclear membranes were shown to be free from G-6-Pase activity in contrast to the liver nuclear membranes. The nuclear RNase activity was strongly inhibited in the hepatoma and could be unmasked in the presence of 3-10(-4) M pCMB. Hepatoma nuclear and nuclear envelopes ATP-ase activity was found to be moderately decreased as compared to those of the normal tissue. The values of inosine diphosphatase activity in hepatoma were similar to those in liver. The role of the nuclear envelope in nuclear-cytoplasmic interactions as well as nuclear location of G-6-Pase are discussed.
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PMID:[Various enzymes of isolated nuclear membranes and cell nuclei of the liver and hepatoma 27 of rats]. 19 29

(Diphenylphosphinodithioato) diphenylantimony (III), Ph2SbS2PPh2 (1) and (diisopropylphosphorodithioato) diphenylantimony(III), Ph2SbS2P(OPri)2 (2) were tested in vivo in male AKR mice and in vitro against Ehrlich ascites tumor cells. Both compounds exhibited dose-dependent inhibitory effects on in vivo tumor growth and on in vitro cell proliferation, cell viability, respiration and protein synthesis. The activities of some enzymes involved in energetic metabolism (Ca-ATPase, LDH, G6Pase) were exacerbated in vitro. The inhibitory effects could be related to the imbalance between ATP-producing and ATP-consuming processes in Ehrlich ascites tumor cells and also to their cell-cycle specificities.
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PMID:Antitumor organometallics. II. Inhibitory effects of two diphenyl-antimony (III) dithiophosphorus derivatives on in vitro and in vivo Ehrlich ascites tumor. 166 68

T3 administration to rats exerts quite different effects on enzyme activities associated to liver microsomal membranes such as G-6-Pase, Mg ATPase and Ca2(+)-dependent ATPase: in fact G-6-Pase activity is significantly enhanced, Mg ATPase is not affected whereas Ca2(+)-dependent ATPase is drastically inhibited. The T3 induced decrease in Ca2(+)-dependent ATPase activity is associated with a net reduction (to about 50% with respect to controls) of the Ca2+ sequestration in liver microsomal vesicles. The enhanced level of inorganic phosphate in the endoplasmic reticulum due to the stimulation of G-6-Pase activity does not significantly affect the uptake of calcium in microsomal vesicles. The decreased Ca2(+)-dependent ATPase activity is associated to an enhanced level of the enzyme in the phosphorylated form (E-P). This suggests that in liver preparations from T3 treated rats the turnover of ATP and cleavage of E-P is reduced, thus resulting in the accumulation of the phosphorylated intermediate. The accumulation of E-P is in agreement with the inhibition of the calcium sequestration since the active transport of this cation in microsomal membranes requires the hydrolysis of the E-P complex.
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PMID:Effect of triiodo-L-thyronine treatment on Ca2+ sequestration in rat liver microsomes. 217 82

The enzymic activities of hepatocytes, especially the bile canaliculi, of rats with experimental obstructive jaundice were studied by using electron microscopic cytochemistry. Common hepatic duct was ligated in rats, and liver tissue was taken from these animals 4 days after the operation for comparison with that of normal rats. The main results of this experiment were as follows: (1) Lumens of bile canaliculi were obviously enlarged. The microvilli became shortened and thickened, or even disappeared. The exoplasm was thickened as well. (2) The activity of Na(+)-K(+)-ATPase, G-6-Pase, Ca(++)-ATPase and NDPase in the wall of bile canaliculi was obviously reduced. (3) The activity of cytochrome oxidase in hepatocytes was also obviously reduced. The significance of the changes in these enzymic activity is discussed.
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PMID:[Cytochemistry of bile canaliculi in rats with experimental obstructive jaundice]. 217 87

In order to characterize the promoting activity of the peroxisome proliferator [4-chloro-6-(2,3-xylidino)-2-pyrimidinylthio]acetic acid (WY-14,463), male F344 rats which received a single 150-mg/kg dose of diethylnitrosamine (DEN) were fed 0.1% WY-14,643 or 0.05% phenobarbital in the diet for 11, 22, or 54 wk. WY-14,643 promoted the development of ATPase-deficient foci but not GGTase-positive or G6Pase-deficient foci, in contrast to phenobarbital which promoted development of foci detected by all three markers. The mode of promotion of ATPase-deficient foci by WY-14,643 was distinctly different from that of phenobarbital. WY-14,643 primarily increased mean volume of foci at 11 and 22 wk, while phenobarbital primarily increased the numerical density of foci at these time points. At 54 wk, the yield of hepatic neoplasms per liver was higher in rats fed WY-14,643 than in rats fed phenobarbital. To evaluate the possibility that the promotional activity of WY-14,643 was more effective at a later stage in hepatocarcinogenesis, rats receiving a dose of DEN and then phenobarbital in the diet for 11 wk were changed to a diet containing WY-14,643 for an additional 11 or 43 wk. However, WY-14,643 feeding from wk 11 to 22 caused a reduction in volume density of ATPase-deficient foci relative to the volume density of foci at 11 wk. In addition, feeding WY-14,643 from wk 11 to 54 caused similar yields of hepatic neoplasms whether or not phenobarbital was fed for the initial 11 wk. WY-14,643 induced hepatic peroxisome proliferation as indicated by palmitoyl CoA oxidase activity regardless of prior treatment with DEN and/or phenobarbital. The yield of neoplasms in rats not receiving DEN was greater in rats fed WY-14,643 for wk 11 to 54 than in rats fed WY-14,643 for wk 1 to 54. In summary, the peroxisome proliferator WY-14,643 was a more efficient promoter of hepatocarcinogenesis in DEN-initiated rats than phenobarbital. The promotional activity of WY-14,643, when evaluated by stereological analysis and by changing promoters, is distinct from that of phenobarbital, perhaps suggesting different cellular and/or molecular mechanisms of promotion. Understanding the role of promotion by WY-14,643 and other peroxisome proliferators may be important in understanding the mechanism of their hepatocarcinogenicity.
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PMID:Differences between the promoting activities of the peroxisome proliferator WY-14,643 and phenobarbital in rat liver. 256 80

Female F344/N rats were initiated with DEN (10 mg/kg) 24 h after a 70% partial hepatectomy. Groups of 10 rats were fed (a) AIN, group-1; (b) PD, group-2; or (c) NIH, group-3, for 1 week after initiation and were then fed NIH plus the promoting agent PB at a level of 0.05% in the diets for 6 months. Other groups were fed NIH for 1 week after initiation and then NIH without PB (group-4), AIN + PB (group-5), AIN without PB (group-6), PD + PB (group-7), or PD without PB (group-8) for 6 months. The numbers and volume percentages of AHF were quantified by stereologic methods from frozen serial sections, stained consecutively for GGT, ATPase, and G6Pase. For the groups fed different diets during the 1st week after initiation, the numbers and volume of AHF were significantly greater in group-2 than in groups 1 or 3. The numbers of AHF were significantly less in group-3 than in group-1. The numbers and volume of AHF were significantly greater in groups fed PB during the promotion phase, except in the case of group-7, whose focal volume did not differ from groups 6 or 8. Group-3 had significantly greater numbers of AHF than groups 5 and 7. These findings can be explained by the hypothesis that the NIH diet contained factors that acted synergistically with PB to enhance tumor promotion. The mean focal volume of both GGT positive and ATPase negative foci was significantly greater in group-5 than in all other groups; this indicates that the AIN + PB regimen selectively promoted the growth of a subpopulation of AHF. These findings show that alterations in the composition of diets fed during hepatocarcinogenesis significantly alter the effects of specific chemical agents acting during the stages of initiation and promotion in hepatocarcinogenesis.
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PMID:Dietary effects on initiation and promotion of hepatocarcinogenesis in rat. 289 12

Membrane bound phosphohydrolysing enzymes, such as Na-K-ATPase, Mg-ATPase, ALPase and G-6-Pase were assayed in intact liver, in freshly isolated cells and in cultured hepatocytes to evaluate the effects of the isolation procedure and culture on these enzyme activities. Na-K-ATPase and Mg-ATPase are significantly reduced following cell dispersion while ALPase and G-6-Pase are nearly unaffected. During culture, Na-K-ATPase is restored to the "in vivo" level within the first two days, but rapidly declines in the following days. The Na dependent, energy requiring AIB uptake shows a similar pattern; Mg-ATPase is practically unmodified. A significant increase in ALPase activity and a net decrease of G-6-Pase activity, as a function of the culture time has been observed.
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PMID:Membrane phosphatase activities in isolated and cultured adult rat hepatocytes. 299 17

The clonality of chemically induced altered hepatocellular foci was examined in rat liver. Chimeric rats composed of two histologically distinguishable cell lineages were placed on an initiation-promotion protocol for liver cancer induction. This resulted in multiple lesions of altered enzyme expression. These altered hepatocellular foci are generally considered to be initiated sites susceptible to cancer formation. The cellular origins of these lesions were determined by aligning sections demonstrating cell lineage with serial sections stained for altered enzyme expression. Analysis included 110 areas of deficient ATPase (EC 3.6.1.3) activity and 59 glucose-6-phosphatase (EC 3.1.3.9; G-6-Pase) deficient lesions, 744 foci of re-expression of gamma-glutamyl transpeptidase (EC 2.3.2.2; gamma-GT), and decreased glycogen mobilization (187 lesions). Of the 1100 focal enzyme alterations, 1054 were shown to be composed entirely of cells from a single lineage of the two lineages present in the mosaic tissue. Multiple alterations occurred within given lesions. Lesions with up to four phenotypic alterations were found to consist of cells of a single lineage. These results suggest that individual enzyme-altered foci are clonal in origin and that phenotypic heterogeneity within altered hepatocellular foci is due to lesion progression within a clonal population and not to a multicellular derivation.
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PMID:Clonality of preneoplastic liver lesions: histological analysis in chimeric rats. 319 1


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