Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P20020 (adenosine triphosphatase)
 3,299 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Male Wistar rats were given 50 mug of aflatoxin B1 twice a week for 4 weeks, and thereafter 75 mug twice a week for 10 weeks. Their livers were investigated histologically and histochemically for glycogen, RNA, fat, alkaline and acid phosphatases, adenosine triphosphatase, 5'-nucleotidase, glucose-6-phosphatase, glucose-6-phosphate dehydrogenase, succinic dehydrogenase, and alkaline and acid nucleases. No significant lesions occurred before 15 weeks. During this period, the liver was histochemically unchanged except for a periportal decrease of alkaline phosphatase and adenosine triphosphatase. Scattered hepatocytes with a strong glucose-6-phosphatase activity appeared. These changes represent toxic effects of aflatoxin B1 and are irrelevant to carcinogenesis. From 15 weeks onward, three types of liver cell hyperplastic foci and nodules developed. Histologically, and with respect to glycogen, fat, and RNA content, only two of these types were considered as potential precursors of hepatocarcinomas. However, all types exhibited a decrease or absence of the enzymes studied. Both histological and histochemical changes stressed the complex heterogeneity existing between and within hepatic foci and nodules. From 11 months on, hepatocarcinomas developed. The tumors disclosed similar histochemical changes. This similarity further supports the "precarcinomatous" nature of hyperplastic foci and nodules. It appears that focal changes in surface as well as in cytoplasmic and nuclear enzymes are intimately and very early linked to the carcinogenic process. Whether they are fundamental or only represent an epiphenomenon remains unclear.
 ...
PMID:Sequential histological and histochemical study of the rat liver during aflatoxin B1-induced carcinogenesis. 16 70

The hydrolysis of disodium p-nitrophenyl phosphate at pH 9.0 by slices of formaldehydee-fixed rat renal cortex was investigated by colorimetric estimation of the nitrophenol liberated. It was found that three types of activity could be identified on the basis of their responses to inhibitors and cations: (a) alkaline phosphatase sensitive to inhibition by L-tetramisole; (b) potassium-dependent phosphatase, probably identifiable with the phosphatase component of sodium-potassium-dependent transport adenosine triphosphatase (?Na-K-ATPase); and (c) alkaline phosphatase insensitive to L-tetramisole. It was found that in the presence of strontium ions, as used in Na-K-ATPase cytochemistry, the activities of the second and third types of enzyme were approximately equal. The implications of these findings for the cytochemical demonstration of Na-K-ATPase are discussed.
 ...
PMID:The significance of inhibitor-resistant alkaline phosphatase in the cytochemical demonstration of transport adenosine triphosphatase. 16 3

Plasma membranes were isolated from the yeast and mycelial forms of Candida albicans as described previously (Marriott, 1975) and examined for the presence of several enzymes. Measurement of specific activities showed enrichment of Mg2+-dependent and Ma+/K+-stimulated Mg2+-dependent adenosine triphosphatase and mannan synthetase, in the plasma membrane fractions from both morphological forms of the organism. However, acid and alkaline phosphatase, NADH oxidase and 5'-nucleotidase showed no such specific location.
 ...
PMID:Enzymic activity of purified plasma membranes from the yeast and mycelial forms of Candida albicans. 17 Mar 63

5' -Nucleotidase activity was determined in rat thyroid and some other organs employing a specific assay method. During the course of methylthiouracil (MTU) treatment, thyroid 5'-nucleotidase activity decreased significantly. This decrease was specific for this enzyme since the activity of neutral phosphatase did not change and the activity of alkaline phosphatase and Mg2+-activated adenosine triphosphatase increased markedly. The 5'-nucleotidase activity of the adenohypophysis also decreased following MTU treatment. This enzyme activity of the liver, heart and whole brain remained unchanged after the treatment. The role of this enzyme was discussed in relation to tissue growth and increased contents of RNA and DNA in the thyroid and adenohypophysis.
 ...
PMID:Reduction of 5'-nucleotidase activity in rat thyroid and adenohypophysis following methylthiouracil treatment. 17 98

Potassium-stimulated p-nitrophenylphosphatase (K+-pNPPase) activity was investigated in rat somatosensory cortex where 64-88% of enzymatic activity survived 5-10 min of fixation with 3% formaldehyde in 0.1 M cacodylate buffer, pH 7.4. Potassium-stimulated activity was inhibited by 1-10 mM ouabain. Levamisole (1.7 mM) inhibited brain alkaline phosphatase activity, facilitating the detection of K+-pNPPase activity. Strontium (10-20 mM) inhibited enzymatic activity by 38-75%. In parallel histochemical studies reaction product was found in strata, with cortical layers 2, 3, 4 and the outer portion of 5 containing the heaviest deposits. Highly reactive, vertically oriented, large diameter fibers were seen as groups between the outer portion of layer 5 and the pail surface. These fibers apparently arborize in the superficial layers. Smaller fibers were also positive and were oriented in various planes. The highest density of smaller, positive fibers occurred in layers 2 through 5. All positive fibers appeared to be axons or dendrites. Reaction product was not heavily concentrated in neuron perikarya or in glial elements. Sections did not contain reaction product when incubated in media lacking K+ or containing ouabain. The convergence of data from parallel histochemical and biochemical approaches supports the conclusion that the reactivity localized in the cerebral cortex represented the site of K+-pNPPase, a known component of the Na+,K+-adenosine triphosphatase complex. Neuronal processes demonstrated the highest enzymatic activity and may be most important in the active transport of Na+ and K+ in somatosensory cortex.
 ...
PMID:Histochemical localization of potassium-stimulated P-nitrophenylphosphatase activity in the somatosensory cortex of the rat. 18 89

The activity of succinic dehydrogenase, adenosine triphosphatase, alkaline phosphatase and cytochrome oxidase was studied histochemically in the remaining kidney of male albino rats which had been subjected to unilateral nephrectomy and were subsequently treated with aldosterone. A marked increase in the activity of succinic dehydrogenase, adenosine triphosphatase and alkaline phosphatase was noted on the initial postoperative days. The increase noted in succinic dehydrogenase activity is considered particularly important because in the control group succinic dehydrogenase activity remained unchanged throughout the experiment.
 ...
PMID:Histochemical changes effected by aldosterone on compensatory renal growth in the rat. 18 76

Ectodermal cells of the two- and three-germ layer-thick mouse egg-cylinders are considered to be the progenitors of embryonal carcinoma cells in embryo-derived teratocarcinomas. In an attempt to find differences between the tumor cells and equivalent embryonic cells, we have studied the electron microscopic cytochemical localization of alkaline phosphatase, 5'-nucleotidase, and Mg2+-activated adenosine triphosphatase (ATPase) in embryo-derived teratocarcinomas and mouse egg-cylinders. Alkaline phosphatase was detected in both embryonic and tumor cells, but its activity appeared much more intense in the tumor cells. No ATPase was demonstrated in embryonic ectodermal cells of 6-day-old embryos and only in occasional cells of 7- and 8-day-old embryos. No 5'-nucleotidase activity could be demonstrated in 6- to 8-day-old cylinders. There was marked ATPase and 5'-nucleotidase activity in the membranes of embryonal carcinoma cells. These data point out some differences on the plasma membrane between the embryonal carcinoma cells and equivalent embryonic cells. The potential significance of these differences is discussed with regards to the transformation of embryonic cells in tumor cells. (Am J Pathol 87:297-310, 1977).
 ...
PMID:Ultrastructural localization of membrane phosphatases in teratocarcinoma and early embryos. 19 83

Rats were made to drink D2O mixed water (30: 70) for 6 weeks in order to study the biological effects of orally administered D2O on the liver. Heavy water administration results in gradual decrease in the body weight whereas the liver showed marginal increase in weight throughout the experimental period. Phosphatases and dehydrogenases were analyzed biochemically. Acid phosphatase, glucose-6-phosphatase and adenosine triphosphatase registered fall in contrast to alkaline phosphatase, SDH and LDH, all of which showed a definite increase. Lipids, nucleic acids and proteins, estimated biochemically, gradually decreased throughout the experimental period in response to D2O feeding.
 ...
PMID:Biologic effects of orally administered deuterium oxide on rat liver. 19 33

The distribution of enzymes, viz., alkaline phosphatase, acid phosphatase, adenosine monophosphatase and adenosine triphosphatase was studied by histochemical methods in the accessory respiratory organs of two fresh-water fishes (Clarius batrachus and Heteropneustes fossilis). Enzymes have been used as markers to differentiate between functional and non-functional cells of the dendritic organ of Clarius and of the air chamber of Heteropneustes. The variations in the enzyme activities have been correlated with the functional capacity of each respiratory organ. It is attempted to understand the physiological role of these enzymes in the process of aerial breathing.
 ...
PMID:Phosphatases in the accessory respiratory organs of two fresh-water fishes. 20 22

Human parotid glands, submandibular glands, and pleomorphic adenomas were examined by electron microscopic histochemistry. All epithelial cells of the normal salivary glands showed plasma membrane adenosine triphosphatase (ATPase) and inosine diphosphatase (IDPase) activity. However, myoepithelial cells reacted most intensely. Pleomorphic adenomas showed epithelial cells within solid and ductal portions of the tumors that were variably reactive for both ATPase and IDPase. Histochemical examination of the epithelial cells in the myxoid portions of the tumors did not provide conclusive evidence as to the nature of their progenitor cells. Surface-associated phosphatases (alkaline phosphatase, ATPase, and IDPase) cannot be reliably used as histochemical markers of salivary gland myoepithelial cells. Therefore, morphological and phosphatase histochemical studies that intend to examine the role of myoepithelial cells in salivary gland neoplasms must be interpreted with care.
 ...
PMID:Phosphatase enzymes. Cytochemical study of pleomorphic adenoma and normal human salivary glands. 20 48


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>