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)

Electron microscopic cytochemistry was used to determine the localization of five phosphatase enzymes-glucose-6-phosphatase, inosine diphosphatase, thiamine pyrophosphatase, acid phosphatase, and adenosine triphosphatase-in control human testes. Glucose-6-phosphatase occurred in the endoplasmic reticulum and nuclear envelope of Sertoli cells, Leydig cells and primitive spermatogonia, but was not observed in more advanced spermatogenic cells. The presence of glucose-6-phosphatase activity paralleled the presence of glycogen in spermatogenic cells, i.e., both occurred in type AL and AD spermatogonia but not in type AP or B spermatogonia or in more advanced spermatogenic cells. Inosine diphosphatase activity was found in the endoplasmic reticulum, nuclear envelope, and Golgi complex of Sertoli cells and all spermatogenic cells except late spermatids. Additionally, inosine diphosphatase activity was localized at the junctions between Sertoli cells and late spermatids, but was not associated with any other plasma membrane. Thiamine pyrophosphatase reaction product was found in the Golgi bodies of Sertoli cells and in spermatogenic cells through immature spermatids. Neither inosine diphosphatase nor thiamine pyrophosphatase was observed in the Golgi bodies of spermatids during acrosomal formation. Acid phosphatase activity was found in lysosomes of spermatogonia, spermatocytes, and spermatids, in lysosomes of Leydig cells, and in lysosomes, lipofuscin bodies, and Golgi cisternae of Sertoli cells. It is thought that Sertoli lysosomes play a role in the phagocytosis of degenerating germ cells; however, the role of spermatogenic or Leydig lysosomes is unknown. Adenosine triphosphatase activity occurred at the interfaces between two spermatogonia, and between Sertoli cells and spermatogonia, but was not observed in the spaces between two Sertoli cells, two spermatocytes, two spermatids, or between Sertoli cells and spermatocytes, or between Sertoli cells and spermatids.
 ...
PMID:The fine structural localization of testicular phosphatases in man: the control testis. 17 58

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

The endothelium releases factor(s) that are potent vasodilators and inhibitors of platelet aggregation. Experiments were performed to determine whether the endothelium-dependent responses to aggregating platelets are altered in vein grafts. Segments of jugular veins were grafted in the reverse position into the carotid arteries in 16 rabbits. After 4 weeks the patent grafts (14 of 16) were removed, and the endothelium-dependent responses were examined in vitro. In control veins aggregating platelets, adenosine diphosphate, and serotonin caused endothelium-dependent relaxations. The platelet-induced relaxations were attenuated by apyrase (adenosine diphosphatase and adenosine triphosphatase) but not by methiothepin (serotonergic blocker). In vein grafts, endothelium-dependent relaxations in response to aggregating platelets were absent, and only contractions that could be attenuated by methiothepin were observed. In vein grafts, endothelium-dependent relaxations in response to adenosine diphosphate were reduced, and only endothelium-independent contractions were observed in response to serotonin. These contractions were attenuated by methiothepin. These results suggest that (1) the endothelium exerts an inhibitory effects mediated mainly by adenosine diphosphate in response to aggregating platelets in rabbit jugular veins and (2) endothelium-dependent relaxations in response to aggregating platelets are impaired in vein grafts because of reduced endothelium-independent contractions in response to serotonin. This impairment of endothelium-dependent responses in vein grafts may contribute to failure of the grafts.
 ...
PMID:Endothelium-dependent vasorelaxations in response to aggregating platelets are impaired in reversed vein grafts. 211 36

1. The origin of the limiting membranes of autophagic vacuoles (AVs) in mouse pancreatic acinar cells was studied in vinblastine-induced autophagocytosis. 2. The marker enzymes used were adenosine triphosphatase, lipase, inosine diphosphatase and thiamine pyrophosphatase. The following impregnation techniques were used: unbuffered osmium tetroxide impregnation, imidazole-buffered osmium tetroxide impregnation and uranyl-lead-copper impregnation. 3. Only a weak lipase activity was observed between the limiting membranes of a few AVs. The AV membranes were stained heavily with all impregnation techniques used. 4. The origin of AV membranes seems to be same in mouse liver and exocrine pancreas in vinblastine-induced autophagocytosis.
 ...
PMID:Cytochemical studies on induced autophagocytosis in mouse exocrine pancreas. 245 89

Perirenal adipose tissue samples were obtained from fetuses removed from pregnant (crossbred) sows at 3 stages of gestation (70, 90 and 110 days). Phosphatase histochemistry, succinate dehydrogenase (SDH) histochemistry and factor VIII antigen immunocytochemistry were conducted on fresh-frozen cryostat sections. Age-associated changes in nucleosidediphosphatase (NDPase) reactions in the arteriolar system were correlated with the morphological development of the medial layer of arterioles and arteries. For instance, a strong NDPase reaction in small arterioles was associated temporally with the assumption of a normal smooth-muscle cell morphology and arrangement in the medial layer. Age-associated changes in blood vessel reactions for factor VIII antigen and alkaline phosphatase activity were not correlated with morphological development. In the youngest fetuses, alkaline phosphatase activity was evident in large and small arterioles, but in the oldest fetuses, alkaline phosphatase activity was restricted to the smallest arterioles and vessels associated with them. Arteriolar differentiation was demonstrable with either adenosine triphosphatase (ATPase) or inosine diphosphatase (IDPase) reactions. Primordial stromal cells around differentiated arterioles were reactive for ATPase but not for IDPase activities. In older fetuses, there were large areas that contained ATPase-reactive stromal cells, no adipocytes, differentiated (ATPase and IDPase) arterioles and few capillaries. Positive reactions for SDH were evident in the ATPase-reactive stromal areas that contained no adipocytes. Differentiated adipocytes were SDH- and ATPase-reactive. These data illustrate the utility of differential phosphatase histochemistry to identify adipose tissue primordia.
 ...
PMID:Identification of adipose tissue primordia in perirenal tissues of pig fetuses: utility of phosphatase histochemistry. 303 70

Bound, soluble, and whole-cell fractions of two strains of the gliding bacterium Vitreoscilla were found to contain two enzymes capable of hydrolyzing adenosine phosphates: a Mg(++)-activated adenosine triphosphatase with a temperature optimum of 37 C, and a Mg(++)-activated adenosine diphosphatase with a temperature optimum of 55 C. Both enzymes had an optimal pH response between 8.5 and 9.5. Maximal activation was achieved at an ionic strength of 0.2 for the adenosine triphosphatase and at 0.3 to 0.4 for the adenosine diphosphatase. Preliminary studies indicated a molecular weight of approximately 50,000 for the adenosine diphosphatase and a molecular weight greater than 60,000 for the adenosine triphosphatase. Comparisons are made with previously reported characteristics of these enzymes in other bacteria, and a hypothesis is offered as to the role these enzymes have in the gliding mechanism.
 ...
PMID:Adenosine phosphate hydrolases in cell fractions of Vitreoscilla. 428 6

Treatment of an isoenzyme of potato apyrase of high adenosine triphosphatase/adenosine diphosphatase (ATPase/ADPase) ratio with iodine, N-acetylimidazole or tetranitromethane inactivates the ATPase activity of this enzyme faster than its ADPase activity. There was protection by substrates with the two last-named substances. This and the appearance of nitrotyrosine suggests the participation of tyrosyl residues in both enzymic activities of potato apyrase. The participation of thiol groups is excluded by the insensitivity of apyrase to p-chloromercuribenzoate. Also, 2-hydroxy-5-nitrobenzyl bromide or carboxymethylation produce the same rate of inactivation of ATPase and ADPase activities. Substrates protect both activities from inactivation. Hydrogen peroxide and photo-oxidation inactivate ATPase activity faster than ADPase activity. There is no protection by substrates. Analysis of pH effects on V(max.) and K(m) suggest different pK values for the amino acid residues at the ATP and ADP sites.
 ...
PMID:Effects of protein-modifying reagents on an isoenzyme of potato apyrase. 435 57

Ultrastructural localizations of phosphatases were observed in the rat parathyroid gland. Activities of alkaline phosphatase and adenosine triphosphatase were found on the caveolae or pinocytotic vesicles of the capillary endothelia. In the parenchymal cells, they were demonstrated to be stronger both at the plasma membranes facing the pericapillary space and at their transitional portions to the lateral plasma membranes than at the remaining lateral plasma membranes including microvilli. Activities of thiamine pyrophosphatase and inosine diphosphatase were detected on one or two layers of lamellae at the inner face of the Golgi apparatus, and the localization of the latter enzyme was more restricted than that of the former. Additionally, they were sometimes observed also on the blood capillary wall. Contrasted to these enzymes, acid phosphatase activity was demonstrated on the entire Golgi lamellae besides lysosomes, but not on multivesicular bodies, vacuolar bodies and storage granules.
 ...
PMID:Ultrastructural localization of phosphatases in the rat parathyroid gland. 610 56

Ultracytochemical study was made of inosine diphosphatase (IDPase) and adenosine triphosphatase (ATPase) in the nuclei of normal epithelial and cancer cells of human gastric tumors. A new incubation medium for ultracytochemical demonstration of IDPase activity in the cell nuclei was developed. The activity of IDPase and ATPase in the nucleoplasm and in the nucleoli of the tumor cells was shown to be lower than in respective normal cells. IDPase activity in the nuclear envelope in the tumor cells was absent in contrast to the normal cells.
 ...
PMID:[Ultracytochemical study of the nucleoside phosphatase activity of nuclei of epithelial cells of the gastric mucosa and of stomach cancer cells in humans]. 610 95

Specific assays for 5'-nucleotidase, adenosine diphosphatase (ADPase) and Mg2+-dependent adenosine triphosphatase (Mg2+-ATPase) have been optimized for human lymphocytes and their subcellular localizations determined by sucrose density gradient centrifugation. 5'-Nucleotidase was localized solely to the plasma membrane of the lymphocyte. ADPase activity has been shown to have a dual localization to the plasma membrane and mitochondria, whilst Mg2+-ATPase was mainly located in the mitochondria. No [Na+,K+] activated Mg2+-dependent ATPase could be measured in these cells. We have confirmed the striking decrease in the specific activity of 5'-nucleotidase activity in lymphocytes from patients with common variable primary hypogammaglobulinaemia. In contrast, the specific activities of ADPase and Mg2+-ATPase showed no alteration in lymphocytes from the patient group when compared to controls. Thus the deficiency of ecto-5'-nucleotidase in the lymphocytes of patients with hypogammaglobulinaemia is a highly selective defect in purine metabolism.
 ...
PMID:Studies on the kinetic properties and subcellular localization of adenine nucleotide phosphatases in peripheral blood lymphocytes from control subjects and patients with common variable primary hypogammaglobulinaemia. 612 80


1 2 Next >>