SEARCH · Search PubMed

Results for “ADENOSINE TRIPHOSPHATASE”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 433 records · Page 24Linked to original sources

PubMed1991

Histochemical changes in adenosine triphosphatase activity during folliculogenesis and corpus luteum formation and regression in the rat ovary.

Histoenzymological changes in Adenosine triphosphatase (ATPase) activity were studied during folliculogenesis in immature and mature rat ovary. Its presence in oocytes of small follicles and absence in those of large follicles postulate a correlation between their absorptive mechanism during the development of the oocyte. The presence of ATPase activity in the theca, corpora lutea and interstitial gland tissue may be related to the vascular endothelium which is associated with the transport system across the membrane.

Adenosine Triphosphatases↗

PubMed1989

Influence of prolactin on neural and glial cellular adenosine triphosphatases in immature male bonnet monkeys (Macaca radiata, Geoffroy).

The effect of prolactin on specific activities of adenosine triphosphatases (ATPases) in neural and gliar cells of cerebral cortex, cerebellum and pons-medulla of immature male bonnet monkeys was studied. Na+, K+ dependent ATPase was stimulated, while Mg2+ and Ca2+ dependent ATPase activities showed reduction in neural as well as glial cells of cerebral cortex and cerebellum. However, in pons-medulla, Na+, K+ and Mg2+ dependent ATPases showed the same trend in neural and glial cells, respectively, as in the other two regions. The data obtained reveal that prolactin has specific effect on different ATPases, in different regions of the brain.

Adenosine Triphosphatases↗

PubMed1980

Platelet and erythrocyte-membrane adenosine triphosphatase activity in depressive and manic-depressive illness.

An investigation of Mg2+ and (Na+ + K+)-dependent adenosine triphosphatase (ATPase) activities in the platelet and erythrocyte membrane of 44 depressive and 44 manic-depressive patients was carried out before and during (for 3 weeks to less than 1 year) drug treatment. When compared with normal controls (n = 43), the patients showed significantly elevated enzyme activities during both the drug-free and drug treatment periods. No remarkable changes in enzyme activities were observed between the drug-free and drug treatment (even long-term drug treatment) periods. Results suggest an alteration of cell-membrane activity, which may reflect changes in (1) ATP level, (2) cationic balance, (3) membrane phospholipid, or some combination thereof.

Adenosine Triphosphatases↗

PubMed1993

Ventral prostatic phosphomonoesterases and adenosine triphosphatases in hypo- and hyperthyroid albino rats.

Specific activities of prostatic phosphomonoesterases (acid and alkaline phosphatases) and adenosine triphosphatases (Mg2+, Ca2+ and Na+/K+ dependent ATPases) were studied in albino rats, under altered thyroid hormone status. Thyroidectomy induced hypothyroidism decreased the specific activities of acid and alkaline phosphatases, Na+/K+ and Ca2+ dependent ATPases in ventral prostate. Hyperthyroidism (25 micrograms thyroxine/100g body weight/day for 60 days, im) enhanced the activities of acid phosphatase and Na+/K+ dependent ATPase, while Ca2+ dependent ATPase decreased. The altered thyroid status had no effect on the activity of ventral prostatic Mg2+ dependent ATPase. The data obtained in the present study showed differential and specific responses of various ventral prostatic phosphatases to the hypo or hyperthyroid status. The study also shows the necessity of an optimum level of thyroid hormones to maintain the normal activities of these enzymes and their secretory function in ventral prostate.

Adenosine Triphosphatases↗

PubMed1975

Differential effects of lipid depletion on membrane sodium-plus-potassium ion-dependent adenosine triphosphatase and potassium ion-dependent phosphatase.

The phospholipid-dependence of the (Na-++K-+)-dependent ATPase (adenosine triphosphatase) (EC 3.6.1.3) and associated K-+-dependent phosphatase activity (EC 3.6.1.7) have been compared. Unlike the (Na-++K-+)-dependent ATPase activities, the K-+-dependent phosphatase activities of a number of different preparations were not closely correlated with their total phospholipid contents. After partial lipid depletion with a single extraction in Lubrol W the residual ATPase and phosphatase activities were correlated, but their magnitudes were quite different: on average only about 5% of the former remained compared with 50% of the latter. A similar differential effect on these activities was found after extraction with deoxycholate. In contrast with the ATPase, consistent restoration of the phosphatase activity of Lubrol-extracted enzymes by added exogenous phospholipids was not observed. We conclude that, although the K-+-dependent phosphatase may be lipid-dependent, the lipid requirement must be different from that of the complete ATPase system, and this difference should help investigations of their relationship.

Adenosine Triphosphatases↗

PubMed1996

Pentagastrin selectively modulates levels of mRNAs encoding apical H/K adenosine triphosphatase and basolateral Na-K-Cl cotransporter in rat gastric fundic mucosa.

BACKGROUND: Gastrin regulates gastric acid secretion and gastric mucosal cell proliferation. We hypothesized that pentagastrin administration would affect mRNA levels of two membrane proteins that are important during stimulated states of HCl secretion, the basolateral Na-K-Cl cotransporter (BSC) and the apical H/K adenosine triphosphatase (H/K). METHODS: Two groups of Fischer rats received intraperitoneal injections of pentagastrin (2.5 or 25 micrograms/kg) every 8 hours for three doses. A third group served as controls. An additional group received pentagastrin plus the gastrin receptor antagonist (GRA) L740,093. Fundic mucosae were subjected to semiquantitative Northern analysis of mRNAs encoding H/K and BSC. The mRNA for Na/K adenosine triphosphatase (Na/K), a transport protein not involved directly in acid secretion, also was evaluated. RESULTS: Administration of pentagastrin caused dose-dependent increases in levels of mRNAs encoding H/K and BSC but had no significant effect on levels of Na/K mRNA. Administration of GRA prevented the pentagastrin-induced changes in mRNA levels for these transporters. CONCLUSIONS: Pentagastrin administration selectively up-regulates levels of mRNA encoding membrane proteins involved in acid secretion. The up-regulation of the mRNAs encoding BSC during pentagastrin stimulation indicates that regulation of basolateral Cl- movement may be as important as the regulation of apical H+ movement under stimulated states.

Acids↗

PubMed1975

On the specificity of the histochemical technique for sarcoplasmic reticular adenosine triphosphatase: a light and electron microscopic study.

The specificity of the histochemical localization of the calcium activated adenosine triphosphatase (ATPase) activity of the sarcoplasmic reticulum (SR) at pH 7.4 was studied using a calcium-citro-phosphate technique. The latter involves the splitting of ATP by ATPase producing phosphate ions which then react with calcium and citrate to form an insoluble reaction product. This reaction product was detected by both light and electron microscopy. Light microscopic examination showed a darkly stained continuous reticular pattern of reaction product which surrounded individual myofibrils. This reticular pattern of reaction product was distinctly dissimilar to that found when the histochemical reactions for mitochondrial or myofibrillar ATPase were performed. Ultrastructural investigations demonstrated the presence of discrete foci of electron dense reaction product in close association with the membranes of the SR in striated muscle fibres. Only occasional flecks were seen in the vicinity of mitochondria or myofilaments. The possibility is considered that the reticular pattern of staining achieved by the calcium-citro-phosphate technique may reflect the distribution of the "extra ATPase" of the SR, an enzyme implicated in the process of calcium uptake and muscle relaxation.

Adenosine Triphosphatases↗

PubMed1988

Isolation of a sixth dynein subunit adenosine triphosphatase of Chlamydomonas axonemes.

This study of the axoneme led to the identification of a previously unknown adenosine triphosphatase (ATPase), which is likely a major component of inner dynein arms. The ATPase was isolated from a soluble fraction of axonemes obtained from pf 28, a Chlamydomonas mutant lacking the outer dynein arms. The activity hydrolyzed up to 2.3 mumol of ATP.min-1.mg-1 of protein (at pH 7.2, in the presence of both Ca++ and Mg++), had a sedimentation coefficient of 11S in sucrose gradient, and cosedimented with four polypeptides of apparent molecular weight 325,000, 315,000 140,000, and 42,000. Several arguments indicate that the new ATPase is a component of the inner dynein arms. Three or four polypeptides cosedimenting with the activity belong to a group of axonemal components that are deficient in the axonemes of pf 23 and pf 30, two mutants that display different levels of inner dynein arm deficiency. The 42,000 component is axonemal actin, a subunit of two other inner dynein ATPases. The two polypeptides of molecular weight greater than 300,000 have electrophoretic mobility similar to that of high molecular weight components of outer and inner dynein arms. In spite of some similarities each ATPase isolated from inner or outer arms is composed of a different set of polypeptides. Different ATPases may be required for the modulation of localized sliding of adjacent outer double microtubules in the axoneme.

Actins↗

PubMed1977

Adenosine triphosphatase located on unstimulated human small lymphocyte cell membranes.

This study was undertaken to localize the enzyme sodium-potassium dependent adenosine triphosphatase in unstimulated human small lymphocytes using the histochemical technique of McClurkin [1964]. The substrate adenosine 5' triphosphate is hydrolyzed by the ATPase resulting in a lead phosphate precipitate at the site of enzyme action, subsequently visualized as lead sulphide. The enzyme was demonstrated in three different patterns, and for each donor the pattern was constant both on all four of the test slides, and on different occasions. The patterns observed were: clusters of granules related to the cell membrane; positive staining localized to portions of the cell membrane, and, less commonly, the whole cell circumference. The significance of this distribution may relate to areas with large numbers of antigen recognition sites on the lymphocyte membrane.

Adenosine Triphosphatases↗

PubMed1969

The adenosine triphosphatase and calcium ion-transporting activities of the sarcoplasmic reticulum of developing musce.

1. The ATPase (adenosine triphosphatase) specific activity and the total nitrogen content of the myofibrillar fraction per g. wet weight of rabbit longissimus dorsi muscle increased steadily during the late foetal stages and the first few weeks after birth. 2. The ATPase specific activity of the sarcoplasmic-reticular fraction isolated by a sucrose-density-gradient procedure rose to a sharp peak 8-10 days after birth and then declined to the adult value, which was about 25% of the maximum. 3. The peak in ATPase activity was a feature of the sarcoplasmic reticulum isolated from muscle, and the time at which it occurred in relation to birth was related to the degree of development and the activity pattern of the muscle. 4. The peak in ATPase activity of the sarcoplasmic reticulum occurred at an earlier age if newborn animals were made to exercise earlier than was normal. 5. The ;extra' ATPase associated with the sarcoplasmic reticulum and the ability to concentrate Ca(2+) increased in a similar manner over the period of development studied. 6. It is postulated that the Ca(2+)-transport system of the sarcoplasmic reticulum consists of two components, namely the ATPase and the system coupling this enzyme to Ca(2+) transport. During development the ATPase develops first and has almost reached maximum activity in the longissimus dorsi muscle of the rabbit after 8-10 days. Subsequently the activity of the coupling system rises rapidly, leading to an increase in the capacity and efficiency of Ca(2+) transport.

Adenosine Triphosphatases↗

PubMed1977