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)

Guinea pig epididymal sperm, incubated for ATPases at pH 7.0 or pH 9.0, localize reaction product on both the periacrosomal segment of the plasmalemma and the outer acrosome membrane. In other species, e.g., rabbit, Ca++-ATPase is identified with the outer acrosome membrane. It may transport Ca++ into the acrosome for activation of enzymes released during the acrosome reaction. The neutral ATPase is demonstrable on the periacrosomal plasmalemma and possibly modifies Ca++ concentration in the fluid around the acrosome. In guinea pig sperm, Ca++-ATPase is sensitive to centrifugation or washing of sperm which indicates that the ductal fluid has unusual properties for preservation of the acrosome. Inhibition of the enzyme by these treatments suggests that conditions on the plasmalemmal surface affect the acrosome membrane. Inability to separate reaction product on the plasmalemma from that on the acrosome membrane may be due to migration of reaction product across the periacrosomal space. However, the ATPases are elicited in the guinea pig under the same conditions as in other species. The pH 9.0 enzyme requires Ca++ while the enzyme at pH 7.0 has no ion specificities. Demonstration of these enzymes indicates that mechanisms of acrosome activation, similar to those in other sperm, are relevant to the guinea pig.
Anat Rec 1978 May
PMID:Identification of phosphates on the membranes of guinea pig sperm. 2 98

The effect of 24 and 48 hours' cold stress on the hamsters' adrenomedullary follicles and on the medullary ATPase activity was studied by light and electron microscopy. Only norepinephrine cells were depleted after this stress, and exocytosis seemed to be the mechanism involved in the release of catecholamine. Follicles containing these cells expanded and their lumina became narrow. A few other cellular and follicular changes also occurred and are described. ATPase activity was apparent in control organs along the endothelial linings, in neural elements and macrophages, and in approximately 40% of the linings of follicular lumina. Cold stress did not alter this pattern. These results have been compared with previous findings and the possible functions of the follicular lumina are discussed. It is concluded that they are unlikely sites for catecholamine storage or release.
Anat Rec 1975 Jan
PMID:Ultrastructural and histochemical study of the adrenal medulla in normal and cold-stressed Syrian hamsters. 12 1

Intact soleus and extensor digitorum longus muscles in the rat were freely grafted to the contralateral leg after either no preliminary treatment or 14 days prior denervation. Normal muscle grafts during the first week were characterized by a central zone of degenerating original muscle fibers (disappearing by 7-9 days) and a peripheral zone, containing regenerating muscle as well as small numbers of surviving original muscle fibers. A radial gradient of regeneration was establihed, with more mature muscle at the periphery and less mature muscle toward the center. Denervated grafts were characterized by rapid degeneration (within 2-3 days) of original muscle fibers in the central area, rapid appearance of regenerating muscle fibers (e.g. cross striations by 5 days) with uniform levels of differentiation throughout the graft and larger numbers of surviving original muscle fibers at the periphery. During the first week, stages of muscle differentiation in denervated grafts were attained 1-2 days earlier than comparable stages in normal grafts. Later stages of muscle differentiation were similar in both types of grafts. Histochemical studies revealed a loss of enzyme activity (phosphorylase, ATPase and SDH) in the center of early (2-4-day) normal and denervated grafts. Denervated grafts, however, possessed a thicker peripheral rim of enzymatically active surviving muscle fibers than normal grafts. In both types of grafts the old muscle fibers in the center were replaced by enzymatically active regenerating muscle fibers which stained uniformaly (ATPase) until 30 days. By 60 days a mixed fiber pattern had developed. Muscle spindles were found within the grafts.
Anat Rec 1975 Sep
PMID:Regneration in free grafts of normal and denervated muscles in the rat: morphology and histochemistry. 12 50

Infection by bacteriophage T4 has previously been shown to cause a rapid inhibition of the host recBC DNase, an ATP-dependent DNase that is required for genetic recombination in Escherichia coli. We report here the partial purification of a protein ("T4 rec inhibitor") from extracts of T4-infected cells and some characteristics of the in vitro inhibition reaction with purified inhibitor and recBC nuclease. This inhibitory activity could not be purified from extracts of uninfected E. coli. Both the ATP-dependent exonuclease and DNA-dependent ATPase activities of recBC DNase are inhibited by T4 rec inhibitor. Experiments suggest that the inhibitor interacts with the nuclease in a stoichiometric manner. The biological significance of this inhibition is discussed with respect to control reactions in phage-infected cells.
 ...
PMID:Postinfection control by bacteriophage T4 of Escherichia coli recBC nuclease activity. 13 May 1

Enriched fractions of chloride cells with good ultrastructural integrity have been obtained from gill filaments of the euyhaline teleost, Lagodon rhomboides. The branchial epithelium from seawater-adapted fish was dissociated by gentle mechanical means in a Ca++, Mg++-free balanced salt solution. Density gradient centrifugation of the mixed cell suspensions through a Ficoll gradient yielded a fraction containing between 50 and 70% chloride cells. This fraction showed a 3- to 4-fold enrichment over comparable gill homogenate values for sodium plus potassium-activated adenosinetriphosphatase, (Na+, K+ ATPase), an enzyme concentrated in chloride cells. Isolation of chloride cells from fish adapted to one-third seawater was less successful, due to the smaller size and reduced number of these cells, although fractions with at least a 2-fold enrichment of the enzyme were obtained. These results continue to support the belief that chloride cells are responsible for osmoregulatory activity associated with the branchial epithelium of teleosts and that this vital function is mediated through the activity of the transport associated enzyme, Na+, K+-ATPase, the specific activity of which increases with osmotic stress.
Anat Rec 1978 Mar
PMID:Rapid isolation of chloride cells from pinfish gill. 14 38

The histochemical characteristics, cross-sectional area and capillary of the skeletal muscle fibers of the anterior and posterior regions of the superficial masseter and the temporalis muscles are described for juvenile and adult rhesus monkeys of both sexes. Slow twitch fatigue resistant (S), fast twitch fatigue resistant (FR) and fast twitch fatigable (FF) fibers were found in varying proportions throughout the muscles; however some fibers with an intermediate myofibrillar ATPase activity were observed in the anterior masseter. No significant differences for any of the variables were found between male and female juveniles for a specific muscle sample site. However, considerable variation was found between juvenile and adult and between adult male and female monkeys in the percentages of different fiber types and the cross-sectional area of fibers in specific regions of the superficial masseter and temporalis muscles. We conclude from these observations that significant differences in function exist both within and between the different masticatory muscles of rhesus monkeys. Functional differences may result from the pronounced sexual dimorphism evident in the dentofacial complex of the rhesus monkey.
Anat Rec 1979 Mar
PMID:Histochemical characteristics of the masseter and temporalis muscles of the rhesus monkey (Macaca mulatta). 15 57

Samples of the rectus abdominis muscle were taken from Sprague-Dawley rats at 0, 3, 6, 6, 12, 15, 18, and 21 days of pregnancy, and at 1, 3, 6, 9, 12, and 15 days of postpartum. Sections were incubated for actomyosin adenosine triphosphatase activity following preincubation at a basic pH. Muscle fibers within a unit area of each sample were identified as to fiber type according to their enzyme activity, and the population of each type counted. The proportion of each fiber type was calculated and the diameter of 24 fibers of each type measured. No changes were noted in the muscle fiber proportions through the course of the experiment. Differential changes in muscle fiber diameters were noted in each of the three muscle fiber types. Slow oxidative fibers underwent an increase in diameter through the last half of pregnancy. The diameter was further increased as stretch of the muscle was released after birth, and did not decrease in the postpartum period. Fast glycolytic fibers decreased in diameter during the last half of pregnancy, but returned to the prepregnancy diameter in the first postpartum day. The diameter of the fast oxidative glycolytic fibers remained unchanged through the course of pregnacy and in the postpartum period.
Anat Rec 1979 Nov
PMID:A study of the effect of pregnancy on muscle fibers of the rectus abdominis muscle of the rat. 15 48

Pieces of rat and human gastric mucosa were fixed in glutaraldehyde and paraformaldehyde and were processed by the methods of Wachstein-Meisel and of Ernst for the cytochemical demonstration of adenosine triphosphatase (ATPase) and p-nitrophenylphosphatase (NPPase) respectively. Electron microscopic examination of reacted sections revealed the ATPase reaction to be localized to the plasmalemma and to mitochondrial cristae and the NPPase reaction to the plasmalemma. The tubulovesicles were unreactive. By thus demonstrating a cytochemical difference between the plasmalemma and tubulovesicle membrane, this study suggests that the tubulovesicles do not represent an extension of or reserve of mature plasmalemma. If the tubulovesicles represent a reserve of membrane that can be rapidly utilized to expand the plasmalemma, then these studies suggest that additional membrane constituents are added, activated, or unmasked in the process.
Anat Rec 1976 Feb
PMID:Demonstration of a cytochemical difference between the tubulovesicles and plasmalemma of gastric parietal cells by ATPase and NPPase reactions. 17 59

The activity of the electrolyte transport enzyme, sodium, potassium-activated adenosine triphosphatase (Na+,K+-ATPase), in the gills of the pinfish, Lagodon rhomboides, increased markedly following transfer of fish from brackish water to seawater. Cytochemical localization of Na+,K+-ATPase via its potassium-dependent phosphatase (K+-NPPase) activity in the branchial epithelium of pinfish adapted to seawater demonstrated that chloride cells are the major sites for the enzyme. Subcellularly, the heaviest depositions of reaction product were observed lining the cytoplasmic membrane surfaces of the labyrinth of anastomosing plasma membrane tubules that ramifies throughout the chloride cell cytoplasm. Enzyme activity was demonstrated also on the cytoplasmic surface of the apical crypt membrane and on the cytoplasmic surfaces of vesicles in the cytoplasm subjacent to the crypt. Deletion of potassium from the cytochemical incubation medium or inclusion of 10 mM ouabain abolished the reaction products associated with these membranes. The significance of these cytochemical results is discussed with reference to current hypotheses of chloride cell function.
Anat Rec 1979 Jan
PMID:Ultracytochemical localization of Na+,K+-activated ATPase in chloride cells from the gills of a euryhaline teleost. 21 85

The Na+,K(+)-ATPase enzyme through its p-nitrophenyl phosphatase activity was localized in the ductuli efferentes of rats. Enzymatic activity was demonstrated along the cytoplasmic side of the plasmalemma of the ductular epithelial cells. The most intense deposition of reaction products was found on the plasmalemma delimiting the lower lateral and basal regions of the cells. The plasma membranes forming the microvilli, apical junctional complexes were devoid of reaction product while the midlateral membranes showed a weak reaction. The enzyme reaction was potassium-dependent and was abolished by addition of 10 mM ouabain to the incubation media. Enzyme activity decreased significantly from proximal to distal regions of the ductules (8,101.47 +/- 274.53, 6,658.95 +/- 269.53 and 4,668.10 +/- 575.41 pmoles p-nitrophenol/mm/h, respectively in initial, conus vasculosus and terminal zones). A unified model for water absorption is proposed in the efferent ductules based upon this data and that of others.
Anat Rec 1992 Oct
PMID:Localization and activity of Na+,K(+)-ATPase in the ductuli efferentes of the rat. 132 78


1 2 3 4 5 6 7 Next >>