Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.6.1.3 (ATPase)
65,361 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The administration of trivalent and hexavalent chromium compounds produced inhibition of the activity of succinic dehydrogenase, adenosine triphosphatase and acid phosphattase accompanied by cellular degeneration with complete absence of spermatocytes in the testis of rabbits. The biochemical and histological changes were more marked in the animals treated with the trivalent chromium than those exposed to hexavalent chromium and were progressive with the duration of exposure.
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PMID:Comparative toxicity of trivalent and hexavalent chromium to rabbits. III. Biochemical and histological changes in testicular tissue. 15 92

The authors studied the histochemical and ultrastructural alterations of human muscles after spontaneous rupture of the tendon. Both succinate dehydrogenase (in type 1 fibres), and ATPase (in type 2 fibres) activity decreased in all injured muscles. In the intact antagonists and in contralateral muscles alterations were not found. The creatine phosphokinase and aldolase activity were decreased also in the injured muscles. The lactate dehydrogenase activity was various both in affected and in unaffected antagonists muscles. 2 weeks or more after the rupture of the tendon, in the injured muscles the number of type 1 fibres were decreased and therefore a statistically significant type 2 fibre predominance occurred. Ultrastructurally the disruption and disorientation of the myofibrils, streaming and disorganisation of Z line were found. The sarcolemma was arranged, the sarcoplasmic reticulum was dilated; both normal, pycnotic and enlarged mitochondria were observed. The motor end-plates were not discernible.
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PMID:Histochemical and ultrastructural study of human muscles after spontaneous rupture of the tendon. 15 81

Histochemical profiles of individual muscle fibres were established using myosin adenosine triphosphatase (myosin ATPase), succinate dehydrogenase (SDHase), and glycogen phosphorylase (GPase) reactions in three muscles (semitendinosus, diaphragm, and pectoralis transversus) of the horse and dog. The major histochemical difference between fibres lies in their myosin ATPase activity; fibres can be subdivided into those with a high and those with a low activity. In horse muscle, all fibres have a high activity of GPase. In the diaphragm and pectoralis transversus, all fibres have a high SDHase activity, but fibres with a low activity of SDHase are also present in samples of the semitendinosus. In dog muscle, all fibres have a high SDHase activity; myosin ATPase low-reacting fibres also have a low activity of GPase. There is a greater fractional area of myosin ATPase high-reacting fibres in the pectoralis transversus and semitendinosus of thoroughbred horses and greyhounds (breeds selected for high speed running) and in the diaphragm of greyhounds. In adults this feature does not appear to be due to training, as are the differences in aerobic and anaerobic capacity (shown in other studies). The preponderance of myosin Atpase high-reacting fibres suggests that there may be differences in the nervous systems of athletes and non-athletes. It is concluded that the proportions of fibre types in muscles are related to the functions of muscles and of their parts. No sex differences or detraining effects were apparent, although the value for the proportion of fibre types (as differentiated by the myosin ATPase reaction) in the limb muscles of thoroughbred crosses lies between those of thoroughbreds and non-thoroughbreds.
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PMID:Differences in the histochemical properties of skeletal muscles of different breeds of horses and dogs. 15 95

1. Serial sections of flexor digitorum longus muscle (f.d.l.) of the cat were examined histochemically for four enzyme systems: adenosine triphosphatase (ATPase) with alkaline and acid pre-incubation, phosphorylase and succinic dehydrogenase (SDHase).2. The number of types into which fibres should be divided was assessed by estimating enzyme reaction intensity from measurements of light transmission through photomicrographs. It was concluded that in general the enzyme reaction intensities of fibres were distributed continuously. However, the distribution histograms showed two (phosphorylase and SDHase) or three (acid and alkaline ATPase) clear peaks. Eighteen combinations of reaction intensities (profiles) were seen of which eight were very rare. The distribution of profiles differed between individuals but were similar in right and left muscles.3. Areas of fibres were measured from muscles which had been fixed at the length at which twitch tension was maximal. The variance in fibre area with any one profile was significantly less than the variance in fibre area of all fibres within a muscle. There were significant differences between the mean areas of fibres with different profiles.4. If only three enzyme reactions are considered (acid and alkaline ATPase and phosphorylase) the majority of fibres fall into one of the three classes commonly accepted for other muscles. The remainder would fit into this classification with the minimal assumption of only one error of fibre typing resulting from the continuous distributions of enzyme reaction intensities. The SDHase reaction was not strongly correlated with the three classes and could be used to divide the fibres further into six groups. Differences between means of fibre areas were significant for all pairs out of these six groups except one.5. The grouping may be considered to reflect a dual system of enzymes, the two systems being (a) ATPases and phosphorylase, (b) SDHase. A possible role of nervous activity in determining this dual system is discussed. The hypothesis involves two partly independent characteristics of motoneuronal activity: (a) the frequency of impulses, and (b) the total number of impulses.6. The measurements are correlated with other physiological variables in the individual animals. The mean areas of fibres in all groups increased with body weight. There were changes in the proportions of light and dark SDHase fibres related to weight. The total area contributed by dark alkaline ATPase fibres decreased and that by intermediate alkaline ATPase fibres increased with increasing twitch time to peak.7. Specific tension of the group of slower muscle fibres in f.d.l. was estimated to be 0.29 N.mm(-2) compared with 0.39 N.mm(-2) for the faster fibres.
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PMID:Histochemical reactions of fibres in a fast twitch muscle of the cat. 15 59

Ligature and section of the abdominal aorta results in only minor and temporary functional and metabolic changes in the slow soleus muscle of the rat. A very small decrease in maximal tetanic tension corresponds to a few scattered areas of damaged and necrotic muscle fibres, in which decreased succinic dehydrogenase and loss of phosphorylase activity was observed. A new experimental approach, i.e. ligature and section of the abdominal aorta combined with terminal devascularisation, preserving intact tendons and innervation of the muscle causes maximal muscle ischemia, followed by an almost complete loss of tetanic tension output, marked shortening of contraction time and profound morphological and histochemical changes. The decrease in succinic dehydrogenase and ATPase activities and loss of phosphorylase activity occur in the majority of degenerating muscle fibres except for a thin rim of peripheral fibres during the first 4 days. Subsequently, the contractile properties recover gradually and enzyme activities reappear in the regenerating muscle fibres simultaneously with new revascularisation. Thirty days after the operation all the parameters observed returned to control values.
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PMID:Effect of ischemia on contractile and histochemical properties of the rat soleus muscle. 15 45

Differential centrifugation of rat small intestinal homogenates produced a crude brush border (BB) fraction that was enriched 15-fold for the marker enzymes, alkaline phosphatase and sucrase; contamination with mitochondrial enzymes, monoamine oxidase and succinate dehydrogenase, was minimal. ATP hydrolysis by this BB fraction was stimulated by addition of several anions to the incubation medium: HCO3 and Cl were equally effective in this regard, with NO3, NO2, SO4, and acetate being less stimulatory. SCN and CNO inhibited ATPase activity, whereas the divalent anion SO3 was stimulatory at low concentrations (less than 25 mM) but inhibitory at 100 mM. Maximum anion stimulation was observed at a Mg concentration of 0.5 mM, and pH optimum was 8.5. Kinetic analysis showed that HCO3 increased the Vmax without altering the Km for ATP; the Ka for this effect of HCO3 was 35 mM. This enzyme activity was completely inhibited by 20 mM L-phenylalanine, 10 mM L-cysteine, and 3 mM EDTA, compounds that also inhibited intestinal alkaline phosphatase. These results demonstrate the presence of anion-stimulated ATPase activity in rat small intestinal brush border and suggest that this activity may be related to intestinal alkaline phosphatase. The role of this enzyme in intestinal transport is not known, but could relate to the regulation of intestinal absorption and secretion.
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PMID:Anion-stimulated ATPase activity of brush border from rat small intestine. 15 3

A new technique for isolating fragmented plasma membranes from skeletal muscle has been developed that is based on gentle mechanical disruption of selected homogenate fractions. (Na+ + K+)-stimulated, Mg2+-dependent ATPase was used as an enzymatic marker for the plasma membrane, Ca2+-stimulated, Mg2+-dependent ATPase as a marker for sarcoplasmic reticulum, and succinate dehydrogenase for mitochondria. Cell segments in an amber low-speed (800 x g) pellet of a frog muscle homogenate were disrupted by repeated gentle shearing with a Polytron homogenizer. Sarcoplasmic reticulum was released into the low-speed supernatant, whereas most of the plasma membrane marker remained in a white, fluffy layer of the sediment, which contained sarcolemma and myofibrils. Additional gentle shearing of the white low-speed sediment extracted plasma membranes in a form that required centrifugation at 100,000 x g for pelleting. This pellet, the fragmented plasma membrane fraction, had a relatively high specific activity of (Na+ + K+)-stimulated ATPase compared with the other fractions, but it had essentially no Ca2+-stimulated ATPase activity and only a small percentage of the succinate dehydrogenase activity of the homogenate. Experimental evidence suggests that the fragmented plasma membrane fraction is derived from delicate transverse tubules rather than from the thicker, basement membrane-coated sarcolemmal sheath of muscle cells. Electron microscopy showed small vesicles lined bu a single thin membrane. Hydroxyproline, a characteristic constituent of collagen and basememt membrane, could not be detected in this fraction.
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PMID:Isolation of plasma membrane vesicles, derived from transverse tubules, by selective homogenization of subcellular fractions of frog skeletal muscle in isotonic media. 15 42

Histochemical and ultrastructural properties of myoid cells in the thymus of the frog were investigated and compared with properties of skeletal muscle fibres. The histochemical reactions of phospholipids, phosphorylase, succinic dehydrogenase and adenosine triphosphatase activities in myoid cells were characterized by considerable variability. Individual myoid cells apparently possess different enzyme activities which correspond to different stages of development, maturity and degeneration of these cells. The mature mononucleated myoid cells have similar enzymatic properties to the fast muscle fibres of the frog. This finding has been extended by ultrastructural observations. Features, typical of fast muscle fibres of the frog, e.g. the presence of the M-line, straight and narrow Z-line and well developed triads were found in the majority of mature myoid cells.
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PMID:Histochemical and ultrastructural properties of myoid cells in the thymus of the frog. 15 83

The serratus metapatagialis (SMP) muscle of the pigeon has been studied histochemically and ultrastructurally. At the gross anatomical level the SMP is clearly divisible into a peripheral whitish band and a red portion comprised predominantly of 'pale' and 'red' fibres respectively. The pale fibres possess low succinate dehydrogenase, low mitochondrial content, absence of subsarcolemmal mitochondrial aggregates, low fat, moderate glycogen, high phosphorylase, low-to-moderate regular myofibrillar adenosine triphosphatase (M-ATPase), activation of M-ATPase following acid preincubation and jagged Z bands. On the basis of these characteristics, these physiologically slow muscle fibres have been termed 'Type I white or slow-twitch glycolytic'. The SMP red fibres, however, possess high aerobic as well as glycolytic capacity, high M-ATPase activity which is labile after acid preincubation and thick but straight Z bands; therefore, they are the 'Type II red or fast-twitch oxidative-glycolytic'.
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PMID:Histochemical and ultrastructural characteristics of a new muscle fibre type in avian striated muscle. 15 9

Trimmed strips of sternomandibularis muscles taken from freshly-slaughtered cattle were placed in an isotonic myograph and cooled to 1 degree C. Spontaneous activity due to neuromuscular irritability was minimized by keeping muscle surfaces moist and anaerobic and was monitored by electromyography. Muscle strips were removed and frozen for histochemical analysis after they had completed their initial phase of cold-induced shortening (several hours). Control strips maintained for an equal time at 24 degrees C rarely depleted the stainable glycogen in any of their muscle fibres so as to become PAS-negative. In chilled muscle strips, however, glycogenolysis was activated in some muscle fibres and they became PAS-negative. In serial sections, most of the PAS-negative fibres exhibited strong ATPase and weak succinate dehydrogenase activity. Fibres with weak ATPase and strong succinate dehydrogenase activity rarely became PAS-negative. These results are in agreement with biochemical reports of a cold-induced (less than 5 degrees C) activation of glycolysis in skeletal muscle post mortem. Investigations on untrimmed lengths of excised sternomandibularis muscle indicated that longitudinal muscle damage caused in cutting muscle strips for the myograph and/or their more rapid rate of initial cooling had facilitated the depletion of stainable glycogen.
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PMID:Low temperature activation of post mortem glycogenolysis in bovine skeletal muscle fibres. 15 72


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