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)

Vasodilator responses to acute intra-arterial infusions of K+ are attenuated in dogs with chronic one-kidney perinephritic hypertension in rats with chronic two-kidney Goldblatt hypertension, and in men with essential hypertension. There is evidence that K+ evokes vasodilation by stimulating vascular smooth muscle membrane Na+-K+-activated adenosine triphosphatase, thereby increasing activity of the cellular Na+-K+ electrogenic pump. We therefore proposed that there may be an underlying decrease in the operation of this pump in vascular smooth muscle of hypertensives. The operation of the cellular Na+-K+ pump may be estimated by measurement of rubidium uptake. Thus, so further investigate our hypothesis, we measured 86Rb uptake in small mesenteric arteries and splanchnic veins from 12 dogs with chronic uncomplicated one-kidney perinephritic hypertension and from 12 normotensive control dogs. Vessels were excised under thiamylal anesthesia and incubated in cold medium (plasma or Krebs-Henseleit solution) for sodium loading and then the velocity of 86Rb uptake was estimated in the absence of or in the presence of ouabain, a specific inhibitor of the Na+-K+ pump. In neither arteries nor veins was there evidence for differences between hypertensives and normotensives in the ouabain-insensitive uptake of 86Rb. In contrast, the ouabain-sensitive 86Rb uptake was depressed by 42% in arteries (P less than 0.05) and by 49% in veins (P less than 0.01) from hypertensive dogs, if incubated in the dog's own plasma. These results indicate that the activity of a ouabain-sensitive Na+-K+ pump may be depressed in vascular tissue from dogs with chronic one-kidney perinephritic hypertension. Because the Na+-K+ pump in vascular smooth muscle is probably electrogenic, such an abnormality, by partially depolarizing the muscle cell membrane, would help to account for the elevated vascular resistance found in these dogs.
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PMID:Depressed function of a ouabain-sensitive sodium-potassium pump in blood vessels from renal hypertensive dogs. 13 55

In rats with ligation of the left coronary artery changes in ATPase activity and structure of cardiac myosin in both ischaemic and non-ischaemic zones of the myocardium were followed. In control animals, ATPase activity and the structure of the myosin molecule in right and left ventricles did not differ. Non-specific factors, such as anaesthesia and thoracotomy, can result in a decrease or an increase in ATPase activity respectively. One hour after ligation of the left coronary artery ATPase activity increased in the right, non-ischaemic myocardium and there was a significant right-to-left difference. Four hours after ligation, ATPase activity in both ventricles significantly decreased and the right-left difference disappeared. Within 48 h, normal values were found only in the non-ischaemic right ventricle. Ligation of the left coronary artery results after 48 h in the formation of structural alterations in cardiac myosin, primarily in the left, ischaemic myocardium. These changes are characterised by the formation of myosin aggregates, which have a significantly lower ATPase activity in comparison with monomeric myosin.
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PMID:Structural and enzymatic properties of cardiac myosin in ischaemic and non-ischaemic regions of the rat myocardium. 13 50

Guinea pig hindlimbs were unilaterally immobilized at resting length to evaluate histochemical, biochemical, and contractile properties of immobilized muscle. Contralateral limbs remained unrestrained. Four weeks later contractile properties were measured under chloral hydrate anesthesia. Average time-to-peak tension of the immobilized soleus was 30% less, whereas that of the gastrocnemius was not significantly changed relative to contralateral muscles. Immobilized soleus muscles acquired as much as 25% fibers with high alkaline myofibrillar adenosine triphosphatase activity; these fibers do not occur in the normal muscle. Neither the immobilized soleus nor gastrocnemius fatigued more quickly than their contralateral counterparts. In the immobilized gastrocnemius myofibrillar protein (mg/g muscle) decreased to 76% and maximum tetanic tension to 70% of contralateral values. However, tetanic tension per gram wet muscle weight or 100 mg myofibrillar protein was significantly greater in the immobilized gastrocnemius. No specific factor responsible for the increased tetanic tension could be identified.
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PMID:Properties of immobilized guinea pig hindlimb muscles. 13 3

Enzymatic properties of erythrocyte membranes in Duchenne muscular dystrophy (DMD) and malignant hyperthermia (MH), two genetically determined abnormalities of skeletal muscle, were examined. Acetylcholinesterase (AChE) and ATPase activities were chosen for investigation since alterations in these enzymes have been demonstrated in animal models of dystrophy. A significant decrease in Na+,K+-ATPase activity was noted in DMD patients and a number of possible DMD carriers, suggesting that this enzyme may provide a useful marker of the carrier state in carriers not exhibiting an elevation in plasma creatine phosphokinase activity. No abnormalities in AChE were demonstrable in any of our DMD patients, indicating that human dystrophy is biochemically distinct from certain animal models of dystrophy (e.g., dystrophic mice) where erythrocyte AChE is decreased. In contrast, evidence was found in two known MH carriers, who had normal erythrocyte ATPase activities, for the presence of an altered membrane AChE characterized by an increase in substrate affinity and a large decrease in maximal hydrolytic rate. While the exact relevance of this membrane defect, if any, to the pathogenesis of MH remains to be seen, the presence of this modified enzyme may serve to identify those individuals in a family where a positive history of MH exists who are at risk of developing a hyperthermic crisis during anesthesia.
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PMID:Erythrocyte membrane enzyme abnormalities in two hereditary disorders of muscle. 23 Oct 77

1. Rats were prepared under anaesthesia with non-occlusive catheters in hepatic portal vein (HP) and inferior vena cava (VC) and maintained under standard conditions. 2. Each rat received a series (3 day intervals) of 30 min infusions of different solutions or sham into HP or VC. Oral intake of 0.15 M-NaCl and water were measured for 30 min. Significant change in drinking behaviour was assumed when the response to HP infusion differed from both sham and VC infusion. 3. Saline drinking was inhibited by HP infusion of 1 M- or 2M-NaCl, an effect blocked by right vagotomy or by addition of 16 mM-KCl to the infusate. 4. Saline drinking was increased and water drinking decreased by HP infusion of 2 M-glucose but not sucrose or fructose. 5. Saline drinking was decreased by HP infusion of deoxy-D-glucose to inhibit glucose utilization or ouabain to inhibit (Na4-K+) ATPase. 6. Results are consistent with the presence of afferent nerve terminals in hepatic portal vessels which are sensitive to change in NaCl or glucose concentration and which, in response thereto, alter drinking behaviour. The effects of NaCl and glucose on the discharge rate of the nerve terminals may be interpreted in terms of changing activity or electrogenicity of a Na pump but changes in membrane conductance or Na influx cannot be ruled out.
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PMID:Hepatic portal vein infusion of glucose and sodium solutions on the control of saline drinking in the rat. 62 89

Synaptosomes, or nerve-ending particles, were isolated from the cerebral cortices of young rats by homogenization, differential centrifugation, and density-gradient centrifugation. The sodium-potassium-activated adenosine triphosphatase enzyme system [(Na+ plus K+)-ATPase] of these particles is believed to represent in vitro the sodium-potassium pump of the nerve terminal. Suspensions of synpatosomes were equilibrated with air containing various concentrations of halothane and enflurane, as determined by gas chromatography. Clinical concentrations of the anesthetics had no effect on (Na+ plus K+)-ATPase activity. Fourteen per cent halothane and 14.8 per cent enflurane in the gas phase resulted in 12 and 10 per cent inhibition, respectively, of (Na+ plus K+)-ATPase activity. These data confirm that interference with active cation transport by inhibition of neuronal (Na+ plus K+)-ATPase is not related to the mechanism of halothane or enflurane anesthesia. (Key words: Anesthetics, volatile, halothane; Anesthetics, volatile, enflurane; Metabolism, enzymes, ATPase; Nerve, synaptosomal ATPase; Theories of anesthesia, ATPase.).
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PMID:The effects of halothane and enflurane on rat brain synaptosomal sodium-potassium-activated adenosine triphosphatase. 80 97

The aim of this study is to investigate the effect of ouabain (inhibitor of Na-K ATPase) in the myocardial uptake and clearance of 201Tl and 99mTc MIBI using rats. Time activity curves of three groups were measured by CsI miniature detector for 15 min after the administration of each radiopharmaceutical. Groups were divided as follows; 1) control group (CON group), 2) early phase as 15 min after the administration of ouabain (OU15 group), and 3) late phase as 120 min after the administration of ouabain (OU120 group). Main organs of rats including myocardium were resected at 1 min and 15 min after the administration of 201Tl or 99mTc MIBI under the anesthesia of pento-barbital sodium. The uptake (%ID/g) of 201Tl or 99mTc MIBI was measured by well type scintillation counter. The uptake of 201Tl of OU15 group was significantly higher than CON group (OU15: 10.81 +/- 1.90, CON: 1.86 +/- 0.42) and cleared more rapidly. On the contrary, OU120 group showed lower uptake (1.70 +/- 0.21) and slower clearance than OU15 group. Time activity curve of OU15 group indicated the accelerated washout compared with CON group. However, OU120 group showed significantly the reduced washout (CON group: 19%, OU15 group: 22%, OU120 group: 9%). On the other hand, the uptake and time activity curves of 99mTc MIBI were not influenced by ouabain administration. In conclusion, myocardial uptake and clearance of 99mTc MIBI were not related to Na-K ATPase activity, while those of 201Tl were markedly influenced by Na-K ATPase.
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PMID:[Effects of ouabain on 201Tl and 99mTc MIBI kinetics in rat myocardium--in vivo study using miniature CsI detector]. 133 78

Maximum heart rates (HR) of three soricine shrews and six other small mammals were measured in response to a single supramaximal dose of isoproterenol (Iso) under urethan anesthesia. The highest HR, 1,043 +/- 66 (SD) beats/min (n = 3), was in least shrew (Sorex minutus, mean body mass 3.02 +/- 0.81 g). Maximum HRs of common shrew (Sorex araneus, 7.16 +/- 1.54 g) and water shrew (Neomys fodiens, 12.80 +/- 1.54 g) were 938 +/- 29 (n = 7) and 887 +/- 21 (n = 6), respectively. In general, maximum HRs of soricine shrews and other small wild mammals followed the common mammalian pattern, fHmax/Iso = 443 x Mb-0.14, determined by body size. The exponent for this equation is smaller than that of resting HR (-0.25) (Stahl, J. Appl. Physiol. 22: 453-460, 1967), predicting crossover at approximately 3 g body mass. However, resting HRs of small mammals were clearly lower than expected on the basis of body mass. Lowering resting HR below the common mammalian level, with concomitant increase in stroke volume, seems to be a prerequisite for small mammals to regulate cardiac output against the ceiling of maximum HR. Electrophoretic analysis showed that the myosin of shrew ventricles is different from those of rodent species. In native conditions, shrew myosin, designated V1', migrated faster than the V3 and V1 forms of rat heart. On SDS gradient gel the single heavy chain of shrew myosin migrated slower than the alpha- or beta-chains of rat ventricle. Differences in the molecular weight of light chains were also noted between small mammals. Despite the notable differences in myosin composition, myosin-ATPase activity of the shrew hearts was similar to that of mouse and rat heart. Because duration of isometric contraction was inversely related to resting and maximum HRs, it was concluded that in the small mammals rate and duration of contraction are determined mainly by the release and uptake rate of myoplasmic Ca2+ and less by myosin-ATPase activity.
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PMID:Maximum heart rate of soricine shrews: correlation with contractile properties and myosin composition. 153 6

The origin of the severe diarrhea appearing after intestinal denervation or transplantation was studied on the 3rd and 14th postoperative days in 5 groups of dogs undergoing total or partial denervation. The net movements of water and electrolytes were investigated by employing an experimental model of intestinal perfusion in isolated loops in vivo. The active uptake of phenylalanine and beta-methylglucoside and Na(+)-K(+)-ATPase activity were used for in-vitro evaluation. Bacteriologic and histological specimens were also taken. Following total denervation with anastomosis, a considerable loss of water and electrolytes as well as numerous E. coli were found in the entire small intestine. This net secretion is due to the stagnation of bacteria in the presence of complete denervation and the absence of food since the animals in this group could not eat properly following general anesthesia and surgery. Consequently, peristalsis was not stimulated and bacterial overgrowth occurred. In the group denervation with pseudo-anastomosis, perfusion studies showed a decrease of absorption in the jejunum and minimal but significant secretion in the ileum. A high number of E. coli was also present. Since the mucosa remained intact, nutrition per os was resumed in the immediate postoperative period and excessive water and electrolyte loss was avoided. The high number of bacteria was due to a decrease in intestinal motility since complete denervation was performed. In the denervation group, water and electrolyte movements were identical to those observed in the preceding group but the entire intestine remained sterile.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Origin of secretions after denervation of the small intestine in the dog]. 159 44

Sheep under general anesthesia had their left and right latissimus dorsi muscles mobilized for paraneuroelectrode and pulse generator implantation. After a 10-day recovery period, the left-side muscles were stimulated with a gradually increasing duration and rate over 3 months. At 4 months after operation, the tendinous end of each latissimus dorsi muscle was freed from its humeral insertion and attached to a strain gauge force transducer. Both left and right latissimus dorsi muscles, from each animal, were stimulated to contract for 2 hours for the fatigue study before being isolated, trimmed, and weighed. Frozen tissue biopsies were used to determine creatine phosphate, adenosine triphosphate, lactate, and glycogen content and muscle myosine ATPase, and succinate dehydrogenase activities. The arterial diameter in the conditioned muscle was 30% larger than that of the control muscle and had a 40% higher blood flow at rest. A three- to fivefold increase in blood flow during the fatigue test was observed. The force decreased 47% for the conditioned muscle and 91% for the control muscle. The mass and cross-sectional area of conditioned and unconditioned muscles were similar. Electric conditioning increased fatigue resistant fiber content from 33% to 92%, as evidenced by myosine ATPase activity. During the early phase of the fatigue test, higher glucose uptake but significantly lower lactate production were found for the conditioned muscle. This study indicates that it is possible to produce fatigue resistant muscle with preserved force and mass. In addition to skeletal muscle fiber transformation, metabolic adaptations appear to be important factors for fatigue resistance of skeletal muscle.
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PMID:Fatigue resistant muscle with preserved force and mass for cardiac assist. 180 6


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