Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.6.3.1 (Mg2+-ATPase)
 1,484 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of long-term ethanol feeding on the activity of (Na + K)-ATPase in cortex and outer medulla and fractional excretion of electrolytes in remnant kidney of adult rats after unilateral nephrectomy were studied. Wistar adult rats were fed 20% (v/v) aqueous ethanol solution as sole drinking fluid for 8-10 weeks. Right kidney was removed under ether anaesthesia. The animals were subjected to an acute NaCl loading by means of a continuous infusion given 2, 7 and 14 days after nephrectomy. Renal handling of electrolytes was estimated from fractional excretion of sodium and potassium. After the infusion the animals were killed and (Na + K)-ATPase and Mg2+-ATPase activities were measured in the cortex and outer medulla of the remnant kidney. Two days after nephrectomy both groups showed a gradual increase of renal (Na + K)-ATPase activity reaching 60 percent at day 14. Mg2+-ATPase activity did not change with respect to basal values. Compared to basal values the fractional excretion of sodium after nephrectomy, dropped in both groups but more significantly in the ethanol-fed rats than in the control group. Fractional excretion of potassium did not change in the control group after nephrectomy while the ethanol-fed group displayed a significative decrease at days 7 and 14. According to our results the rise in renal (Na + K)-ATPase activity is consistent with the renal sodium retention found in ethanol-fed rats.
 ...
PMID:Renal handling of electrolytes and (Na + K)-ATPase activity after unilateral nephrectomy during long-term ethanol feeding. 255 83

The mechanism of the anaesthetic effect of toluene on the central nervous system (CNS) was studied by using rat erythrocyte and synaptosome membranes as nerve cell models both in vitro and in vivo. The activities of the membrane-bound integral enzymes acetylcholinesterase (AChE), total adenosine triphosphatase (total ATPase) and magnesium-activated adenosine triphosphatase (Mg2+-ATPase) were determined. A short-term exposure to 2000 p.p.m. of toluene had an inhibitory effect on the enzyme activities studied. The degree of inhibition in erythrocyte membranes in vitro and in vivo, and in synaptosome membranes in vitro were in good correlation. In in vivo conditions, the synaptosome-bound enzymes were, however, significantly more inhibited by toluene, which indicates that membranes in vivo are even more vulnerable to the toxic effects of organic solvents than they are as isolated membranes in vitro. However, our results show that in vitro experiments can be used to predict the toxic nerve cell membrane effects of organic solvents. Toluene caused similar enzyme inhibitions both in neural cell membranes and in erythrocyte membranes. Thus, even peripheral non-excitable cell membranes, like erythrocytes, can be used as nerve cell membrane models in studies on the mechanism of the anaesthesia caused by solvents.
 ...
PMID:The effect of in vitro and in vivo toluene exposure on rat erythrocyte and synaptosome membrane integral enzymes. 296 6

Normal adult albino and Sprague-Dawley rats, under intraperitoneal Nembutal anesthesia, were used to demonstrate enzymatic activity in the choroid plexus and ventricular ependyma. The brain tissues were perfused or immersed with cold 2% glutaraldehyde and 8% sucrose in 0.1 M cacodylate buffer (pH 7.2-7.4) for 30 min and washed overnight in the same buffer solution., The choroid plexus (lateral and fourth ventricles) and ventricular ependyma (lateral ventricle) were trimmed from the fixed and washed brain tissues, which were frozen and sectioned. For histo- and cyto-chemical study, the sections were immersed in the following incubation media; for Na+, K+-ATPase (ouabain-sensitive, K+-dependent, p-nitrophenylphosphatase: p-NPPase) according to the one-step method of Mayahara et al. (1978): for Mg2+- ATPase, Wachstein-Meisel's incubation medium (1957); for adenylate cyclase (AC), following Araki and Saito's lead citrate method (1979). The cytochemical findings gave the following results. In the choroid plexus, the ouabain-sensitive electron-dense reaction products of NA+, K+-ATPase (p-NPPase) were strongly positive in the microvilli and along the inner surface of microvilli, without showing any Mg2+-ATPase and AC activities, and all three enzymatic activities were positive along the basal plasmalemmas and negative along the lateral and apical (not including microvilli) plasmalemmas. In the ventricular ependyma, Na+,K+-ATPase (P-NPPase) activity was not found, and the reaction product of AC was observed on the apical plasmalemmas and those of Mg2+-ATPase along the basal plasmalemmas. These cytochemical findings are helpful in understanding the regulation of cerebrospinal fluid production through Na+, K+-ATPase (p-NPPase) and cyclic AMP (AC).
 ...
PMID:Cytochemical study on enzyme activity associated with cerebrospinal fluid secretion in the choroid plexus and ventricular ependyma. 611 20

The purpose of this study was to examine muscle plasmalemma which is implicated as the site responsible for the appearance of malignant hyperthermia in human and susceptible strains of animals. In pigs with malignant hyperthermia (MH) the activity of Na+/K+, Mg2+-ATPase, p-nitrophenylphosphatase and Mg2+-ATPase fell significantly during anaesthesia. In the control group the contrary occurred. In both the groups tested there was a marginal rise in the levels of sialic acid. The levels of cholesterol and lysoderivatives were abnormal before the provoking agents were administered but they changed significantly after onset of the MH syndrome. Anaesthesia reduced the phospholipids level in both tested animal groups. Before and after the provoking agents an impoverishment in the polypeptide pattern in the range between 80,000 and 30,000 daltons of mol. wt. in MH susceptible animals occurred. It is postulated that in MH the macromolecular disorganization of the muscle plasma membranes means that defence mechanisms maintaining cell gradients do not work in the presence of provoking agents.
 ...
PMID:Experimental porcine malignant hyperthermia: macromolecular characterization of muscle plasma membranes. 615 Oct 35

The lipid composition and fluidity of plasma membranes have been studied at different stages of liver regeneration (4, 15 and 24 h after surgery). The phospholipid and fatty acid composition is not modified, whereas the cholesterol/phospholipid ratio is lower with respect to control membranes. The modification of the physical properties of the membranes has been studied directly by EPR analysis and indirectly by temperature dependence and cooperativity of some membrane-bound enzymes (Mg2+-ATPase, (Na+ + K+)-ATPase and 5'nucleotidase). Surgical operation or anaesthesia alone causes an early increase in fluidity; such an effect appears to be markedly reduced at a later stage. There seems to be a marked effect of regeneration on plasma membrane fluidity 15 h after partial hepatectomy when several parameters--surface fluidity, cholesterol/phospholipid ratio, and 5'-nucleotidase activity in the presence of concanavalin A -- are modified and indicate an increase in membrane fluidity. It is suggested that this modification of membrane properties could be related to the proliferative process.
 ...
PMID:Plasma membrane changes associated with rat liver regeneration. 624 90

To evaluate the relationship between erythrocyte injury and intracellular calcium ion overload, and the protective effect of propofol on erythrocytes during cardiopulmonary bypass (CPB). 40 children with congenital heart diseases who underwent surgical repair under CPB were included. The patients were randomly divided into two groups: control group (group C) and propofol group (group P). Anesthesia was maintained in the patients with 6 mg/kg/h propofol in Group P, and those in the Group C inhaled 1%-2% isoflurane. The blood samples were taken before CPB, 30 min after CPB, at the end of CPB, and 2 h and 24 h after CPB to measure the content of erythrocyte intracellular calcium ion (E-Ca2+), Ca2+-Mg2+-ATPase and Na+-K+-ATPase activities, index filtration of erythrocytes (IF), mean corpuscular volume (MCV) and the concentration of plasma free hemoglobin (F-Hb). Results showed that in the control group, E-Ca2+, IF, MCV and F-Hb were gradually increased and Ca2+-Mg2+-ATPase and Na+-K+-ATPase activities were decreased. The increase of E-Ca2+ was linearly paralleled to IF, MCV and F-Hb. In propofol group, all the above-mentioned parameters were significantly improved (P<0.05). This study suggests that erythrocyte injury is related to elevation of intracellular calcium during CPB and propofol has a protective effect on erythrocyte injury.
 ...
PMID:The protective effect of propofol on erythrocytes during cardiopulmonary bypass. 1531 80