Bladzijde 1 van 23 resultaten
The transepithelial voltage (Vte) and the volume of isolated posterior midguts of adult female yellow fever mosquitoes (Aedes aegypti) were monitored. In all experiments, the initial Vte after filling the midgut was lumen negative, but subsequently became lumen positive at a rate of approximately 1
The effect of hyperthermia in the 41-50 degrees C range on the Na+,K+-ATPase of CHO cells has been investigated. Three separate activities of the enzyme, namely, ATP hydrolysis, K+ uptake, and binding of the specific inhibitor, ouabain, have been measured independently. The results can be summarized
The effects of hyperthermia (41-43 degrees C) on the membrane potential (calculated from the transmembrane distribution of [3H]tetraphenylphosphonium) and Na+ transport of Chinese hamster V79 fibroblasts were studied. At 41 degrees C, hyperthermia induced a membrane hyperpolarization of log phase
Recently, Na(+)/K(+)-ATPase has been detected in the luminal membrane of the anterior midgut of larval yellow fever mosquitoes (Aedes aegypti) with immunohistochemical techniques. In this study, the possible involvement of this ATPase in strong alkalinization was investigated on the level of whole
The purpose of this study was to determine the concentration of Ca(2+)-ATPase and Na(+)-K(+)-ATPase in biopsies from vastus lateralis muscle of 24 patients, who underwent a diagnostic contracture test for susceptibility to malignant hyperthermia (MH). Ca(2+)-ATPase was quantified as the
The effect of water-bath hyperthermia on rabbit peritoneal macrophages was studied in vitro. The cells were exposed to hyperthermia for 30 min to 4 hours and membrane transport of ions as measured by total and ouabain-inhibited 86Rb influx as well as membrane permeability for 86Rb and 51Cr-labelled
The ouabain-sensitive ATP-hydrolysing activity, representing the Na+/K+ ATPase capacity, of isolated membranes and whole cells during and after hyperthermia treatments was investigated. In isolated membranes no heat damage after treatments up to 46 degrees C during 45 min or up to 6 h at 44 degrees
Clinical experience and experimental studies have shown that hyperthermia can cause cerebral ischaemia and brain damage. By in vitro experiments with heating, we previously were able to induce carotid artery constriction. The objective of the present study was to clarify the mechanism of this
Transverse tubule (TT) membrane vesicles have been isolated from the skeletal muscle of normal and malignant hyperthermia-susceptible (MHS) pigs. MHS and normal TT did not differ in the distribution of the major proteins, cholesterol, or phospholipid content, (Na+ + K+)-ATPase activity, [3H]ouabain
Sarcolemmal properties implicated in the skeletal muscle disorder, malignant hyperthermia (MH), were examined using sarcolemma-membrane vesicles isolated from normal and MH-susceptible (MHS) porcine skeletal muscle. MHS and normal sarcolemma did not differ in the distribution of the major proteins,
EMT6 multicellular spheroids invariably swell by 10 to 50 per cent after incubation at 43 to 45 degrees C for 1 h. Both scanning electron and optical microscopy reveal morphological alterations particularly in the outer region of the spheroids. While the control cells are contiguous to one another
The effect of hyperthermia on the Na+-K+ pump was determined by measuring influx and efflux of 86Rb+ in Chinese hamster ovary cells from 31 to 50 degrees C. The maximum initial rate of ouabain-sensitive influx increased with temperature between 31 and 45 degrees C although Km increased significantly
When HeLa cells are exposed to brief heat shock at 45 degrees C there is a reduction in the cellular level of Na+K+ATPase. Return of the cells to the normal growth temperature of 37 degrees C leads to a partial restoration of enzyme activity. The pattern of this recovery of activity suggests that it
The metabolic reactions responsible for the release of endogenous pyrogen from rabbit granulocytes incubated in 0.15 M NaCl are specifically inhibited by the presence of K(+) (and by related alkali metal ions, Rb(+) and Cs(+)) in the medium. The inhibitory action of K(+) apparently involves