Search results for "Calcium ATPase"
showing 6 items of 6 documents
A new method for the in situ determination of phospholipids after thin-layer separation
1973
Abstract A very sensitive method has been devised for the in situ determination of phospholipids after thin-layer chromatographic separation, which enabled us to investigate the phospholipid content of erythrocytes and ATPase preparations. The phospholipid compositions of the ATPase preparations and of the erythrocytes are different, and the relative phospholipid compositions of the Na,K-ATPase preparations are also different, which indicates that Na,K- and Ca-ATPase seem to be different with regard to their phospholipid composition. An increase in temperature during the preparation procedure yields a Ca-ATPase preparation (II), which exhibits different kinetic properties and a different ph…
Histochemical localization of calcium ATPase in the cochlea of the guinea pig
1992
The activity of Ca(2+)-ATPase in the inner ear of the guinea pig was studied ultracytochemically by the lead citrate reaction. The electron-dense reaction products as an expression of Ca(2+)-ATPase activity were localized in endolymphatic cells of Reissner's membrane, in outer and inner hair cells and in some supporting cells. The main finding was the difference in the localization of Ca(2+)-ATPase in outer and inner hair cells. In the latter cells the activity sites were mainly intracellular and in apical membrane specializations, whereas in the outer hair cells the enzyme was localized in the apical membrane specializations and the basolateral plasma membrane.
When tubules aggregate
2011
Within muscle fibres, tubules appear as microtubules, transverse tubules, and different components of the sarcotubular system, the latter consisting of longitudinal tubules and lateral or terminal sacs which, at special junctional connections, are situated on both sides of transverse tubules forming triads. Pathological structures related to the transverse tubules are honeycomb structures, both the transverse tubules and the honeycomb ones being labelled by extracellularly applied lanthanum [1] or potassium ferrocyanide [2], thus, indicating an open connection between the interior of the muscle fibres and the extracellular space. Dyads or multiple incomplete or complete forms of triads, pen…
Glucose-induced alterations of cytosolic free calcium in cultured rat tail artery vascular smooth muscle cells
1995
We have previously suggested that hyperglycemia per se may contribute to diabetic hypertensive and vascular disease by altering cellular ion content. To more directly investigate the potential role of glucose in this process, we measured cytosolic free calcium in primary cultures of vascular smooth muscle cells isolated from Sprague-Dawley rat tail artery before and after incubation with 5 (basal), 10, 15, and 20 mM glucose. Glucose significantly elevated cytosolic free calcium in a dose- and time-dependent manner, from 110.0 +/- 5.4 to 124.5 +/- 9.0, 192.7 +/- 20.4, and 228.4 +/- 21.9 nM at 5, 10, 15, and 20 mM glucose concentrations, respectively. This glucose-induced cytosolic free calci…
Plasma membrane Ca2+ ATPase 4 is required for sperm motility and male fertility.
2004
Calcium and Ca(2+)-dependent signals play a crucial role in sperm motility and mammalian fertilization, but the molecules and mechanisms underlying these Ca(2+)-dependent pathways are incompletely understood. Here we show that homozygous male mice with a targeted gene deletion of isoform 4 of the plasma membrane calcium/calmodulin-dependent calcium ATPase (PMCA), which is highly enriched in the sperm tail, are infertile due to severely impaired sperm motility. Furthermore, the PMCA inhibitor 5-(and-6)-carboxyeosin diacetate succinimidyl ester reduced sperm motility in wild-type animals, thus mimicking the effects of PMCA4 deficiency on sperm motility and supporting the hypothesis of a pivot…
Ultracytochemical localization of Ca2(+)-ATPase activity in the middle ear mucosa of the guinea pig.
1989
Ca2(+)-ATPase activity was studied ultra-cytochemically in the middle ear mucosa of the guinea pig. On electron microscopic examination, the most intense reaction was found on the microvilli. Reaction products were also observed on the cilia and around and between the secretory granules on the apical side of the cells in their secretory phase. The basolateral membranes contained few reaction products, while very little or no activity was found on the basal membrane.