This article offers an explanation for the apparent lack of Na, K-ATPase activity in parietal cells although ouabain has been known to inhibit gastric acid secretion since 1962. The gastric H, K-ATPase (proton-pump) seems to be acting in altered states, thus behaving like a Na, K-ATPase (Na-pump) and/or Ca-ATPase (Ca-pump) depending on cellular needs.  This conclusion is based on the following ...

Small tension signals that pass between the two linked heads of kinesin allow the motor protein to coordinate its walking action. Two new studies suggest that certain members of the two other major families of motor proteins, the myosins and dyneins, can do the same thing.

F1-ATPase is the catalytic component of the ATP synthase molecular machine responsible for most of the uphill synthesis of ATP in living systems. The enormous advances in biochemical and structural studies of this machine provide an opportunity for detailed understanding of the nature of its rotary mechanism. However, further quantitative progress in this direction requires development of relia...

this study investigated the cytochemical responses in hediste diversicolor exposed to the environmental concentrations of cadmium (1µm cd), copper (1µm cu) and to their equimolar mixture for 48h. lysosomal membrane stability (lms), neutral lipids (nl) level, lipofuscin (lf) content and ca2+-atpase activity were determined as early subcellular biomarkers of toxicity. the biomarker battery pointe...

the effect of annona squamosa, lawsonia inermis and their combination with other herbal molluscicides were studied on different enzyme activity in the nervous tissue of lymnaea acuminata. twenty-four hour in vivo exposure to 40% and 80% of 24 h lc50 of plant derived molluscicides and their combination with other molluscicides such as cedrus deodara, azadirachta indica oil, allium sativum, polia...

Vesicular V-ATPase (V-type H+-ATPase) and the plasma membrane-bound Na+/K+-ATPase are essential for the cycling of neurotransmitters at the synapse, but direct functional studies on their action in native surroundings are limited due to the poor accessibility via standard electrophysiological equipment. We performed SSM (solid supported membrane)-based electrophysiological analyses of synaptic ...

Because of their diverse habitats, crabs are excellent experimental species to study owing to the morphological changes and physiological adaptation that occur during their terrestrial invasion. Their hemolymphic osmoregulation in brackish water is crucial for a successful terrestrial invasion. Crabs can actively uptake or excrete ions upon salinity change, and the gills play a major role among...

Since defective regulation of ion transport could initiate or contribute to the abnormal cellular function in myotonic dystrophy (MyD), Na+/K(+)-ATPase and sarcoplasmic reticulum (SR) Ca(2+)-ATPase were examined in skeletal muscle and cultured skeletal muscle cells of controls and MyD patients. Na+/K(+)-ATPase was investigated by measuring ouabain binding and the activities of Na+/K(+)-ATPase a...

One of the cell-adhesion molecules (CAMs) responsible for rat hepatocyte aggregation has been described as a glycoprotein having an Mr of 105,000 (cell-CAM105). The Mr and localization of cell-CAM105 in liver membranes are very similar to those of liver ecto-ATPase, an ATPase with its nucleotide-hydrolysing site localized on the outside of the cell membrane. The protein sequence of the ecto-ATP...