Changes in Na(+)/K(+)-ATPase activity and abundance associated with environmental salinity were investigated in the gills and rectal gland of the Atlantic stingray Dasyatis sabina. Using a ouabain-specific ATPase assay and western blotting, we found that stingrays from fresh water had the highest activity and highest relative abundance of Na(+)/K(+)-ATPase in the gills. Using immunohistochemist...

In the gills of freshwater teleost fishes, vacuolar proton-ATPase (V-H(+)-ATPase) is found on the apical membrane of pavement and chloride (Na(+)/K(+)-ATPase-rich) cells, and is an important transporter for energizing Na(+) uptake and H(+) excretion. In the gills of elasmobranch fishes, the V-H(+)-ATPase has not been extensively studied and its expression in freshwater individuals has not been ...

This study compares salinity tolerance between red and black shell Pinctada fucata stress of 20 50‰, while 35‰ was used as a control. The hemolymph osmotic pressure, inorganic ion concentration, the activities Na + -K -ATPase, respiratory metabolism related enzymes liver tissue antioxidant were measured at 12 24 h after stress. pressure concentration two strains P. increased significantly with ...

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...