dc.creator | SILVA, E. C. C. | |
dc.creator | MASUI, D. C. | |
dc.creator | FURRIEL, R. P. M. | |
dc.creator | MANTELATTO, F. L. M. | |
dc.creator | MCNAMARA, J. C. | |
dc.creator | BARRABIN, H. | |
dc.creator | LEONE, F. A. | |
dc.creator | SCOFANO, H. M. | |
dc.creator | FONTES, C. F. L. | |
dc.date.accessioned | 2012-10-19T14:14:34Z | |
dc.date.accessioned | 2018-07-04T15:01:30Z | |
dc.date.available | 2012-10-19T14:14:34Z | |
dc.date.available | 2018-07-04T15:01:30Z | |
dc.date.created | 2012-10-19T14:14:34Z | |
dc.date.issued | 2008 | |
dc.identifier | COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY B-BIOCHEMISTRY & MOLECULAR BIOLOGY, v.149, n.4, p.622-629, 2008 | |
dc.identifier | 1096-4959 | |
dc.identifier | http://producao.usp.br/handle/BDPI/20765 | |
dc.identifier | 10.1016/j.cbpb.2007.12.010 | |
dc.identifier | http://dx.doi.org/10.1016/j.cbpb.2007.12.010 | |
dc.identifier.uri | http://repositorioslatinoamericanos.uchile.cl/handle/2250/1617544 | |
dc.description.abstract | Euryhaline crustaceans rarely hyporegulates and employ the driving force of the Na,K-ATPase, located at the basal surface of the gill epithelium, to maintain their hemolymph osmolality within a range compatible with cell function during hyper-regulation. Since polyamine levels increase during the adaptation of crustaceans to hyperosmotic media, we investigate the effect of exogenous polyamines on Na,K-ATPase activity in the posterior gills of Callinectes danae, a euryhaline swimming crab. Polyamine inhibition was dependent on cation concentration, charge and size in the following order: spermine > spermidine > putrescine. Spermidine affected K-0.5 values for Na+ with minor alterations in K-0.5 values for K+ and N-H-4(+), causing a decrease in maximal velocities under saturating Na+, K+ and NH4+ concentrations. Phosphorylation measurements in the presence of 20 mu M ATP revealed that the Na,K-ATPase possesses a high affinity site for this substrate. In the presence of 10 mM Na+, both spermidine and spermine inhibited formation of the phosphoenzyme; however, in the presence of 100 mM Na+, the addition of these polyamines allowed accumulation of the phosphoenzyme. The polyamines inhibited pumping activity, both by competing with Na+ at the Na+-binding site, and by inhibiting enzyme dephosphorylation. These findings suggest that polyamine-induced inhibition of Na,K-ATPase activity may be physiologically relevant during migration to fully marine environments. (c) 2008 Elsevier Inc. All rights reserved. | |
dc.language | eng | |
dc.publisher | ELSEVIER SCIENCE INC | |
dc.relation | Comparative Biochemistry and Physiology B-biochemistry & Molecular Biology | |
dc.rights | Copyright ELSEVIER SCIENCE INC | |
dc.rights | restrictedAccess | |
dc.subject | Na,K-ATPase | |
dc.subject | polyamines | |
dc.subject | gill microsomes | |
dc.subject | Callinectes danae | |
dc.subject | euryhaline swimming crab | |
dc.title | Regulation by the exogenous polyamine spermidine of Na,K-ATPase activity from the gills of the euryhaline swimming crab Callinectes danae (Brachyura, Portunidae) | |
dc.type | Artículos de revistas | |