+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

Ammonium ion substitutes for potassium in atp dependent sodium transport by basolateral membrane vesicles

, : Ammonium ion substitutes for potassium in atp dependent sodium transport by basolateral membrane vesicles. American Journal of Physiology 252(3 PART 2): R479-R489

Ion-transporting cells from posterior gills of blue crabs (Callinectes sapidus) acclimated to low salinity were used as starling material for the preparation of microsomal membrane vesicles by density gradient centrifugation. The Na+-K+-adenosinetriphosphatase (ATPase)-enriched basolateral vesicles were loaded with KCl- or .**GRAPHIC**. -containing medium by dilution and centrifugation, and initial rates of 22Na+ uptake into the vesicles were measured by a rapid filtration procedure. Varying the extravesicular sucrose concentration altered equilibrium uptake of 22Na+, indicating the existence of osmotically sensitive vesicles. Monensin, a sodium-specific ionophore, enhanced passive uptake of 22Na+ across the vesicle membrane in the absence of ATP. With 100 mM KCl in the intravesicular medium, addition of ATP to the extravesicular medium increased initial rates of 22Na+ uptake 10- to 20-fold over levels measured without ATP. A nonhydrolyzable ATP analog failed to stimulate 22Na+ uptake. Intravesicular K+ could be replaced by .**GRAPHIC**. but not by choline. With .**GRAPHIC**. as counteriorn, NA+ transport was inhibited by digitoxin, but valinomycin had no effect. A study of the kinetic effects of intravesicular K+ and .**GRAPHIC**. on initial rates of 22Na+ uptake indicated the existence of two classes of binding sites, one responding to counterion concentrations in the millimolar range and a second class responding to counterion concentrations over 50 mM. Our results indicate that ATP-dependent 22Na+ uptake by membrane vesicles from Callinectes sapidus gill, mediated by Na+-K+-ATPase, can utilize either K+ or .**GRAPHIC**. as counterion.


Other references

Kieffer, V.; Oppenheim, D.; Laroussime, F.; Gadalou, G.; Coutinho, V.; Ribaille, C.; Raquin, M. , A.; Doz, F.; Hartmann, O.; Kalifa, C.; Laurent-Vannier, A.; Grill, J., 2007: Une consultation multidisciplinaire pour les enfants traites pour une tumeur cerebrale. School achievement of children with brain tumors is hampered by progressive neurologic and cognitive sequelae. To help the children and their family, we have created in 1997 a multidisciplinary consultation together with Necker's hospital.Mat...

Chernashov, I.M.; Lemeshev, A.P., 1978: Rare source of hemorrhage in liver cirrhosis. Vestnik Khirurgii Imeni I. I. Grekova 121(7): 55-55

Carlsson, L., 1979: Gulls klepto-parasitizing heron, Ardea cinerea. Var Fagelvarld, 381: 50

Yang, A-Lun.; Lee, S-Da.; Su, C-Ting.; Wang, J-Long.; Lin, K-Long., 2007: Effects of exercise intervention on patients with stroke with prior coronary artery disease: aerobic capacity, functional ability, and lipid profile: a pilot study. Objective: To assess the effects of exercise intervention on aerobic capacity, functional ability and lipid profile in patients after stroke with prior coronary artery disease. Patients: Fifteen patients after stroke with prior coronary artery di...

Sinclair, J.F.; Szakacs, J.G.; Wood, S.G.; Kostrubsky, V.E.; Jeffery, E.H.; Wrighton, S.A.; Bement, W.J.; Wright, D.; Sinclair, P.R., 2000: Acetaminophen hepatotoxicity precipitated by short-term treatment of rats with ethanol and isopentanol: Protection by triacetyloleandomycin. Ethanol and isopentanol are the predominant alcohols in alcoholic beverages. We have reported previously that pretreatment of rats with a liquid diet containing 6.3% ethanol plus 0.5% isopentanol for 7 days results in a synergistic increase in ace...

Manschot, W.A., 1969: Ophthalmic pathological findings in a case of thallium poisoning. Ophthalmologica. Journal International D'ophtalmologie. International Journal of Ophthalmology. Zeitschrift für Augenheilkunde 158 Suppl: 348-349

Saleem, A.; Harris, C.S.; Asim, M.; Cuerrier, A.; Martineau, L.; Haddad, P.S.; Arnason, J.T., 2010: A RP-HPLC-DAD-APCI/MSD method for the characterisation of medicinal Ericaceae used by the Eeyou Istchee Cree First Nations. Ericaceae medicinal plants are traditionally used by the Eeyou Istchee Cree and other northern peoples of North America to treat type 2 diabetic symptoms. Because of the importance of phenolics as potential cures for degenerative diseases includin...

E.I.K.likina; R.I.K.yukova; M.G.G.ndman; I.V.K.irich; A.N.K.tashova, 1973: Experiment in the use of an enzymatic hydrolysate of starch for streptomycin biosynthesis. Pharmaceutical Chemistry Journal 7(3): 159-160

Kukuljan, M.; Stojilković, S.S.; Rojas, E.; Catt, K.J., 1992: Apamin-sensitive potassium channels mediate agonist-induced oscillations of membrane potential in pituitary gonadotrophs. In cultured rat pituitary gonadotrophs, gonadotropin-releasing hormone (GnRH) induces rapid hyperpolarization of the cell membrane and causes cessation of the spontaneous electrical activity present in non-stimulated cells. This initial response t...

Twery M.J.; Feicht D.L.; Fosbroke S.L.C., 1992: Understory development following thinning and defoliation in west virginia. Bulletin of the Ecological Society of America 73(2 SUPPL): 370