... volume increase amiloride hyperosmotic stress The Root effect, a phenomenon limited almost exclusively to teleost fishes, is defined as the decrease in O 2 carrying capacity of the blood due to a decrease in pH ( Brittain, 1987 ; Ingermann, 1982 ; Pelster and Weber, 1991 ; Root, 1931...

... in supplying acid–base equivalents to the respective transporters. Furthermore, any apical processes proposed to be involved in alkali secretion or acid absorption must be Cl – independent and insensitive to DIDS,amiloride, Zn 2+ and ouabain. These results argue against the involvement of putative apical Cl...

... (100 μmol l –1 phenamil), 21-fold (10 μmol l –1 CDPC) or 12-fold (2 mmol l –1 amiloride) when Cu o was 800 μmol l –1 compared to those in drug-free controls. Lowering the external chloride concentration [Cl – ] o from 131.6 to 6.6 mmol l –1 (replaced by sodium gluconate) caused the rate of Cu...

... to almost complete blockage of active and gradient-driven ammonia excretion. Actin filaments seem not to play a role in the excretory process. The NH 4 + -dependent short-circuit current and the conductance of the isolated cuticle were reduced in a dose-dependent manner by amiloride,a non-specific inhibitor...

... to 4.6±0.54 μA cm -2 in preparations adapted to high salinity. The involvement of epithelial Na + channels was determined as current inhibition ( I ami ) by apical application of amiloride; Na + channels were equally active in control epithelia and epithelia from leeches adapted to high salinity. Removal...

... at a conductance ( G te ) of 40±2 mS cm –2 . The net influxes of Na + and Cl – were 8.3±2.6 and 18.2±2.7 μmol cm –2 h –1 , respectively. External amiloride (100 μmol l –1 ) reduced G te to approximately 50 % of the original value at unchanged I sc ; Cl – fluxes remained unaffected, whereas Na + fluxes were...

... integument, none of them mimicked the effect of an experimental rise in intracellular cyclic AMP level. The invertebrate peptides conopressin and angiotensin II amide inhibited short-circuit-current-( I sc ) and amiloride-sensitive Na + transport ( I amil ), although to slightly different degrees...

... by the blockade of either Na + /H + exchange (using amiloride) or anion transport (using DIDS). The removal of external HCO 3 − and the abolition of outward K + diffusion by the channel blocker Ba 2+ also decreased the rate of proton extrusion following acid load. Depolarization of the cell membrane with 50 mmol...

... , an inhibitor of the H+-ATPase, or with amiloride, an inhibitor of the H + /K + antiporter. However, the antidiuretic-factor-stimulated fluid reabsorption is not affected by either bafilomycin A 1 or amiloride. The increase in reabsorption triggered by the semi-purified factor can be inhibited by Cl − channel...

... and to a three-to fourfold increase in Na + influx. The RVI and the activated Na + influx were blocked by the transport inhibitors amiloride and 4,4′-diisothiocyanatostilbene-2,2′-disulphonic acid (DIDS), both at a concentration of 10 −4 mol l −1 , and the RVI was abolished in a Na + -free saline, indicating...

...Thomas Cox ABSTRACT The skin of the bullfrog Rana catesbeiana tadpole contains an apical non-selective cation channel that is activated by amiloride. This is in contrast to the adult skin, which has a highly Na + -selective channel that is blocked by amiloride. The purpose of the present study...

... O 7 .10H 2 O), 2.5 mmol l −1 Hepes, 0.1 mmol l −1 amiloride] for 30 min and ammonia excretion rates, ammonia concentration in the perivitelline fluid (PVF) and yolk, and the pH of the PVF, yolk and USL were measured. The rate of ammonia excretion was dependent, in part, on the partial pressure...

... of these vesicles were 15.4-and 1.2-fold, respectively. The presence of amiloride-sensitive Na + /H + exchange was demonstrated. Contrary to electrogenic 2Na + /1H + exchange on apical membranes from the same tissue, kinetic studies of Na + transport by these basolateral membranes indicate an electroneutral...

... of an induced membrane potential (inside negative; K + /valinomycin). External amiloride (competitive inhibitor; K i =660 μ mol l −1 ) and a monoclonal antibody raised against proteins associated with the lobster ( Homarus americanus ) electrogenic 2Na + /1H + antiporter both inhibited approximately half...

... + -pumping V-ATPase, driving secretion of Na + or K + through one or more exchangers, at least one of which is amiloride-sensitive and appears to be closely similar to the Na + /H + exchanger of vertebrates ( Maddrell and O’Donnell, 1992 ). Cl − follows passively, perhaps through apical Cl − channels. Water...

... gland coelomosac podocytes and posterior gill epithelial cells – all locations where published reports described unique cation exchange kinetics. Significant fractions of Ca 2+ transport into invertebrate cells across brush-border membranes occurred by an electrogenic, amiloride-sensitive exchange...

.... 23 6 1993 © 1993 by Company of Biologists 1993 amiloride toad hydration behavior Bufo punctatus The experiments described here were designed to determine whether the receptors present in amphibian skin are specific to particular solutes, i.e. can toads taste with their skin...

... of this experimental approach and an improved technique enabled us to observe pHi regulation even in Cl − -free saline, in contrast to earlier findings. In addition, amiloride (2mmol l − 1) inhibited the maximum rate of pHi recovery by about 80%, SITS (1mmol l − 1) by about 20%. The results strongly suggest...

.... ( 1989 ). A reappraisal of the oil-gap technique for the measurement of transtubular potentials in insect epithelia . J. exp. Biol . 141 , 429 – 440 . Kleyman , T. R. and Cragoe , E. J. ( 1988 ). Amiloride and its analogs as tools in the study of iontransport . J. Membr. Biol...

...Hong Lin; David Randall ABSTRACT Ion transport inhibitors, amiloride, SITS, vanadate and acetazolamide, were added to the water to determine the effect of ion transfer mechanisms on the acidification of water passing over the gills. In neutral water, proton excretion causes a marked reduction...