... in the gills. To further characterize the role of Pt Rh in ammonia metabolism and excretion, double-stranded RNA-mediated RNA interference of Pt Rh was employed. Knockdown of Pt Rh upregulated mRNA expression of ammonia excretion-related genes encoding aquaporin (AQP), K + channels and vesicle-associated...

...Dirk Weihrauch; Garett J. P. Allen ABSTRACT Invertebrates employ a variety of ammonia excretion strategies to facilitate their survival in diverse aquatic environments, including freshwater, seawater and the water film surrounding soil particles. Various environmental properties set innate...

... active Na + uptake are quite well understood in freshwater teleosts; however, the mechanisms employed by invertebrates are not. Pharmacological and molecular approaches were used to investigate Na + uptake mechanisms and their link to ammonia excretion in the ribbon leech Nephelopsis obscura...

..., across biological membranes. Zebrafish embryos were microinjected with a translation-blocking morpholino oligonucleotide targeted to AQP1a1. Knockdown of AQP1a1 significantly reduced rates of CO 2 and ammonia excretion, as well as water fluxes, in larvae at 4 days post fertilization (dpf). Because AQP1a1...

... metabolic rate (RMR) in FT phenotypes when fasting, and (2) tolerance reflects differences in substrate utilisation; FT phenotypes use relatively less proteins as metabolic fuels during fasting, measured as their ammonia quotient (AQ), the simultaneous ratio of ammonia excretion to RMR...

...C. Y. C. Hung; K. N. T. Tsui; J. M. Wilson; C. M. Nawata; C. M. Wood; P. A. Wright SUMMARY The mechanism(s) of ammonia excretion in the presence of elevated external ammonia are not well understood in fish. Recent studies in other organisms have revealed a new class of ammonia transporters, Rhesus...

... for correspondence e-mail: [email protected] 25 4 2006 © The Company of Biologists Limited 2006 2006 nitrogen excretion ammonia excretion oxygen consumption serotonin 5-HT ketanserin cortisol RU-486 killifish Rivulus marmoratus The rate of nitrogenous waste excretion...

... of the hypothesis that the rhythm amplitude differs from zero. Furthermore, comparisons of the maximal absolute urea and ammonia excretion values between experimental series were performed using t -tests with either assumptions for equal or unequal variances ( P <0.05).Verification of equal variances...

... site of NH 3 volatilization. * Author for correspondence (e-mail: [email protected] ) 7 3 2006 © The Company of Biologists Limited 2006 2006 NH 3 volatilization nitrogen excretion ammonia excretion water pH fish skin boundary layer amphibious fish Rivulus marmoratus...

...Dirk Weihrauch; Steve Morris; David W. Towle SUMMARY The excretory transport of toxic ammonia across epithelia is not fully understood. This review presents data combined with models of ammonia excretion derived from studies on decapod crabs, with a view to providing new impetus to investigation...

... ). Alkaline environmental pH has no effect on the excretion of ammonia in the mudskipper Periophthalmodon schlosseri but inhibits ammonia excretion in the related species Boleophthalmus boddaerti . Physiol. Biochem. Zool. 76 , 204 -214. Chew, S. F., Wilson, J. M., Ip, Y. K. and Randall, D. J. ( 2004...

... © The Company of Biologists Limited 2004 2004 aestivation Protopterus dolloi lungfish nitrogen metabolism ammonia excretion urea excretion mucus cocoon Lungfishes (or dipnoans, as they are `dual breathers') are an archaic group of fishes, characterized by the possession...

... gradient across the branchial and body surfaces and would reduce the net influx of NH 3 during ammonia loading. * Author for correspondence (e-mail: [email protected] ) 15 7 2003 © The Company of Biologists Limited 2003 2003 ammonia ammonia detoxification ammonia excretion...

... mechanism in the gill of the toadfish. * Author for correspondence (e-mail: [email protected] ) 21 1 2003 © The Company of Biologists Limited 2003 2003 glutamine synthetase toadfish ureotely ornithine–urea cycle ammonia detoxification Opsanus beta ammonia excretion...

... by DPC (10 -4 mol l -1 ) and thiocyanate (10 -4 mol l -1 ). Ammonia excretion was unresponsive to large changes in water Na + concentration, but was elevated by 70% during acute exposure to pH 4.0 and transiently inhibited by approximately 50% by amiloride and its analogues. The strategy of adaptation...

...Dirk Weihrauch; Andreas Ziegler; Dietrich Siebers; David W. Towle SUMMARY Although aquatic animals are generally believed to export nitrogenous waste by diffusion of NH 3 or NH 4 + across external epithelia, evidence for active ammonia excretion has been found in a number of species...

..., oxygen consumption and ammonia excretion rates increased approximately twofold following exhaustive exercise. Post-exercise oxygen consumption rates decreased to control levels within 30 min in both sturgeon species, but post-exercise ammonia excretion rates remained high in Atlantic sturgeon throughout...

...Annika Salama; Ian J. Morgan; Chris M. Wood ABSTRACT The nature of the linkage between between branchial ammonia excretion ( J Amm ) and unidirectional Na + influx was studied in the freshwater rainbow trout ( Oncorhynchus mykiss ). Arterial plasma total [ammonia], P NH and J Amm were all elevated...

...-bremerhaven.de † Present address: Institut für Tierphysiologie, Freie Universität Berlin, Grunewaldstrasse 34, D-12165, Berlin, Germany 9 10 1997 9 12 1997 © The Company of Biologists Limited 1988 acid–base regulation ammonia excretion buffer value CO2 partial pressure...

...E. Rahaman-Noronha; M. J. O’Donnell; C. M. Pilley; P. A. Wright ABSTRACT This study examined ammonia excretion by embryos of the rainbow trout ( Oncorhynchus mykiss ). The distribution of ammonia in relation to the H + distribution and electrical potential was determined. The influence of the pH...