1. Sodium influx was measured in isolated, previously perfused gill arches of rainbow trout, Salmo gairdneri, by measuring incorporation of 22Na into gill tissue following timed exposure to a 1 mM 22NaCl medium. Transport rates approximated those estimated for intact fish and were linear for at least one min. 2. NH4Cl-containing perfusates at pH 7 and 8 stimulated Na+ influx equally, indicating that only ionized ammonia is important in the transport process. A Na+/NH4+ exchange at basal and/or lateral membranes of the transporting cells is suggested. 3. Low-sodium Ringer perfusate augmented Na+ influx; in one group of gills the transport rate was more than double that of NaCl Ringer controls. The increase in transport induced by internal NH4+ was not additive with the low sodium augmentation. A reduction in intracellular (Na+) is postulated as the mechanism operating in both cases. 4. Ouabain had no appreciable effect on Na+ influx, either with or without NH4+ in the perfusate. Diamox partially blocked the augmented Na+ influx induced by NH4+. Amiloride completely inhibited Na+ influx, both with and without NH4+ in the perfusate.
Skip Nav Destination
JOURNAL ARTICLE| 01 April 1976
On the interaction of NH+4 and Na+ fluxes in the isolated trout gill
T. H. Kerstetter
Online Issn: 1477-9145
Print Issn: 0022-0949
© 1976 by Company of Biologists
J Exp Biol (1976) 64 (2): 517–527.
- Views Icon Views
- PDF LinkPDF
- Share Icon Share
- Search Site
T. H. Kerstetter, M. Keeler; On the interaction of NH+4 and Na+ fluxes in the isolated trout gill. J Exp Biol 1 April 1976; 64 (2): 517–527. doi: https://doi.org/10.1242/jeb.64.2.517
Download citation file: