On the Mechanism of Sodium Extrusion across the Irrigated Gill of Sea Water - Adapted Rainbow
نویسندگان
چکیده
Sodium efflux (JNut) across the irrigated trout gill was rapid in sea water (SW), but only about 25 % as large in fresh water (FW). The difference correlated with a change in the potential difference across the gill (TEP). The latter was about +10 mV (blood positive) in SW, but -40 mV in FW. Both flux and electrical data indicated that gills in this fish are permeable to a variety of cations including Na+, K+, Mg2+, choline, and Tris. They are less permeable to anions; PNa:PK:Pcl was estimated to be 1:10:0.3, and Pc > Po,,,ot,. The TEP was shown to be a diffusion potential determined by these permeabilities and the extant ionic gradients in SW, FW as well as in other media. JoNt appeared to be diffusive in all of the experiments undertaken. Exchange diffusion need not be posited, and the question of whether there is an active component remains open.
منابع مشابه
Sodium Efflux and Potential Differences across the Irrigated Gill of Sea Water-Adapted Rainbow Trout (Salmo gairdneri)
Sodium extrusion (J(out) (Na)) was measured across the gills of rainbow trout, Salmo gairdneri, adapted to sea water (SW) using a gill-irrigation system of small volume. The potential difference (TEP) was also measured under similar conditions. J(out) (Na) was usually between 100-250 microeq (100 g)(-1) h(-1), about an order of magnitude faster than in fresh water (FW)-adapted trout, but slower...
متن کاملOn the Mechanism of Sodium Extrusion across the Irrigated Gill of Sea Water - Adapted Rainbow Trout
Sodium efflux (JNut) across the irrigated trout gill was rapid in sea water (SW), but only about 25 % as large in fresh water (FW). The difference correlated with a change in the potential difference across the gill (TEP). The latter was about +10 mV (blood positive) in SW, but -40 mV in FW. Both flux and electrical data indicated that gills in this fish are permeable to a variety of cations in...
متن کاملOn the Mechanism of Sodium Extrusion across the Irrigated Gill of Sea Water-Adapted Rainbow Trout (Salmo gairdneri)
Sodium efflux (J(out) (Na)) across the irrigated trout gill was rapid in sea water (SW), but only about 25 % as large in fresh water (FW). The difference correlated with a change in the potential difference across the gill (TEP). The latter was about +10 mV (blood positive) in SW, but -40 mV in FW. Both flux and electrical data indicated that gills in this fish are permeable to a variety of cat...
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