Abstract
1. 1. Net potassium secretion (Jnet K) by the sodium-depleted hen's colon (low sodium colon) is 0.17 ± 0.07 μmol/cm2·hr Amiloride or ouabain eliminates short circuit currents (Isc) of 16-20 μmol/cm2· hr without affecting Jsm K. 2. 2. In the NaCl-loaded hen's colon (high sodium colon) stimulating Isc by (a) glucose, (b) amino acids, and inhibiting with (c) ouabain changes Jnet K from 0.08 ± 0.04 to (a) 0.42 ± 0.07, to (b) 0.60 ± 0.07 to (c) 0.13 ± 0.13 μmol/cm2·hr. 3. 3. In both colonie types theophylline increases and bumetanide decreases Jnet K by 1 μmol/cm2·hr. 4. 4. Conclusion: Apical membranes of sodium-absorbing and chloride-secreting cells of the high sodium colon are potassium permeable. In the low sodium colon sodium-absorbing cells have potassiumimpermeable apical membranes.
Originalsprog | Engelsk |
---|---|
Sider (fra-til) | 181-186 |
Antal sider | 6 |
Tidsskrift | Comparative Biochemistry and Physiology -- Part A: Physiology |
Vol/bind | 96 |
Udgave nummer | 1 |
DOI | |
Status | Udgivet - 1990 |