Intestinal transport of potassium. Effects of changing apical and basolateral influx of sodium in the isolated mucosa of the hen (Gallus domesticus) colon.
1. Net potassium secretion (JKnet) by the sodium-depleted hen's colon (low sodium colon) is 0.17 +/- 0.07 mumol/cm2.hr. Amiloride or ouabain eliminates short circuit currents (Isc) of 16-20 mumol/cm2.hr without affecting JKsm. 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 JKnet from 0.08 +/- 0.04 to (a) 0.42 +/- 0.07, to (b) 0.60 +/- 0.07 to (c) 0.13 +/- 0.13 mumol/cm2.hr. 3. In both colonic types theophylline increases and bumetanide decreases JKnet by 1 mumol/cm2.hr. 4.


CONCLUSIONS
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 potassium-impermeable apical membranes.
Munck
L K
LK
Bispebjerg Hospital, Department of Internal Medicine P, Copenhagen, Denmark.
Munck
B G
BG
D000818:Animals; D001692:Biological Transport / Q000502:physiology; D002645:Chickens / Q000378:metabolism*; D003106:Colon / Q000378:metabolism; D005260:Female; D066298:In Vitro Techniques; D007413:Intestinal Mucosa / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism*
D012964:Sodium; D011188:Potassium