Effects of anisosmotic buffers on K+ transport in isolated chicken enterocytes.
Cells isolated by hyaluronidase incubation from chicken small intestine were used to study the effects of anisosmotic buffers on K+ transport. Hypo-osmolarity (200 mosmol.l-1) reduced both the ouabain-sensitive and the ouabain-resistant, but bumetanide-sensitive, net K+ influx and increased the K+ efflux. The hypo-osmolarity induced K+ efflux was prevented by quinine and unaffected by bumetanide. These results suggest that Ca2+-activated K+ channels may be involved in regulatory volume decrease in chicken enterocytes. Hyperosmotic conditions (400 mosmol.l-1) increased the portion of net K+ influx mediated by the Na+/K+-ATPase and that mediated by the bumetanide-sensitive K+ transport system, and decreased the K+ efflux.
Montero
M C
MC
Departamento Fisiología y Biología Animal, Facultad de Farmacia, Universidad de Sevilla, Spain.
Ilundáin
A
A
D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002021:Buffers; D002034:Bumetanide / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology; D002645:Chickens; D007421:Intestine, Small / Q000187:drug effects / Q000378:metabolism*; D009994:Osmolar Concentration; D010042:Ouabain / Q000494:pharmacology; D011188:Potassium / Q000378:metabolism*; D015221:Potassium Channels / Q000187:drug effects / Q000502:physiology; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism
D002021:Buffers; D015221:Potassium Channels; D002034:Bumetanide; D010042:Ouabain; D000254:Sodium-Potassium-Exchanging ATPase; D011188:Potassium; D002118:Calcium