The use of hyperosmolar, intracellular-like solutions for the isolation of epithelial cells from guinea-pig small intestine.

Isolated small intestine epithelial cells were prepared by using either (a) hyperosmolar, low sodium, high potassium containing (intracellular-like) solutions, or (b) isosmolar, high sodium, low potassium containing (extracellular-like) solutions. Both (a) and (b) cells show high viability as estimated by Trypan blue exclusion, oxygen consumption, cellular ATP content, lactate-dehydrogenase liberation, intracellular ion concentrations and significant Na+-dependent alanine and uridine uptakes. Although (a) and (b) cells show in the cold similar ion concentration, after reincubation at 37 degrees C for 30 min (a) cells show intracellular ion concentrations of 31 mM Na, 129 mM K and 88 mM Cl, whilst (b) cells have 71 mM Na, 93 mM K and 102 mM Cl. Cells prepared with (a) concentrate much more alanine and uridine than cells prepared with (b), probably because the latter have a lower Na+ gradient across the plasma membrane. Cells prepared with intracellular-like solutions would be an ideal system to study Na+-dependent transport mechanisms and the regulatory systems of intracellular ion concentrations.