A mini Cl- channel sensitive to external pH in the basolateral membrane of guinea-pig parietal cells.

摘要: 1. Voltage-independent whole-cell Cl- currents were recorded from both single, isolated parietal cells and within gastric glands obtained the fundus of guinea-pig stomach. 2. The rapidly suppressed by a channel blocker, NPPB (5-nitro-2-(3-phenylpropylamino)-benzoate), added to (basolateral) bathing solution in concentration-dependent manner with half-maximal inhibition concentration 12 microM. 3. selectivity sequence among anions was I- > Br- F-, corresponding Eisenman's I. 4. independent cytosolic Ca2+, cyclic AMP, GMP, GTP-gamma-S cell volume, not affected application acid secretagogues, omeprazol, arachidonic or prostaglandin E2. 5. Reduction pH immediately inhibited current pK (-log KD) 6.3, whereas changes intracellular had no effect. 6. single-channel conductance estimated be 0.46-0.6 pS variance noise analysis during acidic pH. 7. It is concluded that pH-sensitive 'mini' channels, sub-picosiemens unitary conductance, exist basolateral membrane cells.