Nonselective cation channels in cells of the crypt-base of rat distal colon

Cells in the base of isolated intact crypts of rat distal colon were investigated with the slow whole-cell patch-clamp technique with nystatin in the patch pipette. Addition of either prostaglandin E2 or forskolin to the bath depolarized the cell from -74 mV to -27 mV. This depolarization was reversed when bath Na+ was replaced by N-methyl-D-glucamine (NMDG+), or when flufenamic acid (50 microM) was added to the bath. In cell-attached and cell-excised patches of the basolateral membrane nonselective cation channels (gamma = 38 pS, 35 degrees C) were recorded. It is concluded that nonselective cation channels are activated by PGE2 and forskolin. The channels could be involved in cell proliferation.