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 μM) was added to the bath. In cell-attached and cell-excised patches of the basolateral membrane nonselective cation channels (γ = 38 pS, 35° C) were recorded. It is concluded that nonselective cation channels are activated by PGE2 and forskolin. The channels could be involved in cell proliferation.