Nitric oxide activation of a potassium channel (BKCa) in feline lower esophageal sphincter

Figure 1 Representative traces (last 300 ms of trace shown) and quantification of the effect of sodium nitroprusside (10^-4 mol/L) on elicited outward K⁺ currents using a ramp protocol from -140 to +60 mV of lower esophageal sphincter circular (n = 13) and sling (n = 8) smooth muscle cells. The maximal total outward current was similar in isolated smooth muscle cells from the lower esophageal sphincter (LES) circular and sling regions. The nitric oxide donor sodium nitroprusside (SNP) increased outward potassium currents of LES circular smooth muscle cells. In contrast, SNP did not significantly cause an increase in the outward K⁺ currents in LES sling muscle. ^bP < 0.001.