Effect of S-methyl-l-thiocitrulline (SMTC, 1 μM) on outward K+ currents of glomus cells in sham, sham + Ad.nNOS, CHF, and CHF + Ad.nNOS groups. Peak K+ currents measured in response to a test pulse from −80 to +70 mV. Data are mean ± SE, n = 8 cells from 5 rabbits in each group. *P < 0.05 vs. before treated with SMTC in each group.