Panel A shows line traces of LVCM calcium currents with and without SMTC during voltage-clamp pulses. Panel B shows a line graph of L-type calcium current density versus membrane voltage for LVCM with and without SMTC. Panel C shows line traces of RVCM calcium currents with and without SMTC during voltage-clamp pulses. Panel D shows a line graph of L-type calcium current density versus membrane voltage for RVCM with and without SMTC.
Effects of nNOS inhibition on L-type Ca 2+ channel current (ICa,L ) in LVCM and RVCM. (A) Representative ICa,L traces recorded from LVCM under control conditions and following SMTC treatment using the perforated whole-cell configuration. Solid black line, LVCM; black dotted line, LVCM + SMTC. Cells were held at −40 mV and depolarized to test potentials between −40 and +50 mV in 10 mV increments. (B) I-V relationships of peak ICa,L normalized to cell capacitance (pA/pF) in LVCM and LVCM + SMTC. Cell-level comparison of peak ICa,L density at the voltage producing maximal inward current demonstrated a statistically significant difference between groups (P < 0.0001). (C) Representative ICa,L traces recorded from RVCM under control conditions and following SMTC treatment using the same voltage protocol as in panel A. Solid gray line, RVCM; gray dotted line, RVCM + SMTC. (D) I-V relationships of peak ICa,L normalized to cell capacitance (pA/pF) in RVCM and RVCM + SMTC (P = 0.0008). Sample sizes were as follows: LVCM, n = 38 cells; LVCM + SMTC, n = 36 cells; RVCM, n = 38 cells; RVCM + SMTC, n = 32 cells.