Nitric oxide modulates Ca2+ channel currents in rat sympathetic neurons.

The effects of nitric oxide on the Ca2+ channel currents of adult rat superior cervical ganglion neurons were investigated using the whole-cell patch-clamp technique. Nitric oxide-containing compounds sodium nitroprusside and S-nitroso-N-acetyl-penicillamine increased the amplitude of Ca2+ currents by intracellular application. In addition, both sodium nitroprusside and S-nitroso-N-acetylpenicillamine reduced norepinephrine-induced inhibition of Ca2+ currents. The results suggest that nitric oxide might be involved in the modulation of Ca(2+)-dependent neurotransmission in sympathetic neurons.