The effect of cGMP in rabbit auricle as studied by a cut-end method.

Cyclic GMP was applied to the rabbit right auricle by a cut-end method. The nucleotide decreased the spontaneous rate, hyperpolarized the cell membrane and reduced the amplitude and the slow component of the action potential. It also decreased the force of contraction. These results suggest that cGMP may be the mediator of the action of acetylcholine in the rabbit auricle.