Effects of CO as a Signaling Molecule at the Frog Neuromuscular Junction

Abstract

Carbon monoxide (CO) has been characterized as a neurotransmitter in the gut, blood vessels and brain. However, little is known about the effects of CO as a neurotransmitter on the neuromuscular junction. In order to test these effects, the motor neuron of the frog Rana pipiens sartorious muscle was stimulated in Ringers solution containing CO. The resulting decrease in end plate potentials (EPPs) taken from the sartorious muscle tentatively indicate that the presence of CO causes decreased EPP intensity. This suggests that CO acts to increase the amount of cGMP formed and thus causes hyperpolarization and relaxation of the muscle.