Cholinergic and GABAergic innervation regulate activity of electrogenic ionic pump in earthworm somatic muscle cells

摘要

Carbacholine reduced, while baclofen and norepinephrine increased resting membrane potential in earthworm somatic muscle cells. In the presence of carbacholine, neither norepinephrine, nor baclofen hyperpolarized the membrane. Ouabain decreased resting potential and abolished the effects of carbacholine, norepinephrine, and baclofen on membrane potential. It was hypothesized that carbacholine directly inhibited the ouabain-sensitive component of Na+/K+ pump and abolished the activating effect of norepinephrine and baclofen.