Myomodulin is a neuromodulatory peptide found in molluscs, insects, and gastropods. In leeches, myomodulin inhibits activity of the Na+/K+ pump, increasing hyperpolarization-activated current I(h) and altering heart neuron spike and burst frequency. In glial cell membranes, myomodulin evokes membrane outward currents and elicits increases in K+ conductance. Across many cellular models, myomodulin modulates K+, Na+, and Ca2+ current amplitudes. Additionally, myomodulin increases muscle contraction frequency, increasing gut motility.