Lumbriculus variegatus: A novel organism for in vivo pharmacology education

Pharmacology graduates require an understanding of both in vitro and in vivo drug responses but there has been a decline in animal use in pharmacology education over the last 30 years. To address this, we present the novel invertebrate model, Lumbriculus variegatus, for in vivo testing of drugs in a teaching environment. We have developed two novel behavioral assays: the stereotypical movement assay, which measures the effect of drugs on the ability of L. variegatus to perform stereotypical movements following tactile stimulation, and the free locomotion assay, which measures drug effects on unstimulated movement. We report the effects of compounds with diverse pharmacodynamic properties on L. variegatus using these assays. The ryanodine receptor antagonist, dantrolene, altered the unstimulated movement of L. variegatus at 5 μM, whereas stimulated movement was inhibited at ≥25 μM. Lidocaine, a voltage-gated sodium channel blocker, and quinine, a nonselective sodium and potassium channel blocker, reduced both stimulated and unstimulated L. variegatus movement at ≥0.5 mM. Inhibitory effects of quinine persisted for up to 24 h after drug removal, whereas lidocaine effects were reduced 10 min after drug removal. Herein, we provide proof-of-concept utilization of L. variegatus as an organism for use in in vivo pharmacology education but without regulatory constraints or the need for specialized equipment and training.