Bupivacaine inhibits endothelin-1 evoked increases in intracellular calcium in model sensory neurons
Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
Background: Endothelin-1 (ET-1) induces pain and sensitization by activating the Gq protein-coupled receptor endothelin-A (ETA). Activation of ETA receptors on nociceptors membrane evokes intracellular calcium transients and excites the neurons, which presumably underlie ET-1’s pro-nociceptive effects in vivo. Local anesthetics inhibit the Gqprotein-coupled signaling of several inflammatory and pain modulating mediators. In this study, we aimed to investigate the actions of local anesthetics on the ETA-mediated increases in intracellular calcium in ND7/104 sensory neurons.
Methods: Increases in intracellular calcium were measured by the fluorescent indicator fura-2-AM loaded in a sensory neuron-derived cell line (ND7/104) expressing ETA receptors. Cells were pre-incubated with local anesthetic before ET-1 exposure and peak amplitudes were measured.
Results: Bupivacaine suppressed ET-1 responses in a concentration-dependent and non-competitive manner with an IC50of 3.79 + 1.63 mM. Bupivacaine at 6 mM reduced Emax for ET-1 from 50.07 (95% CI 46.08 – 54.06) to 27.30 (95% CI 21.11 – 33.49). The actions of bupivacaine occurred quickly and were rapidly reversible. In contrast, 10 mM lidocaine and 10 mM QX-314, separately, had no effect.
Conclusion: Bupivacaine inhibits ETA-mediated calcium transients at clinically achieved concentrations. This suggests that some of bupivacaine’s beneficial effects might be due to an interaction with ET-1 signaling.
Place, publisher, year, edition, pages
2014. , 54 p.
"Endothelin-1" "local anesthetics" "G protein-coupled receptor" "endothelin-A receptor" "model sensory neurons" "calcium"
Pharmacology and Toxicology
IdentifiersURN: urn:nbn:se:uu:diva-217190OAI: oai:DiVA.org:uu-217190DiVA: diva2:692499
Harvard Medical School
Subject / course
Master of Science Programme in Pharmacy
Nyberg, Fred, Professor
Hallberg, Mathias, Professor