Abstract
BACKGROUND: Although mepivacaine has a known biphasic action on the aortic and coronary artery in several animal species, its effects on the lingual and pulmonary artery are not well understood and it is not yet known whether mepivacaine produces vasoconstriction in these vessels. The present study aims to investigate the direct effects of mepivacaine on swine lingual, pulmonary and coronary arterial endothelium-denuded rings. METHODS: Artery rings were perfused with isotonic 40 mM KCl until a stable constricted plateau was reached. The rings were then perfused with isotonic 40 mM KCl plus a particular concentration of mepivacaine (0.4 μM, 4.0 μM, 40 μM, 0.4 mM and 4.0 mM). The isometric tension strengths in each experiment were normalized to the strength of the isometric tension immediately before mepivacaine perfusion and expressed as a percentage. RESULTS: Mepivacaine at 0.4 to 40 μM did not significantly alter 40 mM KCl-induced contraction in the lingual, pulmonary and coronary arterial rings. In contrast, mepivacaine at 4 mM produced attenuated vasoconstriction in the lingual, pulmonary and coronary arterial compared with isotonic 40 mM KCl. CONCLUSIONS: Mepivacaine produced vasoconstriction at lower concentrations, followed by attenuated vasoconstriction at higher concentrations on swine lingual, pulmonary and coronary arterial endothelium-denuded rings. Mepivacaine (4 μM) appeared to increase isotonic 40 mM KCl-induced contraction, followed by attenuated vasoconstriction at 4 mM. Dentists using 3 % mepivacaine should take into consideration that the risk of complications may be increased if more than six mepivacaine cartridges are used in dental treatment or minor surgery, or if over 15 ml of mepivacaine is administered to a patient with cardiovascular complications during general anesthesia for oral maxillofacial surgery.