Mepivacaine attenuates vasodilation induced by ATP-sensitive potassium channels in rat aorta

Combined inferior alveolar nerve block anaesthesia and local infiltration anaesthesia in extraction of impacted mandibular third molars: a randomised controlled trial

Aim To compare the anaesthetic effect of combination of inferior alveolar nerve block anaesthesia and local infiltration anaesthesia with nerve block anaesthesia techniques in the extraction of mandibular third molars.Materials and methods One hundred and fifty healthy adult volunteers were divided into three groups and were administered three different local anaesthetic techniques before tooth extractions: group A (inferior alveolar nerve, lingual nerve and buccal nerve block anaesthesia with lidocaine), group B (inferior alveolar nerve, lingual nerve and buccal nerve block anaesthesia with mepivacaine) and group C (inferior alveolar nerve block anaesthesia with lidocaine and infiltration anaesthesia with mepivacaine). The patients' reported pain on anaesthesia injection and tooth extraction, the surgeon's assessment of anaesthetic effect, the severity of intra-operative bleeding and post-operative complications were evaluated.Results There was no significant difference in visual analogue scale (VAS)-pain of anaesthesia among the three groups. Compared with groups A and B, group C had reduced VAS-pain of tooth extraction scores. Additionally, the surgeon's assessment of anaesthetic effect improved and intra-operative bleeding decreased.Conclusions The combination of inferior alveolar nerve block and infiltration anaesthesia provides a stronger anaesthetic effect in the extraction of mandibular third molars.

Levobupivacaine-induced vasoconstriction involves caldesmon phosphorylation mediated by tyrosine kinase-induced ERK phosphorylation

The goals of this study were to examine the cellular signaling pathways associated with the phosphorylation of caldesmon, the phosphorylation-dependent inhibitory protein of myosin phosphatase (CPI-17), and the 20-kDa regulatory light chain of myosin (MLC₂₀) induced by levobupivacaine in isolated rat aortas. The effects of genistein, tyrphostin 23, GF109203X, PD98059, Y-27632, 1-butanol, and ML-7 HCl on levobupivacaine-induced contraction were assessed. The effect of genistein on the simultaneous calcium-tension curves induced by levobupivacaine was examined. The effects of GF109203X, genistein, PD98059 and extracellular signal-regulated kinase (ERK) siRNA on levobupivacaine-induced caldesmon phosphorylation were investigated. The effect of genistein on the ERK and tyrosine phosphorylation induced by levobupivacaine was examined. The effect of GF109203X, PD98059, Y-27632, SP600125, and ML-7 HCl on the levobupivacaine-induced phosphorylation of CPI-17 and MLC₂₀ were investigated. Genistein, tyrphostin 23, GF109203X, PD98059, Y-27632, ML-7 HCl, and 1-butanol attenuated levobupivacaine-induced contraction. Genistein caused a right downward shift of the calcium-tension curves induced by levobupivacaine. Genistein attenuated levobupivacaine-induced phosphorylation of protein tyrosine, ERK and caldesmon. PD98059, ERK siRNA and GF109203X attenuated levobupivacaine-induced caldesmon phosphorylation. GF109203X, Y-27632, SP600125, ML-7 HCl and PD98059 attenuated CPI-17 phosphorylation and MLC₂₀ phosphorylation induced by levobupivacaine. These results suggest that levobupivacaine-induced caldesmon phosphorylation contributing to levobupivacaine-induced contraction is mediated by a pathway involving ERK, which is activated by tyrosine kinase or protein kinase C (PKC). The phosphorylation of CPI-17 and MLC₂₀ induced by levobupivacaine is mediated by cellular signaling pathways involving PKC, Rho-kinase, and c-Jun NH₂-terminal kinase or PKC, Rho-kinase, ERK, and myosin light chain kinase.

Linoleic Acid Attenuates the Toxic Dose of Bupivacaine-Mediated Reduction of Vasodilation Evoked by the Activation of Adenosine Triphosphate-Sensitive Potassium Channels

The goal of this study was to investigate the effect of lipid emulsion on a toxic dose of local anesthetic-mediated reduction of vasodilation evoked by the ATP-sensitive potassium (K_ATP) channel agonist levcromakalim. The effect of lipid emulsion (LE) and linoleic acid on the local anesthetic-mediated reduction of vasodilation and membrane hyperpolarization evoked by levcromakalim was assessed in isolated endothelium-denuded vessels (rat aorta and mesenteric artery) and aortic vascular smooth muscle cells. The effect of LE and linoleic acid on K_ATP channel activity in transfected HEK-293 cells was investigated, as was the effect of LE on bupivacaine concentration. The efficacy of LE in attenuating the local anesthetic-mediated reduction of vasodilation evoked by levcromakalim was correlated with the lipid solubility of the local anesthetic. Linoleic acid attenuated the bupivacaine-mediated reduction of vasodilation evoked by levcromakalim. LE decreased the bupivacaine-mediated reduction of membrane hyperpolarization evoked by levcromakalim but did not significantly alter the mepivacaine-mediated reduction. LE and linoleic acid both reversed the bupivacaine-mediated decrease of K_ATP activity and enhanced K_ATP activity. LE decreased the bupivacaine concentration. Linoleic acid may be the major contributor to LE-induced attenuation of bupivacaine-mediated reduction of vasodilation evoked by levcromakalim via the direct activation of K_ATP channels and indirect effects.