Toxic Dose

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Ju-tae Sohn - One of the best experts on this subject based on the ideXlab platform.

  • Lipid emulsion inhibits the vasodilation induced by a Toxic Dose of amlodipine in isolated rat aortae.
    International Journal of Medical Sciences, 2019
    Co-Authors: Soo Hee Lee, Yeran Hwang, Ji-yoon Kim, Hyun-jin Kim, Sung Il Bae, Seongyeong Tak, Ju-tae Sohn
    Abstract:

    The goal of this study was to examine the effect of lipid emulsion on the vasodilation induced in isolated endothelium-denuded rat aortae by a Toxic Dose of amlodipine. We examined the effects of lipid emulsion and verapamil on amlodipine-induced vasodilation. We also examined the effects of a mixture of lipid emulsion and amlodipine, as well as the centrifuged aqueous extract (CAE) obtained by ultracentrifuging such a mixture and then removing the upper lipid layer, on amlodipine-induced vasodilation. The effect of lipid emulsion on the amlodipine concentration was examined. Lipid emulsion attenuated amlodipine-induced vasodilation in isolated aortae. Both CAE and lipid emulsion containing amlodipine inhibited amlodipine-induced vasodilation. However, there was no significant difference in amlodipine-induced vasodilation between aortae treated with CAE and those treated with lipid emulsion containing amlodipine. Verapamil inhibited amlodipine-induced vasodilation. Lipid emulsion decreased the concentration of amlodipine. Lipid emulsion attenuated the vasodilation induced by a Toxic amlodipine Dose in NaF-precontracted aortae. The data show that lipid emulsion inhibited the vasodilation induced by a Toxic amlodipine Dose in isolated rat aortae by reducing the concentration of amlodipine. Amlodipine-induced vasodilation seems to be mediated mainly by blockade of L-type calcium channels and partially by inhibition of the Rho-kinase pathway.

  • Lipid emulsion attenuates the vasodilation induced by a Toxic Dose of a calcium channel blocker through its partitioning into the lipid phase.
    General Physiology and Biophysics, 2019
    Co-Authors: Soo Hee Lee, Jeong-min Hong, Ji-yoon Kim, Hyun-jin Kim, Sung Il Bae, Yunsik Shin, Ju-tae Sohn
    Abstract:

    The present in vitro study examined whether lipid emulsion attenuates the vasodilation evoked by Toxic Doses of calcium channel blockers (bepridil, verapamil, nifedipine and diltiazem) via their partitioning into the lipid phase. The effects of the calcium channel blockers alone, the lipid emulsion and calcium channel blocker mixture, and the centrifuged aqueous extract (CAE) obtained from ultracentrifugation of the lipid emulsion and calcium channel blocker mixture on isolated endothelium-denuded rat aortas precontracted with phenylephrine were observed. The effects of lipid emulsion on calcium channel blocker concentration in the Krebs solution were examined using ultraperformance liquid chromatography. A mixture of lipid emulsion with either bepridil or verapamil and the corresponding CAE more effectively attenuated vasodilation than either bepridil or verapamil alone, whereas the vasodilation induced by the mixture of lipid emulsion and either bepridil or verapamil was not significantly different from that induced by the corresponding CAE. The magnitude of the lipid emulsion-mediated reduction in vasodilation and calcium channel blocker concentration was as follows: bepridil > verapamil > nifedipine or diltiazem. These results suggest that lipid emulsion attenuates vasodilation induced by a Toxic Dose of bepridil and verapamil, seemingly through partitioning of the calcium channel blocker into the lipid phase.

  • A Lipid Emulsion Reverses Toxic-Dose Bupivacaine-Induced Vasodilation during Tyrosine Phosphorylation-Evoked Contraction in Isolated Rat Aortae.
    International Journal of Molecular Sciences, 2017
    Co-Authors: Soo Hee Lee, Seong-chun Kwon, Mun Hwan Choi, Il-woo Shin, Sebin Kang, Miyeong Park, Jeong-min Hong, Ju-tae Sohn
    Abstract:

    The goal of this in vitro study was to examine the effect of a lipid emulsion on Toxic-Dose bupivacaine-induced vasodilation in a model of tyrosine phosphatase inhibitor sodium orthovanadate-induced contraction in endothelium-denuded rat aortae and to elucidate the associated cellular mechanism. The effect of a lipid emulsion on vasodilation induced by a Toxic Dose of a local anesthetic during sodium orthovanadate-induced contraction was examined. In addition, the effects of various inhibitors, either bupivacaine alone or a lipid emulsion plus bupivacaine, on protein kinase phosphorylation induced by sodium orthovanadate in rat aortic vascular smooth muscle cells was examined. A lipid emulsion reversed the vasodilation induced by bupivacaine during sodium orthovanadate-induced contraction. The lipid emulsion attenuated the bupivacaine-mediated inhibition of the sodium orthovanadate-induced phosphorylation of protein tyrosine, c-Jun NH₂-terminal kinase (JNK), myosin phosphatase target subunit 1 (MYPT1), phospholipase C (PLC) γ-1 and extracellular signal-regulated kinase (ERK). These results suggest that a lipid emulsion reverses Toxic-Dose bupivacaine-induced vasodilation during sodium orthovanadate-induced contraction via the activation of a pathway involving either tyrosine kinase, JNK, Rho-kinase and MYPT1 or tyrosine kinase, PLC γ-1 and ERK, and this reversal is associated with the lipid solubility of the local anesthetic and the induction of calcium sensitization.

  • Lipid Emulsion Inhibits Apoptosis Induced by a Toxic Dose of Verapamil via the Delta-Opioid Receptor in H9c2 Rat Cardiomyoblasts.
    Cardiovascular Toxicology, 2016
    Co-Authors: Mun Hwan Choi, Soo Hee Lee, Il-woo Shin, Sebin Kang, Jeong Yeol Han, Ju-tae Sohn
    Abstract:

    The goals of this study were to investigate the effects of lipid emulsion (LE) on apoptosis induced by a Toxic Dose of verapamil in H9c2 cells and to elucidate the associated cellular mechanism. The effects of LE alone and combined with an inhibitor on the decreases in cell counts and viability induced by verapamil and diltiazem were examined using the MTT assay. The effects of verapamil alone, combined LE and verapamil treatment, and combined inhibitor, LE and verapamil treatment on cleaved caspase-3, caspase-8 and Bax expression, were examined using Western blotting. The effects of verapamil alone and combined with LE on the number of TUNEL-positive H9c2 cells were also examined. LE attenuated the decreases in cell counts and viability induced by verapamil and diltiazem. However, the magnitude of the LE-mediated attenuation of decreased cell viability was enhanced by verapamil compared with diltiazem treatment. Naloxone, naltrindole hydrochloride, LY294002 and MK-2206 inhibited the LE-mediated attenuation of increased cleaved caspase-3 and caspase-8 expression induced by verapamil. LE attenuated the increase in the number of TUNEL-positive cell induced by verapamil. These results suggest that LE attenuates apoptosis induced by verapamil via activation of the delta-opioid receptor, phosphoinositide 3-kinase and Akt.

  • Lipid emulsion inhibits vasodilation induced by a Toxic Dose of bupivacaine by suppressing bupivacaine-induced PKC and CPI-17 dephosphorylation but has no effect on vasodilation induced by a Toxic Dose of mepivacaine.
    The Korean Journal of Pain, 2016
    Co-Authors: Hyunhoo Cho, Soo Hee Lee, Seong-chun Kwon, Sebin Kang, Jiseok Baik, Ju-tae Sohn
    Abstract:

    BACKGROUND The goal of this in vitro study was to investigate the effect of lipid emulsion on vasodilation caused by Toxic Doses of bupivacaine and mepivacaine during contraction induced by a protein kinase C (PKC) activator, phorbol 12,13-dibutyrate (PDBu), in an isolated endothelium-denuded rat aorta. METHODS The effects of lipid emulsion on the Dose-response curves induced by bupivacaine or mepivacaine in an isolated aorta precontracted with PDBu were assessed. In addition, the effects of bupivacaine on the increased intracellular calcium concentration ([Ca2+]i) and contraction induced by PDBu were investigated using fura-2 loaded aortic strips. Further, the effects of bupivacaine, the PKC inhibitor GF109203X and lipid emulsion, alone or in combination, on PDBu-induced PKC and phosphorylation-dependent inhibitory protein of myosin phosphatase (CPI-17) phosphorylation in rat aortic vascular smooth muscle cells (VSMCs) was examined by western blotting. RESULTS Lipid emulsion attenuated the vasodilation induced by bupivacaine, whereas it had no effect on that induced by mepivacaine. Lipid emulsion had no effect on PDBu-induced contraction. The magnitude of bupivacaine-induced vasodilation was higher than that of the bupivacaine-induced decrease in [Ca2+]i. PDBu promoted PKC and CPI-17 phosphorylation in aortic VSMCs. Bupivacaine and GF109203X attenuated PDBu-induced PKC and CPI-17 phosphorylation, whereas lipid emulsion attenuated bupivacaine-mediated inhibition of PDBu-induced PKC and CPI-17 phosphorylation. CONCLUSIONS These results suggest that lipid emulsion attenuates the vasodilation induced by a Toxic Dose of bupivacaine via inhibition of bupivacaine-induced PKC and CPI-17 dephosphorylation. This lipid emulsion-mediated inhibition of vasodilation may be partly associated with the lipid solubility of local anesthetics.

An Keun Kim - One of the best experts on this subject based on the ideXlab platform.

  • sub Toxic Dose of apigenin sensitizes hepg2 cells to trail through erk dependent up regulation of trail receptor dr5
    Molecules and Cells, 2013
    Co-Authors: Eunyoung Kim, Mihi Yang, An Keun Kim
    Abstract:

    Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is regarded as a promising candidate for anticancer therapy due to its selective Toxicity to cancer cells. Nevertheless, because of TRAIL resistance in some cancer cells, combined treatment with sensitizing agents is required to enhance the anticancer potential of TRAIL. In this study, we investigated the underlying mechanism of apigenin-induced sensitization of HepG2 cells to TRAIL-induced cell death. Synergistic induction of apoptosis by combination was confirmed by examining the typical morphology changes of apoptosis, PARP-cleavage, and activation of effector caspases. Z-VAD-fmk, a pan-caspase inhibitor, inhibited the enhanced cell death by combined treatment of apigenin and TRAIL, demonstrating that a caspase-dependent pathway is involved in apigenin/TRAIL-mediated apoptosis. In addition, we found that apigenin/ TRAIL co-treatment up-regulates DR5 cell surface expression. The synergistic induction of cell death by the apigenin/ TRAIL combination was significantly attenuated by DR5 blocking chimera antibody. Next, using pharmacological inhibitors, we found that ERK activation is involved in the induction of DR5 expression. Inhibition of ERK1/2 by U0126 significantly decreased the apigenin/TRAIL-induced DR5 expression and apoptosis. Taken together, our results indicate that apigenin can enhance the apoptotic effect of TRAIL via ERK-induced up-regulation of DR5.

Soo Hee Lee - One of the best experts on this subject based on the ideXlab platform.

  • Lipid emulsion inhibits the vasodilation induced by a Toxic Dose of amlodipine in isolated rat aortae.
    International Journal of Medical Sciences, 2019
    Co-Authors: Soo Hee Lee, Yeran Hwang, Ji-yoon Kim, Hyun-jin Kim, Sung Il Bae, Seongyeong Tak, Ju-tae Sohn
    Abstract:

    The goal of this study was to examine the effect of lipid emulsion on the vasodilation induced in isolated endothelium-denuded rat aortae by a Toxic Dose of amlodipine. We examined the effects of lipid emulsion and verapamil on amlodipine-induced vasodilation. We also examined the effects of a mixture of lipid emulsion and amlodipine, as well as the centrifuged aqueous extract (CAE) obtained by ultracentrifuging such a mixture and then removing the upper lipid layer, on amlodipine-induced vasodilation. The effect of lipid emulsion on the amlodipine concentration was examined. Lipid emulsion attenuated amlodipine-induced vasodilation in isolated aortae. Both CAE and lipid emulsion containing amlodipine inhibited amlodipine-induced vasodilation. However, there was no significant difference in amlodipine-induced vasodilation between aortae treated with CAE and those treated with lipid emulsion containing amlodipine. Verapamil inhibited amlodipine-induced vasodilation. Lipid emulsion decreased the concentration of amlodipine. Lipid emulsion attenuated the vasodilation induced by a Toxic amlodipine Dose in NaF-precontracted aortae. The data show that lipid emulsion inhibited the vasodilation induced by a Toxic amlodipine Dose in isolated rat aortae by reducing the concentration of amlodipine. Amlodipine-induced vasodilation seems to be mediated mainly by blockade of L-type calcium channels and partially by inhibition of the Rho-kinase pathway.

  • Lipid emulsion attenuates the vasodilation induced by a Toxic Dose of a calcium channel blocker through its partitioning into the lipid phase.
    General Physiology and Biophysics, 2019
    Co-Authors: Soo Hee Lee, Jeong-min Hong, Ji-yoon Kim, Hyun-jin Kim, Sung Il Bae, Yunsik Shin, Ju-tae Sohn
    Abstract:

    The present in vitro study examined whether lipid emulsion attenuates the vasodilation evoked by Toxic Doses of calcium channel blockers (bepridil, verapamil, nifedipine and diltiazem) via their partitioning into the lipid phase. The effects of the calcium channel blockers alone, the lipid emulsion and calcium channel blocker mixture, and the centrifuged aqueous extract (CAE) obtained from ultracentrifugation of the lipid emulsion and calcium channel blocker mixture on isolated endothelium-denuded rat aortas precontracted with phenylephrine were observed. The effects of lipid emulsion on calcium channel blocker concentration in the Krebs solution were examined using ultraperformance liquid chromatography. A mixture of lipid emulsion with either bepridil or verapamil and the corresponding CAE more effectively attenuated vasodilation than either bepridil or verapamil alone, whereas the vasodilation induced by the mixture of lipid emulsion and either bepridil or verapamil was not significantly different from that induced by the corresponding CAE. The magnitude of the lipid emulsion-mediated reduction in vasodilation and calcium channel blocker concentration was as follows: bepridil > verapamil > nifedipine or diltiazem. These results suggest that lipid emulsion attenuates vasodilation induced by a Toxic Dose of bepridil and verapamil, seemingly through partitioning of the calcium channel blocker into the lipid phase.

  • Linoleic Acid Attenuates the Toxic Dose of Bupivacaine-Mediated Reduction of Vasodilation Evoked by the Activation of Adenosine Triphosphate-Sensitive Potassium Channels
    International Journal of Molecular Sciences, 2018
    Co-Authors: Soo Hee Lee, Seong-chun Kwon, Jeong-min Hong, Ji-yoon Kim, Hyun-jin Kim, Dawon Kang, Eun-jin Kim, Sung Il Bae
    Abstract:

    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 (KATP) 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 KATP 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 KATP activity and enhanced KATP 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 KATP channels and indirect effects.

  • A Lipid Emulsion Reverses Toxic-Dose Bupivacaine-Induced Vasodilation during Tyrosine Phosphorylation-Evoked Contraction in Isolated Rat Aortae.
    International Journal of Molecular Sciences, 2017
    Co-Authors: Soo Hee Lee, Seong-chun Kwon, Mun Hwan Choi, Il-woo Shin, Sebin Kang, Miyeong Park, Jeong-min Hong, Ju-tae Sohn
    Abstract:

    The goal of this in vitro study was to examine the effect of a lipid emulsion on Toxic-Dose bupivacaine-induced vasodilation in a model of tyrosine phosphatase inhibitor sodium orthovanadate-induced contraction in endothelium-denuded rat aortae and to elucidate the associated cellular mechanism. The effect of a lipid emulsion on vasodilation induced by a Toxic Dose of a local anesthetic during sodium orthovanadate-induced contraction was examined. In addition, the effects of various inhibitors, either bupivacaine alone or a lipid emulsion plus bupivacaine, on protein kinase phosphorylation induced by sodium orthovanadate in rat aortic vascular smooth muscle cells was examined. A lipid emulsion reversed the vasodilation induced by bupivacaine during sodium orthovanadate-induced contraction. The lipid emulsion attenuated the bupivacaine-mediated inhibition of the sodium orthovanadate-induced phosphorylation of protein tyrosine, c-Jun NH₂-terminal kinase (JNK), myosin phosphatase target subunit 1 (MYPT1), phospholipase C (PLC) γ-1 and extracellular signal-regulated kinase (ERK). These results suggest that a lipid emulsion reverses Toxic-Dose bupivacaine-induced vasodilation during sodium orthovanadate-induced contraction via the activation of a pathway involving either tyrosine kinase, JNK, Rho-kinase and MYPT1 or tyrosine kinase, PLC γ-1 and ERK, and this reversal is associated with the lipid solubility of the local anesthetic and the induction of calcium sensitization.

  • Lipid Emulsion Inhibits Apoptosis Induced by a Toxic Dose of Verapamil via the Delta-Opioid Receptor in H9c2 Rat Cardiomyoblasts.
    Cardiovascular Toxicology, 2016
    Co-Authors: Mun Hwan Choi, Soo Hee Lee, Il-woo Shin, Sebin Kang, Jeong Yeol Han, Ju-tae Sohn
    Abstract:

    The goals of this study were to investigate the effects of lipid emulsion (LE) on apoptosis induced by a Toxic Dose of verapamil in H9c2 cells and to elucidate the associated cellular mechanism. The effects of LE alone and combined with an inhibitor on the decreases in cell counts and viability induced by verapamil and diltiazem were examined using the MTT assay. The effects of verapamil alone, combined LE and verapamil treatment, and combined inhibitor, LE and verapamil treatment on cleaved caspase-3, caspase-8 and Bax expression, were examined using Western blotting. The effects of verapamil alone and combined with LE on the number of TUNEL-positive H9c2 cells were also examined. LE attenuated the decreases in cell counts and viability induced by verapamil and diltiazem. However, the magnitude of the LE-mediated attenuation of decreased cell viability was enhanced by verapamil compared with diltiazem treatment. Naloxone, naltrindole hydrochloride, LY294002 and MK-2206 inhibited the LE-mediated attenuation of increased cleaved caspase-3 and caspase-8 expression induced by verapamil. LE attenuated the increase in the number of TUNEL-positive cell induced by verapamil. These results suggest that LE attenuates apoptosis induced by verapamil via activation of the delta-opioid receptor, phosphoinositide 3-kinase and Akt.

Eunyoung Kim - One of the best experts on this subject based on the ideXlab platform.

  • sub Toxic Dose of apigenin sensitizes hepg2 cells to trail through erk dependent up regulation of trail receptor dr5
    Molecules and Cells, 2013
    Co-Authors: Eunyoung Kim, Mihi Yang, An Keun Kim
    Abstract:

    Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is regarded as a promising candidate for anticancer therapy due to its selective Toxicity to cancer cells. Nevertheless, because of TRAIL resistance in some cancer cells, combined treatment with sensitizing agents is required to enhance the anticancer potential of TRAIL. In this study, we investigated the underlying mechanism of apigenin-induced sensitization of HepG2 cells to TRAIL-induced cell death. Synergistic induction of apoptosis by combination was confirmed by examining the typical morphology changes of apoptosis, PARP-cleavage, and activation of effector caspases. Z-VAD-fmk, a pan-caspase inhibitor, inhibited the enhanced cell death by combined treatment of apigenin and TRAIL, demonstrating that a caspase-dependent pathway is involved in apigenin/TRAIL-mediated apoptosis. In addition, we found that apigenin/ TRAIL co-treatment up-regulates DR5 cell surface expression. The synergistic induction of cell death by the apigenin/ TRAIL combination was significantly attenuated by DR5 blocking chimera antibody. Next, using pharmacological inhibitors, we found that ERK activation is involved in the induction of DR5 expression. Inhibition of ERK1/2 by U0126 significantly decreased the apigenin/TRAIL-induced DR5 expression and apoptosis. Taken together, our results indicate that apigenin can enhance the apoptotic effect of TRAIL via ERK-induced up-regulation of DR5.

J Park - One of the best experts on this subject based on the ideXlab platform.

  • Lipid emulsion alleviates the vasodilation and mean blood pressure decrease induced by a Toxic Dose of verapamil in isolated rat aortae and an in vivo rat model.
    Human & Experimental Toxicology, 2017
    Co-Authors: I-w Shin, Sung-gap Lee, J Park, M S Woo, J-m Hong, J Kim, J-t Sohn
    Abstract:

    This study aimed to examine the effects of lipid emulsion on the vasodilation and cardiovascular depression induced by Toxic Doses of calcium channel blockers. The effects of lipid emulsion on the vasodilation induced by bepridil, verapamil, nifedipine, and diltiazem were investigated in isolated endothelium-denuded rat aortae. The effect of lipid emulsion on the comparable hemodynamic depression induced by the continuous infusion of a Toxic Dose of either verapamil or diltiazem was examined in an in vivo rat model. The results showed the following decreasing order for the magnitude of lipid emulsion-mediated inhibition of vasodilation: bepridil, verapamil, nifedipine, and diltiazem. Lipid emulsion (0.5-2%) reversed the vasodilation induced by a Toxic Dose of verapamil, whereas only a higher concentration (2%) reversed the vasodilation induced by a Toxic Dose of diltiazem. Pretreatment with lipid emulsion alleviated the systolic and mean blood pressure decreases induced by a Toxic Dose of verapamil, whereas it had no effect on the decrease induced by diltiazem. Taken together, these results suggest that lipid emulsion alleviates the severe vasodilation and systolic blood pressure decrease induced by a Toxic Dose of verapamil, and this alleviation appears to be associated with the relatively high lipid solubility of verapamil.

  • lipid emulsion inhibits vasodilation induced by a Toxic Dose of bupivacaine via attenuated dephosphorylation of myosin phosphatase target subunit 1 in isolated rat aorta
    International Journal of Medical Sciences, 2015
    Co-Authors: Hyojin Byon, Seong-chun Kwon, Mun Jeoung Choi, J Park, Youngju Lee, Yeran Hwang, Jiseok Baik, Ju-tae Sohn
    Abstract:

    Lipid emulsions are widely used for the treatment of systemic Toxicity that arises from local anesthetics. The goal of this in vitro study was to examine the cellular mechanism associated with the lipid emulsion-mediated attenuation of vasodilation induced by a Toxic Dose of bupivacaine in isolated endothelium-denuded rat aorta. The effects of lipid emulsion on vasodilation induced by bupivacaine, mepivacaine, and verapamil were assessed in isolated aorta precontracted with phenylephrine, the Rho kinase stimulant NaF, and the protein kinase C activator phorbol 12,13-dibutyrate (PDBu). The effects of Rho kinase inhibitor Y-27632 on contraction induced by phenylephrine or NaF were assessed. The effects of bupivacaine on intracellular calcium concentrations ([Ca(2+)]i) and tension induced by NaF were simultaneously measured. The effects of bupivacaine alone and lipid emulsion plus bupivacaine on myosin phosphatase target subunit 1 (MYPT1) phosphorylation induced by NaF were examined in rat aortic vascular smooth muscle cells. In precontracted aorta, the lipid emulsion attenuated bupivacaine-induced vasodilation but had no effect on mepivacaine-induced vasodilation. Y-27632 attenuated contraction induced by either phenylephrine or NaF. The lipid emulsion attenuated verapamil-induced vasodilation. Compared with phenylephrine-induced precontracted aorta, bupivacaine-induced vasodilation was slightly attenuated in NaF-induced precontracted aorta. The magnitude of the bupivacaine-induced vasodilation was higher than that of a bupivacaine-induced decrease in [Ca(2+)]i. Bupivacaine attenuated NaF-induced MYPT1 phosphorylation, whereas lipid emulsion pretreatment attenuated the bupivacaine-induced inhibition of MYPT1 phosphorylation induced by NaF. Taken together, these results suggest that lipid emulsions attenuate bupivacaine-induced vasodilation via the attenuation of inhibition of MYPT1 phosphorylation evoked by NaF.