[Show abstract][Hide abstract] ABSTRACT: We investigated the effect of Lipofundin MCT/LCT and Intralipid on acetylcholine-induced nitric oxide- (NO-) mediated relaxation in rat aorta to determine which lipid emulsion (LE) is more potent in terms of inhibition of NO-induced relaxation. Dose-response curves of responses induced by acetylcholine, the calcium ionophore A23187, and sodium nitroprusside were generated using isolated rat aorta with or without LE. The effect of Lipofundin MCT/LCT on acetylcholine-induced endothelial nitric oxide synthase (eNOS) phosphorylation in human umbilical vein endothelial cells (HUVECs) was investigated using western blotting. Lipofundin MCT/LCT (0.1 and 0.2%) attenuated acetylcholine-induced relaxation in endothelium-intact aorta with or without tiron, whereas 0.2% Intralipid only inhibited relaxation. Lipofundin MCT/LCT inhibited relaxation induced by the calcium ionophore A23187 and sodium nitroprusside in endothelium-intact aorta, but Lipofundin MCT/LCT had no effect on sodium nitroprusside-induced relaxation in the endothelium-denuded aorta. Combined pretreatment with
-arginine plus Lipofundin MCT/LCT increased acetylcholine-induced maximal relaxation in endothelium-intact aorta compared with Lipofundin MCT/LCT alone.
-Arginine attenuated Lipofundin MCT/LCT-mediated inhibition of acetylcholine-induced eNOS phosphorylation in HUVECs. Taken together, Lipofundin MCT/LCT attenuated acetylcholine-induced NO-mediated relaxation via an inhibitory effect on the endothelium including eNOS, which is proximal to activation of guanylyl cyclase.
[Show abstract][Hide abstract] ABSTRACT: Purpose
Intravenous lipid emulsions have been used to treat the systemic toxicity of local anesthetics. The goal of this in vitro study was to examine the effects of lipid emulsions on the norepinephrine-mediated reversal of vasodilation induced by high doses of levobupivacaine, ropivacaine, and mepivacaine in isolated endothelium-denuded rat aorta, and to determine whether such effects are associated with the lipid solubility of local anesthetics.
Materials and Methods
The effects of lipid emulsions (0.30, 0.49, 1.40, and 2.61%) on norepinephrine concentration-responses in high-dose local anesthetic (6×10-4 M levobupivacaine, 2×10-3 M ropivacaine, and 7×10-3 M mepivacaine)-induced vasodilation of isolated aorta precontracted with 60 mM KCl were assessed. The effects of lipid emulsions on local anesthetic- and diltiazem-induced vasodilation in isolated aorta precontracted with phenylephrine were also assessed.
Lipid emulsions (0.30%) enhanced norepinephrine-induced contraction in levobupivacaine-induced vasodilation, whereas 1.40 and 2.61% lipid emulsions enhanced norepinephrine-induced contraction in both ropivacaine- and mepivacaine-induced vasodilation, respectively. Lipid emulsions (0.20, 0.49 and 1.40%) inhibited vasodilation induced by levobupivacaine and ropivacaine, whereas 1.40 and 2.61% lipid emulsions slightly attenuated mepivacaine (3×10-3 M)-induced vasodilation. In addition, lipid emulsions attenuated diltiazem-induced vasodilation. Lipid emulsions enhanced norepinephrine-induced contraction in endothelium-denuded aorta without pretreatment with local anesthetics.
Taken together, these results suggest that lipid emulsions enhance the norepinephrine-mediated reversal of local anesthetic-induced vasodilation at toxic anesthetic doses and inhibit local anesthetic-induced vasodilation in a manner correlated with the lipid solubility of a particular local anesthetic.
Preview · Article · Nov 2013 · Yonsei medical journal
[Show abstract][Hide abstract] ABSTRACT: The goals of this study were to determine which lipid emulsion (Intralipid(®) and Lipofundin MCT/LCT(®)) is more effective in reversing high-dose levobupivacaine-induced reduced vasoconstriction in isolated rat aortas and to examine the associated cellular mechanisms with a particular focus on the endothelium. Two lipid emulsion concentration-response curves were generated using high-dose levobupivacaine-induced reduced vasoconstriction and vasodilation of isolated aortas pretreated with or without 60 mM KCl. Endothelial nitric oxide synthase (eNOS) and caveolin-1 phosphorylation were measured in rat aortic tissue treated with levobupivacaine in the presence or absence of lipid emulsion. Dichlorofluorescein oxidation, a measure of reactive oxygen species production, was measured in lipid emulsion-treated human umbilical vein endothelial cells. In levobupivacaine (0.3 mM)-induced reduced vasoconstriction of isolated aorta, the magnitude of the Intralipid(®)- and Lipofundin MCT/LCT(®)-mediated reversal was not significantly different. Lipid emulsion reversal of levobupivacaine-induced reduced vasoconstriction was greater in endothelium-intact aortas than in endothelium-denuded aortas. The two lipid emulsions similarly inhibited levobupivacaine-induced eNOS phosphorylation in aortic tissue. Pretreatment with both lipid emulsions increased dichlorofluorescein oxidation. Both Intralipid(®) and Lipofundin MCT/LCT(®) are equally effective for vascular tone recovery from high-dose levobupivacaine-induced reduced vasoconstriction. This reversal is mediated partially by decreasing nitric oxide bioavailability.
[Show abstract][Hide abstract] ABSTRACT: Purpose:
Micro-vibration culture system was examined to determine the effects on mouse and human embryo development and possible improvement of clinical outcomes in poor responders.
Materials and methods:
The embryonic development rates and cell numbers of blastocysts were compared between a static culture group (n = 178) and a micro-vibration culture group (n = 181) in mice. The embryonic development rates and clinical results were compared between a static culture group (n = 159 cycles) and a micro-vibration culture group (n = 166 cycles) in poor responders. A micro-vibrator was set at a frequency of 42 Hz, 5 s/60 min duration for mouse and human embryo development.
The embryonic development rate was significantly improved in the micro-vibration culture group in mice (p < 0.05). The cell numbers of mouse blastocysts were significantly higher in the micro-vibration group than in the static culture group (p < 0.05). In the poor responders, the rate of high grade embryos was not significantly improved in the micro-vibration culture group on day 3. However, the optimal embryonic development rate on day 5 was improved in the micro-vibration group, and the total pregnancy rate and implantation rate were significantly higher in the micro-vibration group than in the static culture group (p < 0.05).
Micro-vibration culture methods have a beneficial effect on embryonic development in mouse embryos. In poor responders, the embryo development rate was improved to a limited extent under the micro-vibration culture conditions, but the clinical results were significantly improved.
No preview · Article · May 2013 · Journal of Assisted Reproduction and Genetics
[Show abstract][Hide abstract] ABSTRACT: Mepivacaine is an aminoamide local anesthetic with an intermediate duration that intrinsically produces vasoconstriction both in vivo and in vitro. This study investigated the arachidonic acid metabolic pathways involved in mepivacaine-induced contraction, and elucidated the associated cellular mechanism with a particular focus on extracellular signal-regulated kinase (ERK) in endothelium-denuded rat aorta. Isolated rat thoracic aortic rings were suspended for isometric tension recording. Cumulative mepivacaine concentration-response curves were generated in the presence or absence of the following inhibitors: quinacrine dihydrochloride, nordihydroguaiaretic acid, phenidone, AA-861, indomethacin, NS-398, SC-560, fluconazole, PD 98059, and verapamil. Mepivacaine-induced ERK phosphorylation, 5-lipoxygenase (5-LOX) expression, and cyclooxygenase (COX)-2 expression in rat aortic smooth muscle cells were detected by Western blot analysis in the presence or absence of inhibitors. Mepivacaine produced tonic contraction in isolated endothelium-denuded rat aorta. Quinacrine dihydrochloride, nordihydroguaiaretic acid, phenidone, AA-861, NS-398, PD 98059, and verapamil attenuated mepivacaine-induced contraction in a concentration-dependent manner. However, fluconazole had no effect on mepivacaine-induced contraction. PD 98059, quinacrine dihydrochloride, nordihydroguaiaretic acid, AA-861, phenidone, and indomethacin attenuated mepivacaine-induced ERK phosphorylation. Mepivacaine upregulated 5-LOX and COX-2 expression. These results suggest that mepivacaine-induced contraction involves ERK activation, which is primarily mediated by the 5-LOX pathway and in part by the COX-2 pathway.
Full-text · Article · Apr 2013 · Canadian Journal of Physiology and Pharmacology
[Show abstract][Hide abstract] ABSTRACT: Intravenous lipid emulsion has been used to treat systemic toxicity of local anesthetics. The goals of this in vitro study were to determine the ability of two lipid emulsions (Intralipid® and Lipofundin® MCT/LCT) to reverse toxic dose local anesthetic-induced vasodilation in isolated rat aortas.
Isolated endothelium-denuded aortas were suspended for isometric tension recording. Vasodilation was induced by bupivacaine (3 × 10(-4) M), ropivacaine (10(-3) M), lidocaine (3 × 10(-3) M), or mepivacaine (7 × 10(-3) M) after precontraction with 60 mM KCl. Intralipid® and Lipofundin® MCT/LCT were then added to generate concentration-response curves. We also assessed vasoconstriction induced by 60 mM KCl, 60 mM KCl with 3 × 10(-4) M bupivacaine, and 60 mM KCl with 3 × 10(-4) M bupivacaine plus 1.39% lipid emulsion (Intralipid® or Lipofundin® MCT/LCT).
The two lipid emulsions reversed vasodilation induced by bupivacaine, ropivacaine, and lidocaine but had no effect on vasodilation induced by mepivacaine. Lipofundin® MCT/LCT was more effective than Intralipid® in reversing bupivacaine-induced vasodilation. The magnitude of lipid emulsion-mediated reversal of vasodilation induced by high-dose local anesthetics was as follows (from highest to lowest): 3 × 10(-4) M bupivacaine-induced vasodilation, 10(-3) M ropivacaine-induced vasodilation, and 3 × 10(-3) M lidocaine-induced vasodilation.
Lipofundin® MCT/LCT-mediated reversal of bupivacaine-induced vasodilation was greater than that of Intralipid®; however, the two lipid emulsions equally reversed vasodilation induced by ropivacaine and lidocaine. The magnitude of lipid emulsion-mediated reversal of vasodilation appears to be correlated with the lipid solubility of the local anesthetic.
Full-text · Article · Apr 2013 · Korean journal of anesthesiology
[Show abstract][Hide abstract] ABSTRACT: According to the current guidelines for blood pressure monitoring, clinicians are recommended to measure blood pressure by completely exposing the upper arm. However, it is a common practice that blood pressure is measured with the cuff placed over the sleeve or with the sleeve rolled up. We therefore conducted this study to examine whether there are any differences in blood pressure measurements among the three different settings: the sleeve group, the rolled sleeve group, and the bare arm group.
We conducted the current study in 141 male and female adult patients who visited our clinical department. In these patients, we took repeatedly blood pressure measurements using the same automatic oscillometric device on three different settings. Then, we analyzed the results with the use of randomized block design analysis of variance.
The mean values of systolic blood pressure (SBP) between the first reading and those of the second reading were 128.5 ± 10.6 mm Hg in the sleeve group, 128.3 ± 10.8 mm Hg in the rolled sleeve group, and 128.3 ± 10.7 mm Hg in the bare arm group. These results indicate that there were no significant differences among the three groups (P = 0.32). In addition, the mean values of diastolic blood pressure (DBP) between the first reading and those of the second reading were 80.7 ± 6.1 mm Hg in the sleeve group, 80.7 ± 6.1 mm Hg in the rolled sleeve group, and 80.6 ± 5.9 mm Hg in the bare arm group. These results indicate that there were no significant differences among the three groups (P = 0.77). In addition, based on the age, sex, past or current history of hypertension or diabetes mellitus, the thickness of sleeve, weight, a drinking history, and a smoking history, there were no significant differences in SBP and DBP among the three groups.
There were no significant differences in blood pressure measurements between the three different settings (the sleeve group, the rolled sleeve group, and the bare arm group).
Preview · Article · Mar 2013 · Korean Journal of Family Medicine
[Show abstract][Hide abstract] ABSTRACT: Background:
It has traditionally been known that there is normally a difference in blood pressure (BP) between the two arms; there is at least 20 mm Hg difference in the systolic blood pressure (SBP) and 10 mm Hg difference in the diastolic blood pressure (DBP). However, recent epidemiologic studies have shown that there are between-arm differences of < 5 mm Hg in simultaneous BP measurements. The purposes of this study is to examine whether there are between-arm differences in simultaneous BP measurements obtained from ambulatory patients without cardiovascular diseases and to identify the factors associated these differences.
We examined 464 patients who visited the outpatient clinic of Gangneung Asan Hospital clinical department. For the current analysis, we excluded patients with ischemic heart disease, stroke, arrhythmia, congestive heart failure, or hyperthyroidism. Simultaneous BP measurements were obtained using the Omron MX3 BP monitor in both arms. The inter-arm difference (IAD) in BP was expressed as the relative difference (right-arm BP [R] minus left-arm BP [L]: R - L) and the absolute difference (|R - L|).
The mean absolute IAD in SBP and DBP were 3.19 ± 2.38 and 2.41 ± 1.59 mm Hg, respectively, in men and 2.61 ± 2.18 and 2.25 ± 2.01 mm Hg, respectively, in women. In men, there were 83.8% of patients with the IAD in SBP of ≤ 6 mm Hg, 98.1% with the IAD in SBP of ≤ 10 mm Hg, 96.5% with the IAD in DBP of ≤ 6 mm Hg and 0% with the IAD in DBP of > 10 mm Hg. In women, 89.6% of patients had IAD in SBP of ≤ 6 mm Hg, 92.1% with IAD in DBP of ≤ 6 mm Hg, and 0% with IAD in SBP of > 10 mm Hg or IAD in DBP of > 10 mm Hg. Gangneung Asan Hospital clinical series of patients showed that the absolute IAD in SBP had a significant correlation with cardiovascular risk factors such as the 10-year Framingham cardiac risk scores and higher BP in men and higher BP in women. However, the absolute IAD in SBP and DBP had no significant correlation with the age, obesity, smoking, drinking, hyperlipidemia, diabetes, metabolic syndrome, and renal function.
Our results showed that there were no significant between-arm differences in simultaneous BP measurements. It was also shown that most of the ambulatory patients without cardiovascular diseases had an IAD in SBP of < 10 mm Hg and an IAD in DBP of < 6 mm Hg.
Preview · Article · Mar 2013 · Korean Journal of Family Medicine
[Show abstract][Hide abstract] ABSTRACT: Aminoamide local anesthetics induce vasoconstriction in vivo and in vitro. The goals of this in vitro study were to investigate the potency of local anesthetic-induced vasoconstriction and to identify the physicochemical property (octanol/buffer partition coefficient, pKa, molecular weight, or potency) of local anesthetics that determines their potency in inducing isolated rat aortic ring contraction. Cumulative concentration-response curves to local anesthetics (levobupivacaine, ropivacaine, lidocaine, and mepivacaine) were obtained from isolated rat aorta. Regression analyses were performed to determine the relationship between the reported physicochemical properties of local anesthetics and the local anesthetic concentration that produced 50% (ED(50)) of the local anesthetic-induced maximum vasoconstriction. We determined the order of potency (ED(50)) of vasoconstriction among local anesthetics to be levobupivacaine > ropivacaine > lidocaine > mepivacaine. The relative importance of the independent variables that affect the vasoconstriction potency is octanol/buffer partition coefficient > potency > pKa > molecular weight. The ED(50) in endothelium-denuded aorta negatively correlated with the octanol/buffer partition coefficient of local anesthetics (r(2) = 0.9563; P < 0.001). The potency of the vasoconstriction in the endothelium-denuded aorta induced by local anesthetics is determined primarily by lipid solubility and, in part, by other physicochemical properties including potency and pKa.
Full-text · Article · Jun 2012 · BioMed Research International
[Show abstract][Hide abstract] ABSTRACT: Mepivacaine is an aminoamide-linked local anesthetic with an intermediate duration that intrinsically produces vasoconstriction both in vivo and in vitro. The aims of this in-vitro study were to examine the direct effect of mepivacaine in isolated rat aortic rings and to determine the associated cellular mechanism with a particular focus on endothelium-derived vasodilators, which modulate vascular tone. In the aortic rings with or without endothelium, cumulative mepivacaine concentration-response curves were generated in the presence or absence of the following antagonists: N(ω)-nitro-L-arginine methyl ester [L-NAME], indomethacin, fluconazole, methylene blue, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one [ODQ], verapamil, and calcium-free Krebs solution. Mepivacaine produced vasoconstriction at low concentrations (1 × 10(-3) and 3 × 10(-3) mol/L) followed by vasodilation at a high concentration (1 × 10(-2) mol/L). The mepivacaine-induced contraction was higher in endothelium-denuded aortae than in endothelium-intact aortae. Pretreatment with L-NAME, ODQ, and methylene blue enhanced mepivacaine-induced contraction in the endothelium-intact rings, whereas fluconazole had no effect. Indomethacin slightly attenuated mepivacaine-induced contraction, whereas verapamil and calcium-free Krebs solution more strongly attenuated this contraction. The vasoconstriction induced by mepivacaine is attenuated mainly by the endothelial nitric oxide - cyclic guanosine monophosphate pathway. In addition, mepivacaine-induced contraction involves cyclooxygenase pathway activation and extracellular calcium influx via voltage-operated calcium channels.
Full-text · Article · Jun 2012 · Canadian Journal of Physiology and Pharmacology
[Show abstract][Hide abstract] ABSTRACT: Levobupivacaine is a long-acting amide local anesthetic that intrinsically produces vasoconstriction both in vivo and in vitro. Levobupivacaine increases intracellular calcium concentrations ([Ca(2+)](i)) in vascular smooth muscle cells. The goals of this in vitro study were to investigate whether levobupivacaine-induced contraction is associated with increased Ca(2+) sensitivity and to identify the protein kinases involved in mediating contraction in response to levobupivacaine in isolated rat aortic smooth muscle. The effect of levobupivacaine and potassium chloride (KCl) on the [Ca(2+)](i) and tension was measured simultaneously with acetoxymethyl ester of fura-2-loaded aortic strips. Cumulative levobupivacaine concentration-response curves were generated in the presence or absence of the following antagonists: GF 109203X; Y-27632; genistein; SP600125; PD 98059; and SB 203580. Levobupivacaine-induced protein kinase C (PKC), extracellular signal-regulated kinase (ERK), and c-Jun NH(2)-terminal kinase (JNK) phosphorylation and Rho-kinase (ROCK-2) membrane translocation were detected in rat aortic vascular smooth muscle cells using Western blotting. The slope of the [Ca(2+)](i)-tension curve for levobupivacaine was higher than that for KCl. Y-27632, GF 109203X, and SP600125 attenuated levobupivacaine-induced contraction in a concentration-dependent manner. Genistein, PD 98059, and SB 203580 attenuated levobupivacaine-induced contraction. Pretreatment with GF 109203X and Y-27632 inhibited levobupivacaine-induced PKC phosphorylation and Rho-kinase (ROCK-2) membrane translocation, respectively. Pretreatment with SP600125 or PD 98059 attenuated the levobupivacaine-induced phosphorylation of JNK and ERK, respectively. These results indicate that levobupivacaine-induced contraction involving an increase in myofilament Ca(2+) sensitivity involves the primary activation of Rho-kinase-, PKC-, and JNK-mediated pathways of rat aortic smooth muscle.
No preview · Article · Feb 2012 · European journal of pharmacology