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Akahoya is a volcanic soil rich in alumina, primarily deposited in Kyushu, Japan. We have found that Akahoya adsorbs bacteria in the water surrounding cattle grazing areas, suggesting a potential for environmental purification. This study investigated the spectrum of microorganisms adsorbed by Akahoya using a column filled with Akahoya through which a suspension of microorganisms was passed. Shirasu soil, another volcanic soil with a different chemical composition, was used as a control. Akahoya effectively adsorbed a diverse range of microorganisms including Escherichia coli, Campylobacter jejuni, Vibrio parahaemolyticus, Salmonella Enteritidis, Staphylococcus aureus, Clostridium perfringens, spores of Bacillus subtilis and Bacillus anthracis, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), murine norovirus, and avian influenza virus (H3N2), whereas Shirasu soil did not adsorb any of the organisms examined. Moreover, bacteria naturally present in river water, such as aerobic bacteria, total coliforms, and Enterobacteriaceae as indicators of river contamination, as well as E. coli added artificially to sterilized river water, were reduced to below the detection limit (<1 CFU/mL) after being passed through Akahoya. Additionally, the number of viable E. coli continued to decrease after contact with Akahoya for 1 month, suggesting bactericidal effects. Notably, the adsorption of E. coli to Akahoya was influenced by the concentration of phosphate and the pH of the suspension due to the interaction between the surface phosphorylation of organisms and Al2O3, the major chemical component of Akahoya. The present results demonstrate the remarkable ability of Akahoya to remove phosphate and microbes, suggesting that Akahoya could be used for water purification processes.IMPORTANCEAlthough a safe and sufficient water supply is essential for the maintenance of hygienic conditions, a major challenge is to develop a comprehensive effective, sustainable, and cost-effective technological approach for the treatment and purification of contaminated water. In this study, we demonstrated that a novel volcanic soil, Akahoya, which has unlimited availability, is a highly effective adsorbent for a wide range of bacterial and viral pathogens, suggesting its potential as a sustainable resource for this purpose. It was suggested that the adsorption of microorganisms on Akahoya was mediated by phosphate groups present on the surface structures of microorganisms, which bind to the alumina component of Akahoya according to the phosphate concentration and pH of the liquid phase. The present findings highlight the exceptional ability of Akahoya to eliminate or reduce phosphate and microorganisms effectively in water purification processes, thus contributing to the development of efficient and sustainable solutions for addressing water pollution challenges.
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PURPOSE: Postoperative delirium is one of the most common complications after cardiovascular surgery in older adults. Benzodiazepines are a reported risk factor for delirium; however, there are no studies investigating remimazolam, a novel anesthetic agent. Therefore, we prospectively investigated the effect of remimazolam on postoperative delirium. METHODS: We included elective cardiovascular surgery patients aged ≥ 65 years at Hamamatsu University Hospital between August 2020 and February 2022. Patients who received general anesthesia with remimazolam were compared with those who received other anesthetics (control group). The primary outcome was delirium within 5 days after surgery. Secondary outcomes were delirium during intensive care unit stay and hospitalization, total duration of delirium, subsyndromal delirium, and differences in the Mini-Mental State Examination scores from preoperative to postoperative days 2 and 5. To adjust for differences in the groups' baseline covariates, we used stabilized inverse probability weighting as the primary analysis and propensity score matching as the sensitivity analysis. RESULTS: We enrolled 200 patients; 78 in the remimazolam group and 122 in the control group. After stabilized inverse probability weighting, 30.3% of the remimazolam group patients and 26.6% of the control group patients developed delirium within 5 days (risk difference, 3.8%; 95% confidence interval -11.5% to 19.1%; p = 0.63). The secondary outcomes did not differ significantly between the groups, and the sensitivity analysis results were similar to those for the primary analysis. CONCLUSION: Remimazolam was not significantly associated with postoperative delirium when compared with other anesthetic agents.
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Anestésicos , Delirio , Delirio del Despertar , Humanos , Anciano , Delirio del Despertar/complicaciones , Complicaciones Posoperatorias , Estudios Prospectivos , Delirio/etiología , BenzodiazepinasRESUMEN
BACKGROUND: Whether nerve block improves the quality of conscious sedation (CS) in patients undergoing transcatheter aortic valve implantation (TAVI) is unclear. This study investigated whether fascia iliaca block (FIB) reduced the remifentanil requirement and relieved pain in CS for TAVI.MethodsâandâResults: This prospective study randomized 72 patients scheduled for elective TAVI under CS into 2 groups, with (FIB) and without (control) FIB (n=36 in each group). The sedation targeted a Bispectral Index <90 with a Richmond Agitation-Sedation Scale of -2 to -1. Dexmedetomidine (0.7 µg/kg, i.v.) combined with remifentanil (0.03 µg/kg/min, i.v.) and propofol (0.3 mg/kg/h, i.v.) was used to commence sedation. FIB using 30 mL of 0.185% ropivacaine was implemented 2 min before TAVI. Patient sedation was maintained with dexmedetomidine (0.4 µg/kg/h, i.v.) supplemented with remifentanil (0-0.02 µg/kg/min, i.v.). Remifentanil (20 µg, i.v.) was used as a rescue dose for intraprocedural pain. Compared with the control group, FIB reduced the both the total (median [interquartile range] 83.0 [65.0-98.0] vs. 34.5 [26.0/45.8)] µg; P<0.001) and continuous (25.3 [20.9/31.5] vs. 9.5 [6.8/12.5] ng/kg/min; P<0.001) doses of remifentanil administered. CONCLUSIONS: FIB reduced the remifentanil requirement and relieved pain in patients undergoing TAVI with CS. Therefore, FIB improved the quality of CS in TAVI.
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The role of cytoskeleton dynamics in the oxidative stress toward human vasculature has been unclear. The current study examined whether the cytoskeleton-disrupting agent cytochalasin B reduces oxidative stress caused by high glucose in the human arterial smooth muscle. All experiments in the human omental arteries without endothelium or the cultured human coronary artery smooth muscle cells were performed in d-glucose (5.5 mmol/L). The exposure toward d-glucose (20 mmol/L) for 60 min reduced the relaxation or hyperpolarization to an ATP sensitive K+ channel (KATP) opener levcromakalim (10-8 to 3 × 10-6 mol/L and 3 × 10-6 mol/L, respectively). Cytochalasin B and a superoxide inhibitor Tiron, restored them similarly. Cytochalasin B reduced the NADPH oxidase activity, leading to a decrease in superoxide levels of the arteries treated with high d-glucose. Also, cytochalasin B impaired the F-actin constitution and the membrane translocation of an NADPH oxidase subunit p47phox in artery smooth muscle cells treated with high d-glucose. A clinical concentration of cytochalasin B prevented human vascular smooth muscle malfunction via the oxidative stress caused by high glucose. Regulation of the cytoskeleton may be essential to keep the normal vascular function in patients with hyperglycemia.
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Citocalasina B/farmacología , Citoesqueleto/metabolismo , Glucosa/efectos adversos , Hiperglucemia/metabolismo , Músculo Liso Vascular/metabolismo , Miocitos del Músculo Liso/metabolismo , Estrés Oxidativo/efectos de los fármacos , Adulto , Anciano , Células Cultivadas , Cromakalim/farmacología , Femenino , Humanos , Hiperglucemia/fisiopatología , Técnicas In Vitro , Masculino , Persona de Mediana Edad , Relajación Muscular/efectos de los fármacos , NADPH Oxidasas/metabolismo , Superóxidos/metabolismoRESUMEN
The purpose of this study was to assess the accuracy and reliability of a continuous blood glucose monitoring system (artificial endocrine pancreas; STG-55, Nikkiso, Tokyo, Japan) during pediatric cardiopulmonary bypass surgery. Twenty-five pediatric patients scheduled to undergo cardiovascular surgery with cardiopulmonary bypass (age 4 months to 11 years; body weight 5.6-59.7 kg) were enrolled. The glucose sensor line of the artificial endocrine pancreas was connected to the venous side of the cardiopulmonary bypass circuit and used for continuous blood glucose monitoring. We obtained 192 samples for blood gas assessment from the cardiopulmonary bypass circuit, and i-STAT (Abbott, East Windsor, NJ, USA) was used for conventional blood glucose assessment. The accuracies of continuous glucose measurements (STG-55) and conventional intermittent glucose measurements (i-STAT) during cardiopulmonary bypass were compared by means of Clarke error grid analysis. The results were divided into five zones, A, B, C, D, and E, and 78.6% of paired measurements were in zone A, while 21.4% were in zone B. We confirmed that the results of this continuous blood glucose monitoring system for cardiopulmonary bypass during pediatric cardiovascular surgery were highly reliable. An artificial endocrine pancreas may facilitate the safe use of intensive insulin therapy during pediatric cardiovascular surgery.
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Glucemia/metabolismo , Procedimientos Quirúrgicos Cardíacos , Puente Cardiopulmonar/métodos , Cardiopatías Congénitas/cirugía , Sistemas de Infusión de Insulina , Monitoreo Intraoperatorio/métodos , Niño , Preescolar , Femenino , Cardiopatías Congénitas/sangre , Humanos , Insulina/sangre , Masculino , Reproducibilidad de los ResultadosRESUMEN
BACKGROUND: Periodontal inflammation causes endothelial dysfunction of the systemic artery. However, it is unknown whether the use of local anesthetics during painful dental procedures alleviates periodontal inflammation and systemic endothelial function. This study was designed to examine whether the gingival or systemic injection of lidocaine prevents oxidative stress-induced endothelial dysfunction of the systemic artery in rats with intermittent periodontal inflammation caused by lipopolysaccharides (LPS). METHODS: Some rats received 1500 µg LPS injections to the gingiva during a week interval from the age of 8 to 11 weeks (LPS group). Lidocaine (3 mg/kg), LPS + lidocaine (3 mg/kg), LPS + lidocaine (1.5 mg/kg), and LPS + lidocaine (3 mg/kg, IP) groups simultaneously received gingival 1.5 or 3 mg/kg or IP 3 mg/kg injection of lidocaine on the same schedule as the gingival LPS. Isolated aortas or mandibles were subjected to the evaluation of histopathologic change, isometric force recording, reactive oxygen species, and Western immunoblotting. RESULTS: Mean blood pressure and heart rate did not differ among the control, LPS, LPS + lidocaine (3 mg/kg), and lidocaine (3 mg/kg) groups. LPS application reduced acetylcholine (ACh, 10 to 10 mol/L)-induced relaxation (29% difference at ACh 3 × 10 mol/L, P = .01), which was restored by catalase. Gingival lidocaine (1.5 and 3 mg/kg) dose dependently prevented the endothelial dysfunction caused by LPS application (24.5%-31.1% difference at ACh 3 × 10 mol/L, P = .006 or .001, respectively). Similar to the gingival application, the IP injection of lidocaine (3 mg/kg) restored the ACh-induced dilation of isolated aortas from rats with the LPS application (27.5% difference at ACh 3 × 10 mol/L, P < .001). Levels of reactive oxygen species were double in aortas from the LPS group (P < .001), whereas the increment was abolished by polyethylene glycol-catalase, gingival lidocaine (3 mg/kg), or the combination. The LPS induced a 4-fold increase in the protein expression of tumor necrosis factor-α in the periodontal tissue (P < .001), whereas the lidocaine (3 mg/kg) coadministration partly reduced the levels. Lidocaine application also decreased the protein expression of the nicotinamide adenine dinucleotide phosphate oxidase subunit p47phox, which was enhanced by the gingival LPS (5.6-fold increase; P < .001). CONCLUSIONS: Lidocaine preserved the aortic endothelial function through a decrease in arterial reactive oxygen species produced by nicotinamide adenine dinucleotide phosphate oxidase and periodontal tumor necrosis factor-α levels in rats with periodontal inflammation. These results suggest the beneficial effect of the gingival application of local anesthetics on the treatment of periodontal diseases on endothelial function of systemic arteries.
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Antiinflamatorios/farmacología , Antioxidantes/farmacología , Aorta/efectos de los fármacos , Endotelio Vascular/efectos de los fármacos , Encía/efectos de los fármacos , Lidocaína/farmacología , Estrés Oxidativo/efectos de los fármacos , Periodontitis/prevención & control , Vasodilatación/efectos de los fármacos , Animales , Antiinflamatorios/administración & dosificación , Antioxidantes/administración & dosificación , Aorta/metabolismo , Aorta/fisiopatología , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Endotelio Vascular/metabolismo , Endotelio Vascular/fisiopatología , Encía/metabolismo , Encía/fisiopatología , Mediadores de Inflamación/metabolismo , Inyecciones , Lidocaína/administración & dosificación , Lipopolisacáridos , Masculino , NADPH Oxidasas/metabolismo , Periodontitis/inducido químicamente , Periodontitis/metabolismo , Periodontitis/fisiopatología , Ratas Wistar , Especies Reactivas de Oxígeno/metabolismo , Factores de Tiempo , Factor de Necrosis Tumoral alfa/metabolismo , Vasodilatadores/farmacologíaRESUMEN
It is known that a variety of sized procoagulant vesicles that express tissue factor are released from several types of cells including monocytes by mechanisms related to the induction of apoptosis, while it has not yet been evaluated whether superoxide is involved in the production of such vesicles. Here, we report that a local anesthetic bupivacaine induces apoptosis in human monocytic cells THP-1 within a short observation period, where the shedding of procoagulant vesicles is associated. The property as procoagulant vesicles was evaluated using flow cytometry by the binding of FITC-conjugated fibrinogen to vesicles in the presence of fresh frozen plasma and the suppression of this binding by heparin. Bupivacaine (1 mg/ml) increased the apoptotic cells and procoagulant vesicles. LY294002 (100 µM), that inhibits the recruiting of intracellular component of NADPH oxidase to construct the activated form of this enzyme complex, or superoxide dismutase (1500 unit/ml) suppressed bupivacaine-provoked induction of apoptosis and the increase of procoagulant vesicles. We suggest that this simple experimental system is useful to explore the molecular mechanisms of action of superoxide in the shedding of procoagulant vesicles from human monocytic cells.
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Bupivacaína/farmacología , Micropartículas Derivadas de Células/efectos de los fármacos , Vesículas Extracelulares/química , Superóxidos/farmacología , Anestésicos Locales/farmacología , Apoptosis/efectos de los fármacos , Coagulantes , Humanos , Monocitos , NADPH Oxidasas/metabolismo , Superóxidos/metabolismo , Células THP-1RESUMEN
The aim of the present study was to evaluate the usefulness of a closed-loop system (STG-55; Nikkiso, Tokyo, Japan), a type of artificial endocrine pancreas for the continuous monitoring and control of intraoperative blood glucose, for preventing postoperative acute kidney injury (AKI) in patients undergoing hepatectomy. Thirty-eight patients were enrolled in this study. Glucose concentrations were controlled with either a manual injection of insulin based on a commonly used sliding scale (manual insulin group, n = 19) or the programmed infusion of insulin determined by the control algorithm of the artificial endocrine pancreas (programmed insulin group, n = 19). After the induction of anesthesia, a 20-G intravenous catheter was inserted into the peripheral forearm vein of patients in the programmed insulin group and connected to an artificial endocrine pancreas (STG-55). The target range for glucose concentrations was set to 100-150 mg/dL. The mean serum creatinine concentrations of preoperative, postoperative 24 and 48 h were 0.72, 0.78, and 0.79 mg/dL in the programmed insulin group, and 0.81, 0.95, and 1.03 mg/dL in the manual insulin group, respectively. Elevations in serum creatinine concentrations postoperative 48 h were significantly suppressed in the programmed insulin group. The STG-55 closed-loop system was effective for maintaining strict blood glucose control during hepatectomy with minimal variability in blood glucose concentrations and for suppressing elevations in serum creatinine concentrations. Strict blood glucose control by an artificial endocrine pancreas during hepatectomy may prevent postoperative AKI.
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Lesión Renal Aguda/prevención & control , Glucemia/análisis , Hepatectomía/efectos adversos , Páncreas Artificial , Complicaciones Posoperatorias/prevención & control , Lesión Renal Aguda/etiología , Anciano , Anciano de 80 o más Años , Creatinina , Femenino , Humanos , Insulina/uso terapéutico , Sistemas de Infusión de Insulina , Japón , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/etiología , Resultado del TratamientoRESUMEN
Whether high oxygen is harmful to the vascular function is unclear. The present study examined if high oxygen modifies vasodilator effect of cysteine via enhanced oxidative stress and thromboxane production. Rat mesenteric arteries with endothelium at 95 or 50 % oxygen were subjected to isometric force recordings, measurement of thromboxane B2 levels, determination of superoxide and peroxynitrite levels and evaluation of NADPH oxidase subunit protein expression, respectively. L-cysteine (0.01-3 mM) constricted or dilated arteries at 95 and 50 % oxygen, respectively. Thromboxane receptor antagonist SQ-29,548 (1 µM) abolished the constriction at 95 % oxygen. L-cysteine (3 mM) increased levels of thromboxane B2 in arteries upon 95 % oxygen application. L-cysteine relaxed arteries treated with superoxide inhibitor tiron (2 mM) or NADPH oxidase inhibitor gp91ds-tat (1 µM) irrespective of the oxygen concentration while ATP-sensitive K(+) channel inhibitor glibenclamide (1 µM) and cystathionine-γ-lyase (CSE) inhibitor DL-propargylglycine (10 mM) similarly abolished the relaxation. L-cysteine (3 mM) with 95 % oxygen augmented levels of superoxide as well as nitrotyrosine within the artery, concomitantly with enhanced membrane protein expression of NADPH oxidase subunit p47phox. The higher concentration of oxygen attenuates L-cysteine-induced vasodilation via superoxide production mediated by NADPH oxidase along with thromboxane A2 production, resulting in vasoconstriction. The increased levels of superoxide, as well as peroxynitrite, coexist with the impaired vasodilation related to ATP-sensitive K(+) channels and CSE. Higher oxygen with plasma cysteine may cause oxidative stress and vasoconstrictor prostanoid production in blood vessels.
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Cisteína/farmacología , Arterias Mesentéricas/metabolismo , Estrés Oxidativo , Oxígeno/farmacología , Tromboxanos/metabolismo , Vasodilatación , Sal Disódica del Ácido 1,2-Dihidroxibenceno-3,5-Disulfónico/farmacología , Alquinos/farmacología , Animales , Gliburida/farmacología , Glicina/análogos & derivados , Glicina/farmacología , Glicoproteínas/farmacología , Arterias Mesentéricas/efectos de los fármacos , Arterias Mesentéricas/fisiología , NADPH Oxidasas/antagonistas & inhibidores , NADPH Oxidasas/genética , NADPH Oxidasas/metabolismo , Ácido Peroxinitroso/metabolismo , Ratas , Ratas Wistar , Superóxidos/metabolismoRESUMEN
PURPOSE: The present study, conducted in rats, investigated whether propofol attenuates lipopolysaccharide (LPS)-triggered liver dysfunction via regulation of tumor necrosis factor (TNF)-α production in activated Kupffer cells. METHODS: Rats received LPS (500 µg/kg) under Urethane™ sedation (1 g/kg) in combination with propofol (5 mg/kg/h) or Intralipid™ from 1 h before to 6 h after LPS administration. Some rats were treated with 10 mg/kg gadolinium chloride (GdCl3) to induce Kupffer cell depletion. The serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), TNF-α mRNA and protein expression, caspase-3 activation and apoptosis were evaluated in hepatocytes. Immunofluorescence staining revealed expression of the pan-macrophage marker CD68 as well as TNF-α in Kupffer cells. RESULTS: ALT and AST serum levels increased approximately four-fold in LPS-exposed rats compared with Intralipid™-treated rats at 6 h after LPS administration, whereas propofol and GdCl3 reduced the LPS-induced increases. LPS simultaneously augmented TNF-α expression in Kupffer cells, followed by increased caspase-3 activity and apoptosis in hepatocytes. Immunofluorescence staining and immunoblotting assay showed that TNF-α expression in Kupffer cells was inhibited by propofol and GdCl3, resulting in a reduction of caspase-3 activity and apoptosis in LPS-treated rat hepatocytes. CONCLUSIONS: Propofol (5 mg/kg/h) attenuated LPS-triggered liver dysfunction via inhibition of TNF-α production in activated Kupffer cells. These results suggest that propofol is capable of inhibiting inflammation-induced liver dysfunction in vivo.
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Anestésicos Intravenosos/farmacología , Enfermedad Hepática Inducida por Sustancias y Drogas/prevención & control , Propofol/farmacología , Factor de Necrosis Tumoral alfa/metabolismo , Alanina Transaminasa/sangre , Animales , Antígenos CD/metabolismo , Antígenos de Diferenciación Mielomonocítica/metabolismo , Apoptosis/efectos de los fármacos , Aspartato Aminotransferasas/sangre , Caspasa 3/metabolismo , Emulsiones Grasas Intravenosas/farmacología , Gadolinio/toxicidad , Macrófagos del Hígado , Pruebas de Función Hepática , Masculino , Ratas , Ratas Sprague-DawleyRESUMEN
Although the accumulation of advanced glycation end-products (AGEs) of the Maillard reaction in our body is reported to increase with aging and is enhanced by the pathogenesis of lifestyle-related diseases such as diabetes, routine measurement of AGEs is not applied to regular clinical diagnoses due to the lack of conventional and reliable techniques for AGEs analyses. In the present study, a non-invasive AGEs measuring device was developed and the association between skin AGEs and diabetic complications was evaluated. To clarify the association between the duration of hyperglycemia and accumulation of skin fluorophores, diabetes was induced in mice by streptozotocin. As a result, the fluorophore in the auricle of live mice was increased by the induction of diabetes. Subsequent studies revealed that the fingertip of the middle finger in the non-dominant hand is suitable for the measurement of the fluorescence intensity by the standard deviation value. Furthermore, the fluorescence intensity was increased by the presence of diabetic microvascular complications. This study provides the first evidence that the accumulation of fluorophore in the fingertip increases with an increasing number of microvascular complications, demonstrating that the presence of diabetic microvascular complications may be predicted by measuring the fluorophore concentration in the fingertip.
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The peroxisome proliferator-activated receptor-γ (PPARγ) is an important regulator of lipid and glucose metabolism, and its activation is reported to suppress the progression of atherosclerosis. We have reported that 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) activate PPARγ in macrophages. However, it is not yet known whether statins activate PPARγ in other vascular cells. In the present study, we investigated whether statins activate PPARγ in smooth muscle cells (SMCs) and endothelial cells (ECs) and thus mediate anti-atherosclerotic effects. Human aortic SMCs (HASMCs) and human umbilical vein ECs (HUVECs) were used in this study. Fluvastatin and pitavastatin activated PPARγ in HASMCs, but not in HUVECs. Statins induced cyclooxygenase-2 (COX-2) expression in HASMCs, but not in HUVECs. Moreover, treatment with COX-2-siRNA abrogated statin-mediated PPARγ activation in HASMCs. Statins suppressed migration and proliferation of HASMCs, and inhibited lipopolysaccharide-induced expression of monocyte chemoattractant protein-1 (MCP-1) and tumor necrosis factor-α (TNF-α) in HASMCs. These effects of statins were abrogated by treatment with PPARγ-siRNA. Treatment with statins suppressed atherosclerotic lesion formation in Apoe(-/-) mice. In addition, transcriptional activity of PPARγ and CD36 expression were increased, and the expression of MCP-1 and TNF-α was decreased, in the aorta of statin-treated Apoe(-/-) mice. In conclusion, statins mediate anti-atherogenic effects through PPARγ activation in SMCs. These effects of statins on SMCs may be beneficial for the prevention of atherosclerosis.
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Aterosclerosis/tratamiento farmacológico , Aterosclerosis/metabolismo , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , PPAR gamma/metabolismo , Animales , Aorta/patología , Apolipoproteínas E/deficiencia , Apolipoproteínas E/metabolismo , Aterosclerosis/enzimología , Aterosclerosis/patología , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Quimiocina CCL2/metabolismo , Ciclooxigenasa 2/metabolismo , Progresión de la Enfermedad , Ácidos Grasos Monoinsaturados/farmacología , Fluvastatina , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Humanos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/farmacología , Indoles/farmacología , Lipopolisacáridos , Ratones Endogámicos C57BL , Miocitos del Músculo Liso/efectos de los fármacos , Miocitos del Músculo Liso/metabolismo , Miocitos del Músculo Liso/patología , FN-kappa B/metabolismo , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
Kynurenine is a potential contributor to hypotension in animal and human sepsis. The present study was designed to examine whether the voltage-dependent K(+) channels encoded by the KCNQ gene family (Kv7 channels) mediate vasodilator effects of kynurenine and whether modulation of these channels ameliorates hypotension caused by this compound. Rat aortas and mesenteric arteries or human omental arteries without endothelium were used. Some rings were incubated with the selective Kv7 channel inhibitor linopirdine (10 µM). l-Kynurenine (10 µM-1 mM) induced concentration-dependent relaxation in rat aortas and mesenteric arteries as well as human omental arteries, whereas linopirdine abolished the relaxation. l-Kynurenine (1 mM) produced hyperpolarization of vascular smooth muscle, which was reversed by linopirdine (10 µM). Wistar rats received l-kynurenine (1 mM) iv and subsequent linopirdine (10 µM) iv under 3% sevoflurane inhalation. l-Kynurenine iv caused hypotension, whereas linopirdine iv partially reversed it. In conclusion, kynurenine dilates arteries from rats as well as humans via Kv7 channels in the vascular smooth muscle. In rats, this tryptophan metabolite causes hypotension, which is partly counteracted by Kv7 channel inhibition. These results suggest that modulation of Kv7 channels may be a novel strategy to treat hypotension induced by the kynurenine.