Anesthetic management of a patient with dilated cardiomyopathy and purpura for interventional thrombectomy of both femoral artery: Case report.

RATIONALE: Anesthesia management of patients with dilated cardiomyopathy (DCM) has always been a challenge for anesthesiologists. Eighty percent of patients with DCM have heart failure as the first symptom, which may be accompanied by arrhythmias, thromboembolism, etc. Thrombosis is a significant contributing factor to adverse cardiovascular and cerebrovascular events, and its risk is severely underestimated in the anesthetic management of DCM. PATIENT CONCERNS: We present a case of a 54-year-old hypersensitive female patient with dilated cardiomyopathy and purpura who underwent an interventional thrombectomy under general anesthesia following a lower limb thromboembolism. DIAGNOSIS: Patient underwent an interventional thrombectomy under general anesthesia, with in situ thrombosis occurring during the surgery. INTERVENTIONS: After maintaining stable hemodynamics, proceed with the intervention to retrieve the embolus. OUTCOME: Patients in the advanced DCM developed acute thrombosis twice during embolization. LESSONS: This case discusses the causes of intraoperative thrombosis and summarizes and reflects on the anesthesia management of this case, which has always been one of the difficult points for anesthesiologists to master. In the anesthesia management of DCM patients, it is also necessary to maintain hemodynamic stability, enhance perioperative coagulation management, use anticoagulants rationally, and avoid the occurrence of thrombotic events.

Stubborn hypoxemia after mild to moderate sedation and analgesia: A case report.

INTRODUCTION: Atelectasis typically denotes the partial or complete collapse of lung segments, lobes, or lobules in individuals, leading to a compromised respiratory function. The prevalence of perioperative atelectasis may be significantly underestimated, particularly among patients subjected to general anesthesia. PATIENT CONCERNS: This article conducts a retrospective analysis of a case involving refractory hypoxemia in a patient with a liver tumor who was admitted to Yanbian University Affiliated Hospital (Yanbian Hospital) after undergoing mild-to-moderate sedation and analgesia outside the operating room. DIAGNOSIS: Based on the results of CT examination and present history, the patient was diagnosed with intraoperative atelectasis. INTERVENTION: After the surgery, the patient was transferred to the recovery ward, where nasal oxygen therapy and nebulized inhalation treatment were administered. Vital signs were closely monitored at the bedside, gradually returning to the preoperative baseline. OUTCOME: Postoperatively, the patient developed atelectasis, with the percentage of lung opacity shown in the image decreasing from 9.2% of the total thoracic cage area to 8.4%. CONCLUSION: During non-intubated intravenous anesthesia, patients with compromised pulmonary conditions are more susceptible to refractory hypoxemia. Therefore, a personalized approach should be adopted regarding oxygen concentration and the dosage and type of medication. Additionally, preparations for appropriate airway management measures are essential to safeguard patient safety in the event of respiratory issues.

Cathepsin S activity controls chronic stress-induced muscle atrophy and dysfunction in mice.

Exposure to chronic psychological stress (CPS) is an intractable risk factor for inflammatory and metabolic diseases. Lysosomal cysteinyl cathepsins play an important role in human pathobiology. Given that cathepsin S (CTSS) is upregulated in the stressed vascular and adipose tissues, we investigated whether CTSS participates in chronic stress-induced skeletal muscle mass loss and dysfunction, with a special focus on muscle protein metabolic imbalance and apoptosis. Eight-week-old male wildtype (CTSS+/+) and CTSS-knockout (CTSS-/-) mice were randomly assigned to non-stress and variable-stress groups. CTSS+/+ stressed mice showed significant losses of muscle mass, dysfunction, and fiber area, plus significant mitochondrial damage. In this setting, stressed muscle in CTSS+/+ mice presented harmful alterations in the levels of insulin receptor substrate 2 protein content (IRS-2), phospho-phosphatidylinositol 3-kinase, phospho-protein kinase B, and phospho-mammalian target of rapamycin, forkhead box-1, muscle RING-finger protein-1 protein, mitochondrial biogenesis-related peroxisome proliferator-activated receptor-γ coactivator-α, and apoptosis-related B-cell lymphoma 2 and cleaved caspase-3; these alterations were prevented by CTSS deletion. Pharmacological CTSS inhibition mimics its genetic deficiency-mediated muscle benefits. In C2C12 cells, CTSS silencing prevented stressed serum- and oxidative stress-induced IRS-2 protein reduction, loss of the myotube myosin heavy chain content, and apoptosis accompanied by a rectification of investigated molecular harmful changes; these changes were accelerated by CTSS overexpression. These findings demonstrated that CTSS plays a role in IRS-2-related protein anabolism and catabolism and cell apoptosis in stress-induced muscle wasting, suggesting a novel therapeutic strategy for the control of chronic stress-related muscle disease in mice under our experimental conditions by regulating CTSS activity.

Downregulation of desmoglein 2 promotes EMT progression in gallbladder cancer.

OBJECTIVE: To explore the correlation between the expression level of Desmoglein 2 (DSG2) and the epithelial-mesenchymal transition (EMT) progression in gallbladder cancer (GBC). METHOD: 106 GBC tissue specimens and corresponding clinical information were collected to make a tissue microarray. Immunohistochemical method was used to test the expression level of DSG2 in GBC tissues. DSG2 was knocked down in the GBC cell line GBC-SD to detect the change of its invasion and metastasis ability. Then RT-qPCR and Western Blot were applied on the DSG2-knocked down GBC-SD cells to detect the expression level change of genes associated with EMT. RESULT: The high expression rate of DSG2 was significantly correlated with the N, M and TNM staging of patients (P<0.05). Survival analysis identified that GBC patients with high DSG2 expression level had significantly better survival (P<0.05). To further investigate the potential mechanism of DSG2 on regulating GBC tumor progression, we used knockdown DSG2 on GBC-SD cell lines. The results showed that GBC-SD cell lines with DSG2 knockdown showed a promotion of cell invasion and metastatic ability. The mRNA levels of EMT-related genes E-Cadherin, Snail, Twist, ZEB1, and ß-catenin, which is a key protein in the Wnt signaling pathway, were also significantly altered. Besides, protein levels of E-cadherin and Snail showed consistent results. CONCLUSION: The downregulation of DSG2 in gallbladder cancer is hypothesized to be associated with the invasion and metastasis progression of gallbladder cancer cells by regulating EMT-related pathways. Its expression level can be a novel biomarker for gallbladder cancer, providing new perspectives for diagnosis and treatment strategies.

Effect of fasting time before anesthesia on postoperative complications in children undergoing adenotonsillectomy.

OBJECTIVES: Although the guidelines clearly recommend the fasting time of children before anesthesia, it is usually difficult to control. For pediatric patients, prolonged fasting time before surgery will lead to dehydration and hypoglycemia. Adenotonsillectomy is one of the most common operations in pediatric patients, but its complications are not rare. The purpose of this study is to analyze the relationship between preoperative fasting time and postoperative complications in children undergoing adenotonsillectomy. METHODS: The medical and surgical records of 480 pediatric patients who underwent adenotonsillectomy were analyzed retrospectively. They were divided into three groups, including adenoidectomy group, tonsillectomy group, and adenotonsillectomy group. Logistic regression analysis was used to analyze the effect of preoperative fasting time on postoperative complications and hospital stay in pediatric patients of the three groups. RESULTS: The postoperative bleeding rate in the adenoidectomy group (5.16%) was lower than tonsillectomy group and adenoidectomy group (P < .001). Logistic regression analysis showed that the fasting time was positively correlated with the vomiting and pain in adenoidectomy group, tonsillectomy group, and adenotonsillectomy group. And, the postoperative hospital stay was also positively correlated with fasting time in three groups. CONCLUSION: The prolonged fasting time before otolaryngology surgery in children is related to the occurrence of postoperative complications like vomiting and pain, and also to the increase of postoperative hospital stay.

Dipeptidyl peptidase-4 inhibition prevents lung injury in mice under chronic stress via the modulation of oxidative stress and inflammation.

Exposure to chronic psychosocial stress is a risk factor for various pulmonary diseases. In view of the essential role of dipeptidyl peptidase 4 (DPP4) in animal and human lung pathobiology, we investigated the role of DPP4 in stress-related lung injury in mice. Eight-week-old male mice were randomly divided into a non-stress group and a 2-week immobilization stress group. Non-stress control mice were left undisturbed. The mice subjected to immobilized stress were randomly assigned to the vehicle or the DPP4 inhibitor anagliptin for 2 weeks. Chronic stress reduced subcutaneous and inguinal adipose volumes and increased blood DPP4 levels. The stressed mice showed increased levels in the lungs of genes and/or proteins related to oxidative stress (p67phox, p47phox, p22phox and gp91phox), inflammation (monocyte chemoattractant protein-1, vascular cell adhesion molecule-1, and intracellular adhesion molecule-1), apoptosis (caspase-3, -8, -9), senescence (p16INK4A, p21, and p53) and proteolysis (matrix metalloproteinase-2 to -9, cathepsin S/K, and tissue inhibitor of matrix metalloproteinase-1 and -2), and reduced levels of eNOS, Sirt1, and Bcl-2 proteins; and these effects were reversed by genetic and pharmacological inhibitions of DPP4. We then exposed human umbilical vein endothelial cells in vitro to hydrogen peroxide; anagliptin treatment was also observed to mitigate oxidative and inflammatory molecules in this setting. Anagliptin can improve lung injury in stressed mice, possibly by mitigating vascular inflammation, oxidative stress production, and proteolysis. DPP4 may become a new therapeutic target for chronic psychological stress-related lung disease in humans and animals.

Increased dipeptidyl peptidase-4 accelerates chronic stress-related thrombosis in a mouse carotid artery model.

OBJECTIVE: Exposure to chronic psychosocial stress is a risk factor for metabolic cardiovascular disorders. Given that dipeptidyl peptidase-4 (DPP-4) has an important role in human pathobiology, we investigated the role of DPP-4 in stress-related thrombosis in mice, focusing on oxidative stress and the von Willebrand factor (vWF)-cleaving protease ADAMTS13 (a disintegrin and metalloproteinase with thrombospondin type 1 motif, member 13). METHODS AND RESULTS: Male mice randomly assigned to nonstress and 2-week immobilized-stress groups underwent iron chloride3 (FeCl3)-induced carotid artery thrombosis surgery for morphological and biochemical studies at specific times. On day 14 post-stress/surgery, stress had enhanced the lengths and weights of arterial thrombi, with alterations of plasma DPP-4, plasminogen activation inhibitor-1 and ADAMTS13. The stressed mice had increased levels of vascular cell adhesion molecule-1, intracellular adhesion molecule-1, monocyte chemoattractant protein-1, gp91phox, p22phox, matrix metalloproteinase-2 (MMP-2), MMP-9, cathepsins S and K mRNAs and/or proteins, and reduced levels of endothelial nitric oxide synthase, catalase and superoxide dismutase-1 mRNAs and/or proteins. Stress also accelerated arterial endothelial cell damage. The DPP-4 inhibitor anagliptin ameliorated the stress-induced targeted molecular and morphological changes and thrombosis. In vitro, DPP-4 inhibition also mitigated the alterations in the targeted ADAMTS13 and other oxidative and inflammatory molecules in human umbilical vein endothelial cells in response to H2O2. CONCLUSION: DPP-4 inhibition appeared to improve the FeCl3-induced thrombosis in mice that received stress, possibly via the improvement of ADAMTS13 and oxidative stress, suggesting that DPP-4 could become a novel therapeutic target for chronic psychological stress-related thrombotic events in metabolic cardiovascular disorders.

Dipeptidyl peptidase-4 inhibition prevents vascular aging in mice under chronic stress: Modulation of oxidative stress and inflammation.

BACKGROUND AND AIMS: Chronic psychosocial stress is a risk factor for cardiovascular disease. In view of the important role of dipeptidyl peptidase-4 (DPP-4) in human pathophysiology, we studied the role of DPP-4 in stress-related vascular aging in mice, focusing on oxidative stress and the inflammatory response. METHODS AND RESULTS: Male mice were randomly divided into a non-stress group and an immobilization stress group treated for 2 weeks. Chronic stress accelerates aortic senescence and increases plasma DPP-4 levels. Stress increased the levels of gp91phox, p22phox, p47phox, p67phox, p53, p27, p21, p16INK4A, vascular cell adhesion molecule-1, intracellular adhesion molecule-1, monocyte chemoattractant protein-1, matrix metalloproteinase-2 (MMP-2), MMP-9, cathepsin S (Cat S), and Cat K mRNAs and/or protein in the aorta of the stressed mice and decreased their levels of endothelial nitric oxide synthase and SirTuin1 (SirT1). DPP-4 inhibitors can improve stress-induced targeting molecules and morphological changes. In vitro, the inhibition of DPP-4 also alleviated the changes in the oxidative and inflammatory molecules in response to hydrogen peroxide in human umbilical vein endothelial cells. CONCLUSIONS: DPP-4 inhibition can improve vascular aging in stressed mice, possibly by improving oxidative stress production and vascular inflammation. Our results suggest that DPP-4 may become a new therapeutic target for chronic stress-related vascular aging in metabolic cardiovascular diseases.

Adiponectin/AdiopR1 signal inactivation contributes to impaired angiogenesis in mice of advanced age.

BACKGROUND: The mechanism by which angiogenesis declines with aging remains largely unknown. Given that the plasma levels of adiponectin (APN) are decreased in the presence of ischemic cardiovascular disease, we explore the possible mechanisms by which APN/adiponectin receptor1 (AdipoR1) axis inactivation contributes to the decline in vascular regeneration capacity in elderly animals. METHODS AND RESULTS: To study aging-related changes in the APN/AdipoR1 axis and its impact on ischemia-induced angiogenesis, a hindlimb ischemia model was applied to young and aged mice. Aging impaired ischemia-induced blood flow recovery. An ELISA showed that the aged mice had decreased plasma APN levels. Immunostaining showed lesser capillary formation in the aged mice. The aged ischemic muscles had decreased levels of AdipoR1, peroxisome proliferator activated receptor-γ (PPAR-γ), PPAR-γ co-activator 1α (PGC-1α), phospho-AMP-activated protein kinase α (p-AMPK-α), and B cell lymphoma-2 (Bcl-2) and increased levels of cleaved caspase-8 (C-caspase-8) and gp91phox/p22phox genes or/and proteins, nicotinamide adenine dinucleotide phosphate oxidase activity, superoxide production, and matrix metalloproteinase-2/-9 activity as well as increased numbers of infiltrated macrophages and leucocytes. In in vitro experiments, aged endothelial cells had negative changes in the levels of PPAR-γ, PGC-1α, p-AMPK-α, Bcl-2, and C-caspase-8 proteins in response to oxidative stress. Genetic interventions targeted toward APN and AdipoR1 negatively affected the targeted angiogenic protein levels in aged muscles and angiogenic actions and/or aged endothelial events. CONCLUSION: These findings indicate that aging can reduce angiogenesis in response to hypoxia via an impaired APN-AdipoR1-dependent mechanism that may be mediated by PPAR-γ/PGC-1α signaling inactivation in advanced age.

High Omega-3 Polyunsaturated Fatty Acids in fat-1 Mice Reduce Inflammatory Pain.

Omega-3 and omega-6 polyunsaturated fatty acids (PUFAs), such as α-linolenic and linoleic acids, are essential fatty acids in mammals, because they cannot be synthesized de novo. However, fat-1 transgenic mice can synthesize omega-3 PUFAs from omega-6 PUFAs without dietary supplementation of omega-3, leading to abundant omega-3 PUFA accumulation in various tissues. In this study, we used fat-1 transgenic mice to investigate the role of omega-3 PUFAs in response to inflammatory pain. A high omega-3 PUFA tissue content attenuated formalin-induced pain sensitivity, microglial activation, inducible nitric oxide synthase expression, and the phosphorylation of NR2B, a subunit of the N-methyl-d-aspartate (NMDA) receptor. Our findings suggest that elevated omega-3 PUFA levels inhibit NMDA receptor activity in the spinal dorsal horn and modulate inflammatory pain transmission by regulating signal transmission at the spinal dorsal horn, leading to the attenuation of chemically induced inflammatory pain.

Expression of granulocyte colony-stimulating factor 3 receptor in the spinal dorsal horn following spinal nerve ligation-induced neuropathic pain.

In previous studies that have profiled gene expression in patients with complex regional pain syndrome (CRPS), the expression of granulocyte colony-stimulating factor 3 receptor (G­CSFR) was elevated, as were a number of pain­associated genes. The present study determined the expression of G­CSFR and the mechanisms by which it may affect hypersensitivity, focusing on the signal transducer and activator of transcription 3 (STAT3)/transient receptor potential cation channel subfamily V 1 (TRPV1) signaling pathway in particular, which is an important mediator of pain. Following L5 spinal nerve ligation (SNL) surgery, the protein and mRNA levels of G­CSFR increased in the ipsilateral spinal dorsal horn when compared with the sham and/or contralateral control. Double immunofluorescence further demonstrated that G­CSFR colocalized with TRPV1 and phosphorylated STAT in the neurons of the spinal dorsal horn. G­CSF treatment led to an increase in G­CSFR and TRPV1 expression and phosphorylation of STAT3. These results indicate that G­CSF­induced G­CSFR expression may activate TRPV1 by promoting phosphorylation of STAT3. Collectively, the results suggest, for the first time, that the expression of G­CSFR in neurons following peripheral nerve injury may be involved in the induction and maintenance of neuropathic pain through the STAT3 and TRPV1 signaling pathway.

Association between omentin and echo parameters in patients with chronic heart failure.

BACKGROUND: Adipose-derived adipokines have been demonstrated to be associated with the development of experimental heart disease through chronic inflammation and cardiac cell apoptosis. Omentin is to be one of the novel adipokines. The aim of this study is to investigate the relationship between circulating omentin and cardiac dysfunction in patients with chronic heart failure (CHF). METHODS: A total of 189 CHF patients were studied, determining serum omentin and echocardiographic parameters. All participants were divided into two experimental groups: the 111 patients who had a left ventricular ejection fraction (EF) ≥40% (EF-H) and the 78 patients exhibiting EF values <40% (EF-L). RESULTS: The EF-L group showed significantly higher circulating omentin levels compared to the EF-H group (210.8±67.2 vs. 155.3±45.3, P<0.001; Student's t-test). Overall, the data of the linear regression analysis revealed that serum omentin levels correlated positively with left atrial diameters (r=0.31, P=0.006), left ventricular end-systolic dimensions (r=0.42, P<0.001), and left ventricular end-diastolic dimensions (r=0.38, P=0.002) and negatively with left ventricular EF (r=-0.45, P=0.001; Spearmen's rank correlations coefficients for each). The multiple regression model included all variables at p<0.1 by the univariate analysis. A multiple logistic regression analysis demonstrated that high levels of patients' serum omentin were associated with cardiac dysfunction in patients with CHF (OR=1.22; 95% CI: 0.91-1.58; P=0.009). CONCLUSIONS: These findings suggested that elevated serum omentin levels were only very mildly related to the changes in cardiac volume and function in CHF patients. Further studies are then needed to assess the real clinical value of omentin in this setting.

Increased Circulating Cathepsin K in Patients with Chronic Heart Failure.

Cysteinyl cathepsin K (CatK) is one of the most potent mammalian collagenases involved in cardiovascular disease. Here, we investigated the clinical predictive value of serum CatK levels in patients with chronic heart failure (CHF). We examined 134 patients with CHF, measuring their serum CatK, troponin I, high-sensitive C-reactive protein, and pre-operative N-terminal pro-brain natriuretic peptide levels. The patients were divided into two groups: the 44 patients who showed a left ventricular (LV) ejection fraction (LVEF) < 40% (the "lowLVEF" group) and the 90 patients showing LVEF values ≥ 40% (the "highLVEF" group). The lowLVEF patients had significantly higher serum CatK levels compared to the highLVEF patients (58.4 ± 12.2 vs. 44.7 ± 16.4, P < 0.001). Overall, a linear regression analysis showed that CatK levels correlated negatively with LVEF (r = -0.4, P < 0.001) and positively with LV end-diastolic dimensions (r = 0.2, P < 0.01), LV end-systolic dimensions (r = 0.3, P < 0.001), and left atrial diameters (r = 0.3, P < 0.01). A multiple logistic regression analysis showed that CatK levels were independent predictors of CHF (odds ratio, 0.90; 95% confidence interval, 0.84-0.95; P < 0.01). These data indicate that elevated levels of CatK are closely associated with the presence of CHF and that the measurement of circulating CatK provides a noninvasive method of documenting and monitoring the extent of cardiac remodeling and dysfunction in patients with CHF.

Increased serum cathepsin K in patients with coronary artery disease.

PURPOSE: Cathepsin K is a potent collagenase implicated in human and animal atherosclerosis-based vascular remodeling. This study examined the hypothesis that serum CatK is associated with the prevalence of coronary artery disease (CAD). MATERIALS AND METHODS: Between January 2011 and December 2012, 256 consecutive subjects were enrolled from among patients who underwent coronary angiography and percutaneous coronary intervention treatment. A total of 129 age-matched subjects served as controls. RESULTS: The subjects' serum cathepsin K and high sensitive C-reactive protein (hs-CRP) and high-density lipoprotein cholesterol were measured. The patients with CAD had significantly higher serum cathepsin K levels compared to the controls (130.8±25.5 ng/mL vs. 86.9±25.5 ng/mL, p<0.001), and the patients with acute coronary syndrome had significantly higher serum cathepsin K levels compared to those with stable angina pectoris (137.1±26.9 ng/mL vs. 102.6±12.9 ng/mL, p<0.001). A linear regression analysis showed that overall, the cathepsin K levels were inversely correlated with the high-density lipoprotein levels (r=-0.29, p<0.01) and positively with hs-CRP levels (r=0.32, p<0.01). Multiple logistic regression analyses shows that cathepsin K levels were independent predictors of CAD (odds ratio, 1.76; 95% confidence interval, 1.12 to 1.56; p<0.01). CONCLUSION: These data indicated that elevated levels of cathepsin K are closely associated with the presence of CAD and that circulating cathepsin K serves a useful biomarker for CAD.

Impaired cross-activation of ß3 integrin and VEGFR-2 on endothelial progenitor cells with aging decreases angiogenesis in response to hypoxia.

BACKGROUND: The mechanism by which vascular regeneration declines with aging is not fully understood. An interaction between integrin and vascular endothelial growth factor receptor-2 (VEGFR-2) plays a substantial role in angiogenesis. Here, we investigated whether aging impairs this interaction in endothelial progenitor cells (EPCs) under hypoxia. METHODS AND RESULTS: Aging reduced the blood flow and vessel density in ischemic muscles in mice. Levels of phosphorylated Src (p-Src), p-ß3, and p-VEGFR-2 in acute ischemia were reduced in the muscles of aged mice compared to young mice. The hypoxia-inducible factor (HIF)-1α stabilizer deferoxamine improved the age-related impairment of angiogenesis, but this effect was diminished by LY290004, an inhibitor of phosphatidylinositol 3-kinase. Deferoxamine improved the reduction in chronic ischemia-induced ß3-integrin and VEGFR-2 phosphorylation in the muscles of aged mice; this effect was also diminished by LY290004. In EPCs, we identified the molecular requirements for VEGF-mediated ß3-integrin and VEGFR-2 cross-activation in vitronectin-induced cell adhesion under acute hypoxia. We demonstrated that c-Src controlled the adhesion- and VEGF-induced ß3 tyrosine phosphorylation in hypoxia. Aging enhanced the hypoxia-induced EPC apoptosis and impaired several c-Src-related VEGF-induced receptor events, including ß3 tyrosine activation, ligand binding, cell adhesion, and tubulogenesis in cultured EPCs of animals and those of humans. CONCLUSIONS: These data suggest that the aging-related decline in angiogenic action in response to ischemia is mediated by the impairment of cross-activation between ß3 and VEGFR-2 in EPCs, which is partially associated with decreased HIF-1α stability.

Opposing effects of isoflurane and sevoflurane on neurogenic pulmonary edema development in an animal model.

BACKGROUND: The current study was undertaken to investigate the effects of pretreatment with isoflurane and sevoflurane on the development of neurogenic pulmonary edema in an animal model. METHODS: Rats were exposed to room air (control), 1.5% isoflurane, or 2.5% sevoflurane for 4 h. They were then anesthetized with intraperitoneal injections of pentobarbital sodium, and fibrinogen and thrombin were injected into the cisterna magna to induce neurogenic pulmonary edema. RESULTS: Consecutive injections of fibrinogen and thrombin caused increases in blood pressure, with the peak values obtained in the isoflurane and sevoflurane groups being lower than the control values. The incidence of significant neurogenic pulmonary edema was 58%, 100%, and 8% in the control, isoflurane, and sevoflurane groups, respectively. The lung water ratio, an index of severity of edema, was 4.86 +/- 0.78, 6.15 +/- 0.64, and 4.40 +/- 0.32 in the control, isoflurane, and sevoflurane groups, respectively. Furthermore, immunohistochemical staining for vascular endothelial growth factor demonstrated an increase of expression in the rat lungs exposed to isoflurane. Treatment with an anti-vascular endothelial growth factor antibody during exposure to isoflurane completely inhibited the effect of isoflurane to promote neurogenic pulmonary edema in this model. CONCLUSION: Exposure to 1.5% isoflurane enhances the development of neurogenic pulmonary edema development in this animal model, most likely via release of vascular endothelial growth factor from bronchial epithelial cells, an effect not observed with sevoflurane.

Effects of specific signal transduction inhibitors on increased permeability across rat endothelial monolayers induced by neuropeptide Y or VEGF.

Neuropeptide Y (NPY) elevates the permeability of cultured rat aortic endothelial cells (RAECs) in monolayer cultures under hypoxic conditions (5% O(2)) possibly by binding to the NPY Y(3) receptor. The present study evaluated the effects of NPY compared to vascular endothelial growth factor (VEGF). RAECs were cultured on the upper chamber base of a double-chamber culture system, FITC-labeled albumin was introduced into the chamber, and permeation into the lower chamber was measured. Treatment was with 3 x 10(-7) M NPY or 10(-7) g/ml VEGF for 2 h along with specific inhibitors. The VEGF receptor-2 tyrosine kinase inhibitor tyrphostin SU-1498 and the protein kinase C inhibitor bis-indolylmaleimide I (GF-109203X) suppressed the VEGF-induced increase in monolayer permeability but not that caused by NPY. Furthermore, although the action of NPY was blocked in a concentration-dependent manner by phospholipase C inhibitor 1-(6-[[(17beta)-3-methoxyestra-1,3,5(10)-trien-17-yl]amino]hexyl)-1H-pyrrole-2,5-dione (U-73122), it was less sensitive than VEGF. However, the effects of both NPY and VEGF on the permeability of the RAEC monolayer were blocked with equal concentration dependence by STI571 (imatinib mesylate), which is an inhibitor of Abl tyrosine kinase in the nucleus and/or cytoplasm. The myosin light-chain kinase inhibitor 1-(5-chloronaphthalene-1-sulfonyl)-1H-hexahydro-1,4-diazepine HCl (ML-9) suppressed both NPY- and VEGF-induced increment in permeability by approximately 70%, whereas the calmodulin-dependent kinase inhibitor DY-9760e could decrease to below the baseline. These results indicate that the NPY Y(3)-receptor subtype is specifically linked to the effects of STI571 on endothelial cells, and that NPY, a sympathetic coneurotransmitter, may increase vascular permeability in association with altered intracellular or nuclear signal transduction.

Neuropeptide Y enhances permeability across a rat aortic endothelial cell monolayer.

Previously, in vivo studies showed that neuropeptide Y (NPY) elevates vascular permeability in isolated lung perfusion preparations, possibly through binding to the NPY Y(3) receptor. The present study used monolayers in a double-chamber culture method under conditions of normoxia (5% CO(2)-20% O(2)-75% N(2)) or hypoxia (5% CO(2)-5% O(2)-90% N(2)) to test the hypothesis that NPY directly affects rat aortic endothelial cells (RAECs). RAECs were cultured on the base of the upper chamber, into which FITC-labeled albumin was introduced, and permeation into the lower chamber was measured. The RAEC monolayer was treated with 10(-8)-3 x 10(-7) M NPY for 2 h in normoxia or hypoxia. In hypoxia, NPY concentration dependently increased the permeability of the RAEC monolayer, whereas in normoxia no significant change was observed. Peptide YY, NPY Y(1), and NPY Y(2) receptor agonists and NPY Y(1) receptor antagonist exerted no significant effects under hypoxic conditions. NPY-(18-36), an NPY Y(3) receptor antagonist, elicited an inhibitory action on the NPY-induced increase in monolayer permeability. Furthermore, neither N-monomethyl-l-arginine, a nitric oxide synthase inhibitor, the bradykinin B(2) receptor antagonist FK-3657, nor the vascular endothelial growth factor receptor-coupled tyrosine kinase inhibitor tyrphostin SU-1498, injected into the medium of the upper chamber, affected the NPY-induced permeability changes under hypoxic conditions. The results suggest that the NPY-induced increase in permeability across the RAEC monolayer is closely related to low O(2) tension, possibly mediated by direct action on the NPY Y(3) receptor expressed on the endothelial cell membrane. Furthermore, this NPY-induced increase is not likely due to nitric oxide, bradykinin, or vascular endothelial growth factor.