AIMTo investigate the effects of endothelin-1 (ET-1) and nitric oxide (NO) on lipopolysaccharide(LPS)-induced myocardial dysfunction, and explore the related underlying mechanisms.

METHODSExperimental septic model was established by intraperitoneal injection of LPS (10 mg x kg(-1)). The study was carried out on the isolated rat hearts to determine the roles of ET-1 and NO in the effect of LPS on the cardiac contractility and on the isolated rat ventricular myocytes model to observe the [Ca2+]i homeostasis in cardiac myocytes.

RESULTS(1) The levels of serum NO2-/NO3- and plasma ET-1 were markedly increased by LPS treatment for 4 hours. (2) LPS induced the decrease in rate-pressure product (RPP), and increase in left ventricular end-diastolic pressure (LVEDP) in the isolated perfused rat hearts. Pretreatment with either aminoguanidine (AMG) (100 mg x kg(-1), i.p.) or BQ-123 (1 mg x kg(-1), i.p.) partially attenuated LPS-induced myocardial depression. When these two drugs were simultaneously given, myocardial depression elicited by LPS was almost abolished. (3) LPS significantly decreased the amplitude of caffeine induced [Ca2+]i transients compared to the control cells. The activity of SR Ca22+ -ATPase was significantly decreased in the cardiac myocytes from LPS-treated rats. Single pretreatment with either AMG or BQ-123 did not attenuate the impairment of SR Ca2+ -ATPase induced by LPS.

CONCLUSIONET-1 and NO mediate myocardial dysfunction in hearts isolated and decrease [Ca2+]i transients in cardiac myocytes from LPS-treated rats. But neither ET-1 nor NO participates in the impairment of SR Ca2+ -ATPase induced by LPS.

Animals ; Depression, Chemical ; Endothelin-1 ; physiology ; Lipopolysaccharides ; toxicity ; Male ; Myocardial Contraction ; drug effects ; physiology ; Nitric Oxide ; physiology ; Rats ; Rats, Sprague-Dawley ; Shock, Septic ; chemically induced ; physiopathology

The effects of endothelin-1 (ET-1) at low concentration (1-100 pmol/L) on the reactive oxygen-induced inhibition of both pulmonary surfactant (PS) lipid synthesis and the activity of CTP: phosphorylcholine cytidylyltransferase (CCT), a rate-limiting enzyme in biosynthesis of phosphoatidylcholine (PC), were studied in cultured lung explants without serum. The xanthine-xanthine oxidase superoxide anion generating system decreased (3)H-choline incorporation into PC in a dose-dependent manner in cultured lung explants. ET-1 reduced both the reactive oxygen-induced decrease in (3)H-choline incorporation and the increase in malondialdehyde (MDA) content of lung tissues, but did not change the levels of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) and the total antioxidant capability in the lung explants. ET-1 enhanced microsomal CCT activity of the lung tissues, while it decreased cytosolic CCT activity of lung tissues. ET-1 also prevented the inhibitive effect of reactive oxygen on microsomal CCT activity in the lung explants. These results suggest that ET-1 at low concentration can protect the microsomal CCT activity and reduce the inhibition of PS lipid synthesis induced by oxidant lung injury. The protective mechanism of ET-1 is not relative to the pulmonary endogenous antioxidant defense system.
Animals ; Choline-Phosphate Cytidylyltransferase ; metabolism ; Endothelin-1 ; administration & dosage ; pharmacology ; Female ; In Vitro Techniques ; Lung ; drug effects ; enzymology ; metabolism ; Male ; Phospholipids ; biosynthesis ; Pulmonary Surfactants ; chemistry ; Rats ; Rats, Wistar ; Reactive Oxygen Species ; toxicity

OBJECTIVETo assess the role of vanilloid receptor (VR) in thermal hyperalgesia induced by intraplantar endothelin-1 (ET-1) injection.

METHODSVR gene-knockout mice (KO group) and wild type C57BL/6J mice (WT group) in 3 subgroups were subjected to intraplantar administration of ET-1 at the doses of 3, 10, 30 and 100 pmol (dissolved in 10 microl of PBS, pH 7.4, n=6 in each group), respectively. The latency time of paw withdrawal (PWT) from heat irradiation stimulation was recorded before injection and 15, 30, 45 and 60 min after injection.

RESULTSET-1 induced thermal hyperalgesia in both groups. The mice in WT group showed a more sharply shortened PWT than those in KO group. ET-1 decreased PWT as the dose administered increased in WT group, which was different from the responses of the KO mice. At the dose of 100 pmol of ET-1, no further decrement of latency time was observed in WT group, whereas such response occurred at 30 pmol in KO group.

CONCLUSIONIntraplantar injection of ET-1 induces thermal hyperalgesia mediated partially by VR.

Animals ; Dose-Response Relationship, Drug ; Endothelin-1 ; administration & dosage ; toxicity ; Genotype ; Hot Temperature ; Hyperalgesia ; chemically induced ; physiopathology ; Male ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; Pain Measurement ; methods ; TRPV Cation Channels ; genetics ; physiology

BACKGROUNDEpithelial dysfunction in lungs plays a key role in the pathogenesis of acute lung injury. The beneficial effects of low potassium dextran glucose solution (LPD) have been reported in lung preservation, and LPD enables injured alveolar pneumocytes to recover. So we hypothesized that systemic administration of LPD may have benefits in treating acute lung injury. We investigated the effects of LPD on arterial blood gas and levels of some cytokines in oleic acid-induced acute lung injury in juvenile piglets.

METHODSOleic acid (0.1 ml/kg) was intrapulmonarily administered to healthy anesthetized juvenile piglets. Ten animals were randomly assigned to two groups (n = 5 each): oleic acid-induced group (control group) with intravenous infusion of 12.5 ml/kg of lactated Ringer's solution 30 minutes before administration of oleic acid and LPD group with systemic administration of LPD (12.5 ml/kg) 30 minutes before injecting oleic acid. Blood gas variables and concentrations of tumor necrosis factor alpha, endothelin 1 and interleukin 10 were measured before and every 1 hour for 6 hours after initial lung injury.

RESULTSCompared with control group, blood pH, partial pressure of arterial oxygen to fraction of inspired oxygen ratio, partial pressure of arterial carbon dioxide, and mean pulmonary arterial pressure in LPD group were improved (P < 0.05 or 0.01). Six hours after lung injury, concentration of tumor necrosis factor alpha in lung tissue was lower in LPD group than control group (P < 0.05). Plasmic concentration of endothelin 1 showed lower in LPD group while plasmic concentration of interleukin 10 showed higher in LPD group (P < 0.05).

CONCLUSIONSBefore lung injury, systemic administration of LPD can improve gas exchange, attenuate pulmonary hypertension, decrease plasmic levels of endothelin 1, increase interleukin 10 and decrease concentration of tumor necrosis factor alpha in lung tissue in oleic acid-induced acute lung injury in juvenile piglets.

Acute Lung Injury ; blood ; chemically induced ; drug therapy ; Animals ; Dextrans ; therapeutic use ; Endothelin-1 ; blood ; Female ; Glucose ; therapeutic use ; Interleukin-10 ; blood ; Male ; Oleic Acid ; toxicity ; Swine ; Tumor Necrosis Factor-alpha ; blood

OBJECTIVETo observe the phenomenon of pulmonary hemorrhage (PH) induced by exogenous endothelin-1 (exET-1) and the antagonizing effect of exogenous calcitonin gene-related peptide (exCGRP) in newborn rats.

METHODS(1) To study the exET-1 induced PH: 100 newborn Wistar rats were randomly assigned into control group (group A, n = 10) and experiment groups (20 rats in each of groups B, C, D and E and 10 in group F). Thirty microl of normal saline and different concentrations of exET-1 in saline (ranged from 2 x 10(-6) mol/L to 10 x 10(-6) mol/L) were dripped into the rats' trachea through intubation for control group and the experiment groups, respectively. (2) To study the antagonizing effect of calcitonin gene-related peptide against endothelin: 50 rats were randomly assigned into control group (group D(1), n = 10) and experiment groups D(2), D(3), D(4) and D(5) (10 rats in each group), and were treated with 30 microl of normal saline as control and 4 x 10(-6) mol/L exET-1 via tracheal dripping. Twenty microl of exCGRP (concentrations ranged from 6.7 x 10(-8) mol/L to 6.7 x 10(-6) mol/L) were given by dripping to rats in groups D(3) to D(5) 30 minutes after the administration of exET-1. (3) The rats were sacrificed 3 hours after the first tracheal dripping and the gross anatomical and histological (HE staining) changes in lungs were observed.

RESULTS(1) Following the treatment with exET-1, the rats showed cyanosis and dyspnea rapidly. The severity of respiratory symptoms varied in a dose dependent fashion with the concentrations of exET-1. The symptoms were relieved in the survived rats in about 30 minutes. The rats of all exET-1 treated groups presented with different degree of PH and group D (treated with 4 x 10(-6) mol/L of exET-1) had the highest incidence (diffuse PH 30%, focal PH 25%, spotty PH 25% and 80% in total), with a mortality of 20%. Rats in group E and F had lower incidence of PH (50% and 20%) but higher mortality (35% and 60%). (2) After the administration of different concentrations of exCGRP, the skin of the exET-1 treated rats turned ruddy rapidly with a significantly decreased incidence of PH and all the rats survived. The best protective effect was observed with the concentration of 6.7 x 10(-6) mol/L, and the incidence of PH was reduced to 20% (focal PH 10%, spotty PH 10%).

CONCLUSIONA significant increase of the endogenous ET-1 in hemorrhagic lung tissue caused by rewarming and reoxygenation following hypothermia and hypoxia had been confirmed. Administration of intratracheal exET-1 could induce pulmonary hemorrhage. This suggests that a significant increase of endogenous ET-1 in lung tissue may be one of the mechanisms in pathogenesis of PH caused by rewarming and reoxygenation following hypothermia and hypoxia. Endotracheal administration of exCGRP showed protective antagonizing effect against PH induced by exET-1. The authors speculate that the exCGRP has the potential to treat or even prevent PH caused by a significant increase of the endogenous ET-1.

Animals ; Animals, Newborn ; Calcitonin Gene-Related Peptide ; pharmacology ; Dose-Response Relationship, Drug ; Endothelin-1 ; toxicity ; Female ; Hemorrhage ; chemically induced ; prevention & control ; Lung ; drug effects ; pathology ; Lung Diseases ; chemically induced ; prevention & control ; Male ; Random Allocation ; Rats ; Rats, Wistar

OBJECTIVE: To investigate the vascular damage effects and possible mechanism of acute exposure to ozone (O) in male Wistar rats. METHODS: One hundred and twenty male Wistar rats were randomly divided into six groups, 20 in each group. The experimental animals were placed in a gas poisoning cabinet, the control group was exposed to filtered air, and the treatment group was exposed to ozone at concentrations of 0.12 ppm, 0.5 ppm, 1.0 ppm, 2.0 ppm, and 4.0 ppm, respectively, for 4 hours. Arterial blood pressure data were obtained by PC-lab medical physiological signal acquisition system. Blood rheology indicators and blood biochemical indicators were detected by Tianjin Dean Diagnostic Laboratory. Serum endothelin-1 (ET-1), homocysteine (HCY), von Willebrand factor (vWF), 8-hydroxydeoxyguanosine (8-OhdG), interleukin (IL-6) and tumor necrosis factor alpha (TNF-α) were detected by enzyme-linked immunosorbent assay (ELISA) microplate assay. Oxidative stress indicators superoxide dismutase (SOD) activity and malondialdehyde (MDA) were determined by xanthine oxidase method, thiobarbituric acid (TBA) method, reduced glutathione (GSH) and nitric oxide (NO) were tested by using microplate colorimetry. Paraffin sections were prepared from thoracic aorta tissue, and vascular structure was observed by HE staining. RESULTS: Acute exposure to 0.12 ppm ozone could cause a significant increase in arterial systolic blood pressure (SBP). Exposure to different concentrations of ozone could cause a significant increase in plasma viscosity, and the K value of the ESR equation was significantly increased in the 1.0 ppm ozone exposure group. Both the relative and reduced viscosities were significantly reduced at ozone concentrations of 0.5 ppm and 4.0 ppm, while the red blood cell deformation index was increased significantly at ozone concentrations of 0.12 ppm, 0.5 ppm, 1.0 ppm, and 2.0 ppm. Acute ozone exposure resulted in the decrease of total cholesterol content. The content of high-density lipoprotein cholesterol (HDL-C) was significantly reduced in the 0.12 ppm ozone exposure group. When the ozone concentration was higher than 1.0 ppm, the body may also had an inflammatory reaction (increased TNF-α) and oxidative stress (increased MDA, decreased GSH). Acute exposure to ozone could lead to elevated levels of ET-1 in the blood, with significant differences in the 4.0 ppm concentration group, while HCY levels were decreased firstly and then increased, reaching the highest in the 1.0 ppm concentration group. No obvious pathological changes were observed in the thoracic aorta. CONCLUSION Acute ozone exposure can affect arterial blood pressure, blood rheology and cholesterol metabolism in rats. The possible mechanism is that ozone exposure leads to inflammatory reaction and oxidative stress reaction, causing vascular endothelial function damage, and vascular endothelial cells increase with ozone exposure concentration.
Animals ; Blood Vessels ; injuries ; Deoxyguanosine ; analogs & derivatives ; blood ; Endothelin-1 ; blood ; Homocysteine ; blood ; Interleukin-6 ; blood ; Male ; Malondialdehyde ; analysis ; Oxidative Stress ; Ozone ; toxicity ; Rats ; Rats, Wistar ; Superoxide Dismutase ; analysis ; Tumor Necrosis Factor-alpha ; blood ; von Willebrand Factor ; analysis

Pulmonary arterial hypertension (PAH) causes right ventricular failure due to a gradual increase in pulmonary vascular resistance. The purposes of this study were to confirm the engraftment of human umbilical cord blood-mesenchymal stem cells (hUCB-MSCs) placed in the correct place in the lung and research on changes of hemodynamics, pulmonary pathology, immunomodulation and several gene expressions in monocrotaline (MCT)-induced PAH rat models after hUCB-MSCs transfusion. The rats were grouped as follows: the control (C) group; the M group (MCT 60 mg/kg); the U group (hUCB-MSCs transfusion). They received transfusions via the external jugular vein a week after MCT injection. The mean right ventricular pressure (RVP) was significantly reduced in the U group after the 2 week. The indicators of RV hypertrophy were significantly reduced in the U group at week 4. Reduced medial wall thickness in the pulmonary arteriole was noted in the U group at week 4. Reduced number of intra-acinar muscular pulmonary arteries was observed in the U group after 2 week. Protein expressions such as endothelin (ET)-1, endothelin receptor A (ERA), endothelial nitric oxide synthase (eNOS) and matrix metalloproteinase (MMP)-2 significantly decreased at week 4. The decreased levels of ERA, eNOS and MMP-2 immunoreactivity were noted by immnohistochemical staining. After hUCB-MSCs were administered, there were the improvement of RVH and mean RVP. Reductions in several protein expressions and immunomodulation were also detected. It is suggested that hUCB-MSCs may be a promising therapeutic option for PAH.
Animals ; Cytokines/metabolism ; Disease Models, Animal ; Endothelin-1/metabolism ; Fetal Blood/*cytology ; Gene Expression Regulation/drug effects ; Hemodynamics ; Humans ; Hypertension, Pulmonary/chemically induced/*therapy ; Hypertrophy, Right Ventricular/physiopathology ; Immunohistochemistry ; Lung/metabolism/pathology ; Male ; Matrix Metalloproteinase 2/metabolism ; *Mesenchymal Stem Cell Transplantation ; Mesenchymal Stromal Cells/*cytology/metabolism ; Monocrotaline/toxicity ; Nitric Oxide Synthase Type III/metabolism ; Pulmonary Artery/pathology ; Rats ; Rats, Sprague-Dawley ; Receptor, Endothelin A/metabolism

Although 4,4'-diaminodiphenylsulfone (DDS, dapsone) has been used to treat several dermatologic conditions, including Hansen disease, for the past several decades, its mode of action has remained a topic of debate. We recently reported that DDS treatment significantly extends the lifespan of the nematode C. elegans by decreasing the generation of reactive oxygen species. Additionally, in in vitro experiments using non-phagocytic human fibroblasts, we found that DDS effectively counteracted the toxicity of paraquat (PQ). In the present study, we extended our work to test the protective effect of DDS against PQ in vivo using a mouse lung injury model. Oral administration of DDS to mice significantly attenuated the lung tissue damage caused by subsequent administration of PQ. Moreover, DDS reduced the local expression of mRNA transcripts encoding inflammation-related molecules, including endothelin-1 (ET-1), macrophage inflammatory protein-1alpha (MIP-1alpha), and transforming growth factor-beta (TGF-beta). In addition, DDS decreased the PQ-induced expression of NADPH oxidase mRNA and activation of protein kinase Cmicro (PKCmicro). DDS treatment also decreased the PQ-induced generation of superoxide anions in mouse lung fibroblasts. Taken together, these data suggest the novel efficacy of DDS as an effective protective agent against oxidative stress-induced tissue damages.
Animals ; Cells, Cultured ; Chemokine CCL3/drug effects/metabolism ; Dapsone/*administration & dosage ; Endothelin-1/drug effects/metabolism ; Fibroblasts/drug effects ; Herbicides/*antagonists & inhibitors/toxicity ; Lung Injury/chemically induced/*prevention & control ; Male ; Mice ; Mice, Inbred BALB C ; Oxidative Stress ; Paraquat/*antagonists & inhibitors/toxicity ; Protective Agents/*administration & dosage ; Protein Kinase C/genetics/metabolism ; Superoxides/analysis ; Transforming Growth Factor beta/drug effects/metabolism

The purpose of this study was to evaluate the neuroprotective effect of memantine, a N-methyl-D-aspartate antagonist, in an experimental optic nerve ischemia. Endothelin-1 (ET-1) in a dosage of 0.1 microg/day was delivered to the perineural region of the anterior optic nerve by osmotically driven minipumps for 8 weeks in 10 rabbits. In 5 rabbits, 1 mg/kg memantine was administered concurrently by intramuscular injection once a daily. Morphologic optic nerve head changes were monitored with a confocal scanning laser ophthalmoscope. Multivariate statistical analysis showed a significant change in topometric parameters (cup area, cup depth and rim volume), indicating an increase in optic nerve head cupping and a decrease of neural rim volume in the ET-1 administered eyes (P < 0.0001). In rabbits where memantine was given concurrently with ET-1, no significant change in topometric parameters was observed after ET-1 administration (P = 0.78). The current results suggest that memantine has a neuroprotective effect in optic nerve ischemia. Memantine may potentially be useful in the management of various ischemic disorders of the optic nerve, including glaucoma.
Animal ; Comparative Study ; Endothelin-1/toxicity ; Excitatory Amino Acid Antagonists/*therapeutic use ; Male ; Memantine/*therapeutic use ; Models, Animal ; Neuroprotective Agents/*therapeutic use ; Optic Disk/*drug effects/pathology ; Optic Nerve/*drug effects/pathology ; Optic Neuropathy, Ischemic/chemically induced/pathology/*prevention & control ; Rabbits