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Chinese scientists have been actively engaged in biotechnology research since the mid-20th century. However, biotechnology education, especially biomedical laboratory technology education, is relatively scarce in China. More and more cutting-edge equipment and techniques have been introduced into biomedical laboratories in China, but there is a lack of high-quality technicians to apply these advancements to scientific research. In addition, the traditional education and apprenticeship systems have been demonstrated little progress. To address this gap, West China Hospital of Sichuan University established a 2-year educational program for laboratory technology in 2006 based on the residency training program. The project integrates scientific methods into the research laboratory technician training in relevant disciplines, and has developed a systematic, scientific, and effective standardized training system to cultivate high-level and stable experimental technician team for the need of advanced laboratories, which has been demonstrated greatly improve the efficiency of biomedical researchers and laboratory facilities. In this article, we introduce the practical experience in establishment and development of a standardized training system for biomedical laboratory technicians to ensure the sustainable development of medical researches.
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Apelin is a novel endogenous active peptide. The aim of this study is to investigate whether apelin in the paraventricular nucleus (PVN) can improve the cardiac function in rats subjected to thoracic surgery trauma, and whether it is involved in the protective effect of electro-acupuncture (EA). Sprague-Dawley rats were randomly divided into non-stressed group (control), thoracic surgical trauma stressed group (trauma) and bilateral Neiguan EA applied on thoracic surgical trauma stressed group (trauma + EA-PC 6). The mRNA expressions of apelin receptor (APJR) and apelin in the PVN were detected by real time-PCR. The exogenous apelin-13 (6 mmol/L, 0.1 μL) was microinjected into the rat PVN in the thoracic trauma group, and the effects of apelin-13 on the blood pressure (BP), heart rate (HR) and the discharge of rostral ventrolateral medulla (RVLM) neurons were observed through the simultaneous recording technology by polygraph. The results showed that the APJR mRNA expression was significantly decreased in the rats of trauma group as compared with that in the control group (P < 0.05), and a decline trend of apelin mRNA expression was also observed. EA application at bilateral Neiguan acupoints partially recovered the decline of APJR and apelin mRNA expression by the treatment of thoracic trauma. Both mean arterial pressure and HR in the thoracic surgical trauma group were significantly increased by the microinjection of exogenous apelin-13 into the PVN (P < 0.05), and the single-unit discharge rate of RVLM neurons also had an increasing trend. These results suggest that apelin in the PVN can improve the cardiac function of thoracic surgical trauma rats, and may be involved in the protective effects of EA.
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Objective To master the condition of iodine deficiency disorders (IDD),residents iodine nutritional status and implementation of prevention measures in Gansu Province and to provide a basis for developing control strategies.Methods Thirty primary schools were selected in Gansu Province utilizing cluster sampling methodology in 2011,In each selected school,40 children aged 8-10 were randomly selected for thyroid examination and urine samples were collected from 12 children,at the same time measuring the average daily salt intake of domestic residents by 3 days weighing method.On the spot random urine samples and salt samples were collected from a subset of children included in the study.Three towns near the selected school were selected randomly and random urine samples were collected from 5 pregnant and 5 lactating women in each selected town.One drinking water sample was collected for analysis from different sources in five directions(east,south,west,north and central)in each administrative village with the sampled schools.In areas with centralized water supply,two tap water samples were collected for analysis.Results The water iodine median of 83 water samples was 2.02 μg/L,the range was 0.20-36.92 μg/L,and iodine median of 1199 salt samples was 27.4 mg/kg,iodine level in 89.2％ (74/83) of the water samples was lower than 10 μg/L.The iodized salt coverage rate was 98.0％ (1175/1199),the qualified rate of iodized salt was 90.3％ (1061/1175) and the consumption rate of qualified iodized salt was 88.5％ (1061/1199).Total of 360 salt samples intake of households were collected,per capita daily salt was 8.5 g,and the range was 2.5-17.8 g.Total of 1200 children thyroid were checked,the thyroid goiter rate(TGR)of children was 2.8％(34/1200) by B-ultrasound and 3.5％ (42/1200) by palpation.Total of 359,450 and 450 urine samples of childen aged 8-10,pregnant and lactating women,the urinary iodine median were 216.0,168.6,161.9 μg/L,respectively.Conclusions Great progress has been made in the prevention and control of IDD in Gansu Province.IDD has been controlled effectively and the urinary iodine medians are at optimal levels.
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<p><b>OBJECTIVE</b>Improvement in lung function was reported after acupuncture treatment of chronic obstructive pulmonary disease (COPD), but little is known about the underlying mechanisms. Because an immune response imbalance could be seen in COPD, we hypothesize that electroacupuncture (EA) may play a role in regulating inflammatory cytokines and contribute to lung protection in a rat model of smoke-induced COPD.</p><p><b>METHODS</b>A COPD model using male Sprague-Dawley rats exposed to cigarette smoke was established. The rats were randomly divided into four groups (control, sham, COPD, and COPD plus EA), and COPD model was evaluated by measuring pulmonary pathological changes and lung function. EA was applied to the acupuncture point Zusanli (ST36) for 30 min/d for 14 d in sham and COPD rats. Bronchoalveolar lavage fluid (BALF) was used to measure levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and malonaldehyde (MDA).</p><p><b>RESULTS</b>Compared with the control rats, COPD rats had significant changes in lung resistance (RL) and lung compliance (CL) (both P<0.01), bronchi and bronchiole airway obstruction (P<0.01), and levels of MDA, TNF-α, and IL-1β (P<0.01). There were no significant differences between the control and the sham groups. Compared with the COPD rats, the COPD plus EA rats had decreased RL and increased CL (both P<0.05), and reduced bronchi and bronchiole airway obstruction (P<0.05, P<0.01, respectively), while levels of TNF-α, IL-1β, and MDA in BALF were lowered (P<0.05 and P<0.01, respectively). However, TNF-α and IL-1β levels of the EA group rats remained higher than those of the control group (P<0.05).</p><p><b>CONCLUSION</b>EA at ST36 can reduce lung injury in a COPD rat model, and beneficial effects may be related to down-regulation of inflammatory cytokines. The anti-inflammatory and antioxidant effects may prolong the clinical benefit of EA.</p>
Subject(s)
Animals , Humans , Male , Rats , Acupuncture Points , Bronchoalveolar Lavage Fluid , Allergy and Immunology , Disease Models, Animal , Electroacupuncture , Interleukin-1beta , Allergy and Immunology , Pulmonary Disease, Chronic Obstructive , Allergy and Immunology , Therapeutics , Rats, Sprague-Dawley , Smoking , Tumor Necrosis Factor-alpha , Allergy and ImmunologyABSTRACT
Objective To investigate the control status of iodine deficiency disorders (IDD) in the highrisk areas of Gansu province,and to provide a scientific basis for development of effective preventive measures.Methods Twelve counties with high-risk areas of IDD in Gansu province were selected into the survey in 2007 -2009.All patients with suspected cretinism born after the first of January,1997 were enrolled in the study from the 12 counties.Meanwhile,three townships were chosen in each of the 12 counties,two villages were taken in each township,40 children aged 8 to 10 in each village primary school were selected to carry out thyroid examination by B-ultrasonography and palpation,urinary iodine(UI) test,and intelligence quotient(IQ) test; 30 women of childbearing age were selected in each village to fill in the questionnaire,and to test their urinary and salt iodine,and the local salt-related situation was investigated.Results In the 12 high-risk counties,7 were diagnosed as new cretinism cases from a total of 120 suspected cases of cretinism.The goiter rate of children aged 8 - 10 by Bultrasound was 6.8％(290/4281 ),5 counties had goiter rates higher than 5％,of which 3 counties had goiter rates higher than 10％.The average IQ of children was 82.38.The median urinary iodine(MUI) of children was 180.34 μg/L,the ratio of UI ＜ 50 μg/L was 11.0％(482/4383).The MUI of women of childbearing age was 175.91 μg/L,the ratio of UI ＜ 50 μg/L was 16.5％(126/762).MUI of women of childbearing age was less than 100.0 μg/L in Xiahe and Dongxiang counties,which were 95.24 μg/L and 66.30 μg/L,respectively.The coverage rate of iodized salt in 8 of the 12 counties was more than 95％,and that of the remaining four counties was ＜ 85％,of which the coverage rates of iodized salt were only 39.2％ (47/120)and 66.7％ (120/180),respectively,in Guanghe and Dongxiang counties.Fourteen point nine percent (206/1380) of the residents complained that iodized salt was not convenient to buy and 87.7％ (1210/1380) complained that the current price of these salts exceeded the accepted range.Only 29.9％(413/1380)of the housewives knew how to prevent IDD.Conclusions Impact factors of IDD in high-risk areas are widespread.The monitoring of IDD in high-risk areas should be strengthened.Effective measures should be taken to ensure adequate iodine nutrition of people at risk.At the same time,iodized salt-based comprehensive prevention measures should be strengthen and a long-term effective control strategy of IDD should be established.
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In this study, we used techniques of in situ hybridization, immunohistochemistry, electric stimulation of the dorsal periaquaductal gray of the midbrain (dPAG) and microinjection to investigate the changes of preproadrenomedullin (ppADM) gene expression encoding adrenomedullin (ADM) and ADM-like immunoreactivity (ADM-IR) in the medulla oblongata, especially in the rostral ventrolateral medulla (rVLM) of the rats receiving foot-shock and noise stress for 5 d, and the potential role of ADM in cardiovascular component of defense response in the rVLM. The results showed that ppADM mRNA and ADM-IR were widely distributed throughout the medulla oblongata. Highly labeled neurons were found in the ventrolateral reticular nucleus and hypoglossal nucleus. Moderately labeled neurons were seen in the facial, ambiguus, lateral reticular, paragigantocellular reticular, and inferior olivary nuclei. Weak signal was present over neurons of nucleus of the solitary tract. The expression of ppADM mRNA and ADM-IR increased significantly after foot shock and noise stress for 5 d as compared with that in control group (P<0.01). On the other hand, stimulation of the right dPAG raised the artery pressure (AP) rapidly from (116.4+/-8.9) mmHg to (140.0+/-9.8) mmHg, and heart rate (HR) from (378.0+/-7.5) beats/min to (413.0+/-8.2) beats/min, respectively, in the normotensive rats. After unilaterally microinjection of hADM(22-52) (a specific antagonist of ADM receptor, 1 pmol) into the right rVLM of the normotensive rats for 10 min, the rats received the stimulation of the dPAG again. Then we found that the DeltaAP and DeltaHR were lowered significantly within 60 min compared with those without hADM(22-52) application (P<0.05). After unilaterally microinjection of 0.1 pmol rat ADM (rADM) into the rVLM, dPAG stimulation caused no significant changes in DeltaAP and DeltaHR. Our results that foot-shock and noise stress induced significant increases of ppADM mRNA and ADM-IR in the rVLM, and microinjection of ADM receptor antagonist hADM(22-52) into the rVLM partly blocked the cardiovascular component of stress-defensive response induced by stimulation of the dPAG, suggest that ADM in the rVLM might be an important neurotransmitter or neuroregulator in the regulation of cardiovascular function in the stress-related defensive response.
Subject(s)
Animals , Rats , Adrenomedullin , Physiology , Blood Pressure , Electric Stimulation , Heart Rate , Medulla Oblongata , Physiology , Microinjections , Neurons , Physiology , Periaqueductal Gray , Physiology , Protein Precursors , Physiology , Rats, Sprague-DawleyABSTRACT
han that in the control one (t=3.94, P<0.01).Conclusion Social skills training can effectively improve subjective satisfactions of the long-terra hospitalized patients with chronic schizophrenia.
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<p><b>BACKGROUND</b>The down-regulation of constitutive nitric oxide synthase (cNOS) and up-regulation of inducible nitric oxide synthase (iNOS) are associated with the allergen-provocated airway hyperresponsiveness (AHR). This study aimed to determine whether their alteration also plays an important role in the AHR induced by lipopolysaccharide (LPS).</p><p><b>METHODS</b>Hartley male guinea pigs, weighing between 250 g and 350 g, were injected with LPS at a dose of 1 mg/kg every 24 hours for three days. A non-selective NOS inhibitor, N(omega)-nitro-L-arginine methyl ester (L-NAME), or a selective inducible NOS inhibitor, aminoguanidine (AG), were used thirty minutes before each injection of LPS. Airway reactions, nitric oxide (NO) production and inflammatory changes were detected 24 hours after the last dose of LPS.</p><p><b>RESULTS</b>AG significantly decreased the NO production in the bronchoalveolar lavage fluid (BALF) and sharply reduced the intensity of bronchoconstriction to histamine challenge. L-NAME also significantly decreased the NO production in the BALF, but had no effect on airway reactions or, perhaps, a tendency to enhance the intensity of AHR.</p><p><b>CONCLUSIONS</b>The data suggest that inducible NOS contributes to the AHR induced by repetitive intraperitoneal LPS, and constitutive NOS was also involved.</p>
Subject(s)
Animals , Male , Airway Resistance , Bronchial Hyperreactivity , Enzyme Inhibitors , Pharmacology , Guanidines , Pharmacology , Guinea Pigs , Lipopolysaccharides , Toxicity , NG-Nitroarginine Methyl Ester , Pharmacology , Nitric Oxide , Nitric Oxide Synthase , PhysiologyABSTRACT
Increasing lines of evidence has been accumulated that nitric oxide (NO) and nitric oxide synthase (NOS) distribute plentifully in the rostral ventrolateral medulla (RVLM) and contribute to cardiovascular regulation. In the present study, the expressions of neuronal and inducible isoform of NOS (nNOS and iNOS) were observed in the RVLM of acute myocardial ischemia (AMI) Wistar rats experienced electroacupuncture (EA) treatment, thereby the cardiovascular effects of NO in the RVLM were investigated and the mechanism of acupuncture effect on AMI was inferred. The results indicated that in the AMI rats, cardiac functions were markedly attenuated with high serum level of brain natriuretic peptide (BNP) and norepinephine (NE), the number of nNOS-immunoreactive cells and nNOS mRNA exprossion in the RVLM area were increased, while those of iNOS were lowered. EA at "Neiguan" acupoints (Pe 6) 30 min daily for successive 5 d resulted in an improvement of the cardiac functions, decreases in NE and BNP levels; it also increased the expression of iNOS and decreased the expression of nNOS in the RVLM. These results suggest that the curative effect of acupuncture on AMI is possibly attributable to the differential regulation of NOS/NO in the RVLM, leading to decreased sympathetic outflow and improvement of cardiac functions.
Subject(s)
Animals , Rats , Acupuncture Therapy , Electroacupuncture , Medulla Oblongata , Metabolism , Myocardial Ischemia , Metabolism , Therapeutics , Nitric Oxide , Metabolism , Nitric Oxide Synthase Type I , Metabolism , Nitric Oxide Synthase Type II , Metabolism , Rats, WistarABSTRACT
15 scores were randomly divided into therapeutic group (30 cases)and control group(30 cases).The two groups were treated with the same conventional therapy. From the 1st day of admission,Xuebijing injection 80 ml was given by intravenous drip once for every 12 hours for 7 days to the therapeutic group.The level of tumor necrosis factor-?(TNF-?),interleukin-1?(IL-1?),IL-6,IL-10,and APACHEⅡscore were tested on 1,3,5 and 7 days after admission.The case fatality and incidences rates of sepsis and MODS in both groups were recorded.Results Compared with the control group,APACHEⅡscore,TNF-?,IL-1?,IL-6 and IL-10 of the therapeutic group were lower significantly on the 3rd day after admission,especially on the 5th day(all P
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To investigate the eletrophysiological effect of rat adrenomedullin (rADM) on barosensitive neurons in the rostral ventrolateral medulla (rVLM) and its potential mechanisms, the extracellular recording and multi-barrel iontophoresis methods were used. Of the 29 barosensitive neurons in the rVLM, 20 neurons demonstrated excitatory response to iontophoretically applied rADM and increased the firing rate from (10.8 +/- 2.7) spikes/s to (14.6 +/- 3.6), (19.8 +/- 4.7) and (31.9 +/- 6.4) spikes/s (P<0.05, n=20) at the current of 30, 60 and 90 nA, respectively. Application of human adrenomedullin (22-52) [hADM (22-52)], a specific antagonist of rADM receptor, distinctly attenuated the augmentation of firing rate induced by rADMjthe firing rate was increased by 15.4% [(11.4 +/- 2.5) spikes/s, P<0.05, n=10]. Another antagonist, human calcitonin gene-related peptide (8-37) [hCGRP (8-37)] had no significant effect on rADM-induced excitation. Other 23 barosensitive neurons were recorded to test the influence of nitric oxide synthase (NOS) inhibitors on the excitatory effect of rADM. In 10 neurons, 7-NiNa (neuronal NOS inhibitor) decreased the firing rate from (10.1 +/- 3.5) spikes/s to (7.5 +/- 2.5), (5.3 +/- 2.1) and (3.1 +/- 1.4) spikes/s (P<0.05, n=10) at the current of 10, 20 and 40 nA, respectively. The excitatory effect of rADM (60 nA, 30 s) during 7-NiNa application was nearly eliminated and the magnitude of firing rate was increased only by 17% of the basal level (6.2 +/- 1.9) spikes/s (P<0.05, n=7). While aminoguanidine (AG, iNOS inhibitor) increased the firing rate at the resting level from (11.5 +/- 5.1) spikes/s to (17.8 +/- 5.6), (22.5 +/- 6.3) and (29.1 +/- 6.4) spikes/s (P<0.05, n=8) at the current of 10, 20 and 40 nA in 8 barosensitive neurons, respectively. When rADM (60 nA, 30 s) was delivered during AG iontophoresis period, the firing rate significantly increased by 60% of the basal level [(22.5 +/- 6.3) spikes/s, n=5]. These results indicate that rADM activates the barosensitive neurons in the rVLM directly and acts as a cardiovascular regulator, and that this function might be mediated by its specific receptor. NO, mainly neuronal NOS-originated might be involved in the excitatory effect of rADM in the rVLM.
Subject(s)
Animals , Male , Rats , Adrenomedullin , Physiology , Electrophysiological Phenomena , Medulla Oblongata , Physiology , Neurons , Physiology , Nitric Oxide , Physiology , Nitric Oxide Synthase Type I , Physiology , Pressoreceptors , Physiology , Rats, Sprague-DawleyABSTRACT
To explore the underlying mechanism(s) of pulmonary arterial hypertension in endotoxic shock, the roles of N-acetylcysteine (NAC), nitric oxide (NO) and carbon monoxide (CO) were investigated. Pulmonary arterial rings (3-mm width) were prepared from 24 rabbits. Lipopolysaccharide (LPS), after 7-hour incubation, decreased the endothelium-dependent relaxation response of the arterial ring (pre-contracted with phenylephrine) to acetylcholine (1 mumol/L), but did not affect the endothelium-independent relaxation response to sodium nitroprusside. The LPS effects were reduced by a concomitant incubation with the free radical scavenger (NAC), NO donor (L-arginine), and CO donor (hemin), respectively. On the other hand, the LPS effects were enhanced by applying heme oxygenase-1 (HO-1) inhibitor (zinc protoporphyrin) to block CO production. The response to acetylcholine changed from relaxation to contraction, however, the contractile response to phenylephrine increased significantly after pre-incubation with nitric oxide synthase (NOS) inhibitor (L-NAME) to block NO production, confirming the importance of CO and NO. These results show that LPS impairs endothelium-dependent relaxation of the pulmonary artery, which can be greatly reduced by the antioxidant, or by supplying with NO and CO. Thus, multiple factors are involved in this model of endotoxin-induced pulmonary hypertension.
Subject(s)
Animals , Male , Rabbits , Acetylcysteine , Metabolism , Carbon Monoxide , Metabolism , Hypertension, Pulmonary , Lipopolysaccharides , Toxicity , Nitric Oxide , Metabolism , Pulmonary Artery , Shock, SepticABSTRACT
Experiments were performed on male Sprague-Dawley (SD) rats anesthetized with a mixture of urethane and chloralose. A rat model of acute myocardial ischemia (AMI) was made by ligation of the left anterior descending branch of the coronary artery (LAD). After the LAD ligation, the ischemia area of the left ventricular wall became somewhat pale immediately. Under a light microscope, the pathological examination revealed that all the cells were swollen and in red color when the cardiac section was stained with hematoxylin basic fuchsin picric acid (HBFP), which indicated a typical change in the myocardial ischemia. In the AMI model, it was found that cardiac functions were markedly attenuated, such as decreases in the heart rate (HR), mean arterial pressure (MAP), left ventricular systolic pressure (LVSP), maximal rate for left ventricular pressure rising and declining (+/-dp/dt(max)), velocity of contractile element (V(CE)) and total area of cardiac force loop (L(0)), and an increase in the left ventricular end diastolic pressure (LVEDP). In such AMI rats, application of electroacupuncture (EA) at "Neiguan" acupoints (Pe 6) for 20 min could obviously improve the above-mentioned cardiac functions. After microinjection of nitro-L-arginine (L-NNA), an inhibitor of nitric oxide synthase (NOS), was made into the rostral ventrolateral medulla (RVLM), the curative effect of EA on myocardial ischemia was reduced significantly or abolished, while after microinjection of normal saline of the same volume was made into the RVLM, the improving effect of EA remained. These results suggest that the effect of EA on myocardial ischemia is possibly mediated by the nitric oxide (NO) in the RVLM.
Subject(s)
Animals , Male , Rats , Acupuncture Points , Electroacupuncture , Medulla Oblongata , Metabolism , Myocardial Ischemia , Metabolism , Nitric Oxide , Physiology , Rats, Sprague-Dawley , Ventricular FunctionABSTRACT
In this study, reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the changes in mRNAs levels of preproadrenomedullin (ppADM) gene encoding adrenomedullin (ADM) and the essential receptor components of ADM, calcitonin receptor-like receptor (CRLR), and the receptor activity modifying protein 2 and 3 (RAMP2 and RAMP3) in the medulla oblongata, hypothalamus, midbrain, pituitary gland and adrenal gland of the stress-induced hypertensive rats. It was shown that chronic foot-shock and noise stress for 15 consecutive days induced a significant increase in systolic blood pressure (SBP) and unique changes in ppADM and its receptor components mRNAs in all areas studied. As compared with the control group, the level of ppADM mRNA, normalized against a glyceraldehydes-3-phosphate dehydrogenase (GAPDH) control, was up-regulated in the hypothalamus-pituitary-adrenal (HPA) axis, but down-regulated in the medulla oblongata and midbrain (P<0.01 and P<0.05, respectively). The relative amount of CRLR mRNA was higher in the hypothalamus than that in other areas. The level of CRLR mRNA expression was significantly increased in the medulla oblongata of the stress group (P<0.01), but decreased in the midbrain (P<0.01) as well as hypothalamus(P<0.05), as compared with that of the control group. Chronic stress for 15 consecutive days produced an increase in the level of RAMP2 mRNA expression in the medulla oblongata (P<0.01) and a decrease in the adrenal gland (P<0.01), as compared with the control. No significant stress-related changes in RAMP2 mRNA were observed in the midbrain, hypothalamus and pituitary gland. The amount of RAMP3 mRNA was relatively higher in the midbrain and hypothalamus than that in the medulla oblongata, adrenal gland and adrenal gland. Stress-induced hypertensive rats exhibited an increased RAMP3 mRNA expression in the hypothalamus and pituitary gland (P<0.01 and P<0.05, respectively) and a decrease in the adrenal gland and midbrain (P<0.05). No significant stress-related change in RAMP3 mRAN was observed in the medulla oblongata. Taken together, our results indicate that the significant changes in ppADM and its receptor components mRNAs expression in the HPA axis and autonomic centers may be related to the development of the stress-induced hypertension. Nevertheless, the pathophysiological significance of brain-derived ADM and its receptors in stress and blood pressure regulation and their roles in stress-induced hypertension still await further investigation.
Subject(s)
Animals , Male , Rats , Adrenomedullin , Brain Stem , Metabolism , Hypertension , Metabolism , Hypothalamo-Hypophyseal System , Metabolism , Peptides , Genetics , Metabolism , Pituitary-Adrenal System , Metabolism , RNA, Messenger , Genetics , Rats, Sprague-Dawley , Receptors, Adrenomedullin , Receptors, Peptide , Genetics , Stress, PhysiologicalABSTRACT
This study, using cultured bovine pulmonary artery endothelial cells (BPAECs), was undertaken to investigate the roles of endogenous ONOO(-) in LPS-caused injury in endothelial cells. The fluorescent intensity of nitrotyrosine (NT), a specific marker of ONOO(-) generation, in BPAECs represented the content of endogenous ONOO(-) generation. The fluorescent intensity of NT and the number of NT positive cells were detected with flow cytometry (FCM), and the percentage of NT positive cells was calculated. The results are as follows. (1) LPS (1, 5 and 10 microg/ml) caused a marked increase in fluorescent intensity of NT in a dose-dependent manner, which was significantly increased compared to the vehicle group (P<0.01).The number and percentage of NT positive cells were markedly increased (both P<0.05 vs vehicle group). Aminoguanidine (AG), a selective inhibitor of inducible nitric oxide synthase (iNOS), inhibited LPS-induced increase in fluorescent intensity of NT in BPAECs. However, the number and percentage of NT positive cells had a tendency to reduce. (2) LPS brought about an enhancement in MDA content and the activity of LDH in cultured supernatant. AG reversed the enhancement in MDA content induced by LPS (P<0.01). In contrast, AG had a marginal effect on the activity of LDH. (3) LPS induced an increase in apoptotic rate in BPAECs in a dose-dependent manner. The number of apoptotic cells markedly increased as well. Some BPAECs stained with fluorescent probe ethidium bromide showed morphological features of apoptosis with chromatin condensation and nuclear fragmentation. AG reduced the apoptotic rate and the number of apoptotic cells, both of which were still higher than those of vehicle group (P<0.05). LPS led to inhibition of mitochondrial respiration and membrane potential in an accumulation manner. In conclusion, LPS caused injury to cultured BPAECs and increased the production of ONOO(-).The cytotoxicity of LPS may be mediated by the endogenous ONOO(-).
Subject(s)
Animals , Cattle , Cells, Cultured , Endothelial Cells , Cell Biology , Metabolism , Pathology , Lipopolysaccharides , Toxicity , Lung Injury , Peroxynitrous Acid , Physiology , Pulmonary Artery , Cell Biology , PathologyABSTRACT
<p><b>AIM</b>To investigate the alleviating effect of N-acetylcysteine (NAC) on lung injury induced by lipopolysaccharides (LPS) and its mechanism.</p><p><b>METHODS</b>The effects of NAC on changes of the pulmonary arterial reactivity and the ultrastructure of pulmonary arterial endothelium induced by LPS were observed with the isolated artery ring technique and scanning electron microscope (SEM). Malondialdehyde (MDA), nitric oxide (NO) contents and superoxide dismutase (SOD) activity of pulmonary artery tissues were detected.</p><p><b>RESULTS</b>The exposure of pulmonary artery to LPS (4 microg/ml, 7 h) led to reduction of endothelium-dependent relaxation response to acetylcholine (ACh), which was reversed by the concomitant exposure to NAC (0.5 mmol/L, 7 h), whereas NAC itself had no effect on the response. Significant structural injury were observed under SEM in LPS group and alleviated the changes in LPS + NAC group. The MDA, NO contents increased but SOD activity decreased in LPS group, which were reversed by the concomitant exposure to NAC.</p><p><b>CONCLUSION</b>NAC protects pulmonary artery endothelium and enhances endothelium-dependent relaxation response of pulmonary artery by antioxidation effect, which may be one of the mechanisms of its reversing pulmonary artery hypertension and following lung injury induced by LPS.</p>