A comprehensive study of long-term skeletal changes after spinal cord injury in adult rats

Spinal cord injury（SCI）-induced bone loss represents the most severe osteoporosis with no effective treatment.Past animal studies have focused primarily on long bones at the acute stage using adolescent rodents. To mimic chronic SCI in human patients, we performed a comprehensive analysis of long-term structural and mechanical changes in axial and appendicular bones in adult rats after SCI. In this experiment, 4-month-old Fischer 344 male rats received a clinically relevant T13 contusion injury. Sixteen weeks later, sublesional femurs, tibiae,and L4 vertebrae, supralesional humeri, and blood were collected from these rats and additional non-surgery rats for micro-computed tomography（m CT）, micro-finite element, histology, and serum biochemical analyses.At trabecular sites, extreme losses of bone structure and mechanical competence were detected in the metaphysis of sublesional long bones after SCI, while the subchondral part of the same bones showed much milder damage. Marked reductions in bone mass and strength were also observed in sublesional L4 vertebrae but not in supralesional humeri. At cortical sites, SCI induced structural and strength damage in both sub- and supralesional long bones. These changes were accompanied by diminished osteoblast number and activity and increased osteoclast number and activity. Taken together, our study revealed site-specific effects of SCI on bone and demonstrated sustained inhibition of bone formation and elevation of bone resorption at the chronic stage of SCI.

Glucocorticoid receptor expression on acute lung injury induced by endotoxin in rats

In cases of severe sepsis and septic shock, a series of pathophysiological changes lead to multiple organ dysfunction syndrome.This study aimed to investigate the expression of glucocorticoid receptor mRNA in the rat lung following endotoxin （LPS） induced shock. Totally 56 SD rats were randomly divided into 4 groups： LPS shock group （n=16）, LPS＋vasoactive intestinal peptide group（VIP） group, （n=16）, LPS＋VIP＋ glucocorticoid （GC） group, （n=16）,and control group （n=8）. LPS shock was induced by intravenous injection of LPS （10 mg/kg） in rats. Within 15 minutes after LPS injection, rats in the treatment groups received VIP （5 nmol/kg） or VIP and methylprednisolone （3 mg/kg）. The control group was given normal saline instead of LPS. The rats of the four groups were sacrificed at 6 hours,24 hours after injection respectively, and the lung tissues were collected. Pathological changes of the lungs were examined by light microscopy and electron microscopy. GRmRNA expression in the lung tissues was evaluated by RT-PCR. In the LPS shock group, lung histopathology demonstrated destruction of the alveolar space,widening of the inter-alveolar space, inflammatory cell infiltration and interstitial edema. However,pathological changes in the LPS＋ VIP group and LPS＋ VIP＋GC group were milder than those in the LPS shock group. Six hours after LPS injection, GR mRNA expression was down-regulated in the LPS group （0.72± 0.24） and LPS＋ VIP group （0.88±0.27） （P〈0.05） as compared with the control group （1.17±0.22）. The LPS shock group showed a more significant down-regualtion than the LPS＋VIP group, but the difference was not statistically significant （P〉0.05）. In contrast, GRmRNA expression in the LPS＋ VIP＋GC group was significantly up-regulated at 6 hours and further at 24 hours （1.45±0.32 and 1.91±0.46 respectively） （P〈0.05）. GrmRNA expression decreased in LPS induced lung injury in rats. Combined treatment with VIP and GC mitigated lung injury ang inflammation. The mechanism may be related to up-regulation of GR mRNA expression.

Zinc-deficient diet aggravates ventilation-induced lung injury in rats

We investigated the effects of zinc deficiency on acute lung injury （ALI） induced by mechanical ventilation. Male Sprague-Dawley rats were fed with a zinc-deficient or zinc-proficient diet for 4 weeks, and then received mechanical ventilation at normal frequency and pressure for 30 min. Total protein, cell count, the number of poly- morphonuclear neutrophil （PMN） in the bronchoalveolar lavage （BAL）, and vascular endothelial growth factor （VEGF） expression in the lung were determined. Activation of nuclear factor-t^B （NF-~cB） was detected by exam- ining the phosphorylation of NF-kB （pNF-kB p65） and the expression of inhibitor of NF-kB （pI-kBa）. Compared to the controls, total cell count and the number of PMNs were significantly increased to 160% and 140%, respec- tively, in zinc-deficient rats treated with ventilation. Activation of NF-kB was significantly increased and VEGF was also increased to three-folds. Zinc deficiency aggravated the inflammatory response in rats and was associated with the overexpression of VEGF in response to mechanical ventilation. Zinc supplementation may be beneficial to zinc-deficient patients during mechanical ventilation.

The Mechanism of Acute Lung Injury Induced by Nickel Carbonyl in Rats

Nickel carbonyl is a highly toxic metal compound produced from the reaction that occurs between nickel and carbon monoxide under pressure. As previously reported, nickel carbonyl can cause acute aspiration pneumonia, and animal experiments showed it was toxic to animal lung, liver, brain, and other vital organs[1]. However, few studies have investigated nickel carbonyl poisoning in humans.

Functional changes of pulmonary surfactant in rats with lung injury induced by endotoxin

We studied the functional changes of pulmonary surfactant （PS） in acutelung injury models produced by endotoxin injection (E.coli O55B5) in rats.The sur-face properties of the lung lavage liquid and the total phospholipids （TPL） ex-tracted from it were assessed on a modified Wilhelmy film balance.γ-A isothermof the lavage liquid revealed an increase in minimum surface tension and a de-crease in hysteresis area,recruitment index and stability index,whereas that ofTPL extracted from it did not show any change except for hysteresis area.Thesurface activity correlates positively with the TPL content but negatively with thetotal protein content in the lavage liquid.The findings indicated that there was adysfunction of PS in rats with the lung injury induced by endotoxin,suggestingthat the function deficiency of PS might be caused by decreased phospholipidsand increased proteins in the alveoli.

Changes of pulmonary beta-adrenergic receptors and their relationship with membranous phospholipid metabolism in endotoxin-induced lung injury in rats

The changes of beta-adrenergic receptors (AARs) in lung tissue in endotoxin-induced acute lung injury was investigated with radioligand bindig assay in rats. The lipid fluidity and phospholipid content of the cellular membrane of lung tissue were measured with fluorescent polarization and high performance liquid chromatography respectively. The findings were as follows:1- Four hours after endotoxin injection, there was a 47% decrease of the maximal binding capacity of fyARsas compared with the control.2. Endotoxin was able to decrease the lipid fluidity and phospholipid content of the pulmonary cellular membrane markedly and at the same time. There was an elevated activity of phospholipase A2 in the pulmonary tissueThese findings suggest that the decrease of the binding capacity of &ARs results in a decrease of the PAR mediated functions, which plays a ro1e in the pathogensis of endotoxin-induced acute lung injury and the activation of phospholipase A2 which is an important factor to reduce the phospholipid content of cell membrane and subsequently to decrease its lipid fluidity, can result in a reduction of the lateral diffusion and rotatory movement of β-ARs and to decrease the chances of β-ARs to bind with the ligands.

Establishment of Acute Lung Injury Model Induced by Intraperitoneal Injection of Lipopolysaccharide in Rats

The model of acute lung injury(ALI)was established by intraperitoneal administration,but there was no time-point observation and comparison.ALI model was established by intraperitoneal injection of lipopolysaccharide(LPS)at the concentration of 10 mg·kg^-1 (10 mg LPS dissolved in 1 mL normal saline to prepare 1 mL·kg^-1solution)in rats.The control group(CG)was intraperitoneally injected with saline of the same dose.In the LPS group,lung tissues were collected at 4,6,8,12 and 24 h after administration.Then,the morphology changes,the ratio of wet-to-dry weight(W/D),the expression of interleukin-1β(IL-1β)and tumor necrosis factor-α(TNF-α)proteins,the levels of malondialdehyde(MDA),the activities of superoxide dismutase(SOD),glutathione peroxidase(GSH)were measured.To verify the success of the model,the degrees of lung injury via Western blot,RT-PCR,ELISA and other techniques were detected at different time points,and the severe time of the ALI model established was deterimined by intraperitoneal administration,which provided a stable model basis for the study of the pathogenesis of ALI in the future.The results showed that the lung injury occurred in LPS group.W/D and lung pathological changes at 12 and 24 h of LPS group were significantly different from those in the CG.Compared with the CG,the expression of IL-1βand TNF-αproteins and the content of MDA in lung tissues of LPS group increased and most significant difference was found at 12 and 24 h(p<0.01).Compared with the CG,the activities of SOD and GSH in LPS 12 h group decreased significantly(p<0.01).In conclusion,inflammation and oxidative damage were the main causes of the ALI in rats.Lung injury was most obvious 12 h after intraperitoneal injection of 10 mg·kg^-1 LPS.

Effects of methyl palmitate and lutein on LPS-induced acute lung injury in rats

AIM: To investigate the effects of methyl palmitate and lutein on lipopolysaccharide(LPS)-induced acute lung injury(ALI) in rats and explore the possible mechanisms. METHODS: Male Sprague-Dawley rats were divided into 4 groups:(1) control;(2) LPS;(3) Methyl palmitate; and(4) Lutein groups. Methyl palmitate(300 mg/kg, ip) was administered 3 times per week on alternating days while lutein(100 mg/kg, oral) was given once daily. After 1 wk of vehicle/methyl palmitate/lutein treatment, ALI was induced by a single dose of LPS(7.5 mg/kg, iv). After 24 h of LPS injection, animals were sacrificed then biochemical parameters and histopathology were assessed. RESULTS: Treatment with methyl palmitate attenuated ALI, as it significantly decreased the lung wet/dry weight(W/D) ratio, the accumulation of the inflammatory cells in the bronchoalveolar lavage fluid(BALF) andhistopathological damage. However, methyl palmitate failed to decrease lactate dehydrogenase(LDH) activity in BALF. On the other hand, lutein treatment produced significant anti-inflammatory effects as revealed by significant decrease in accumulation of inflammatory cells in lung, LDH level in BALF and histopathological damage. Methyl palmitate and lutein significantly increased superoxide dismutase(SOD) and reduced glutathione(GSH) activities with significant decrease in the lung malondialdehyde(MDA) content. Importantly, methyl palmitate and lutein decreased the level of the inflammatory cytokine tumor necrosis factor-α(TNF-α) in the lung. Lutein also reduced LPS-mediated overproduction of pulmonary nitrite/nitrate(NO-2/NO-3), which was not affected by methyl palmitate pretreatment. CONCLUSION: These results demonstrate the potent protective effects of both methyl palmitate and lutein against LPS-induced ALI in rats. These effects can be attributed to potent antioxidant activities of these agents, which suppress inflammatory cell infiltration and regulated cytokine effects.

Expression of bradykinin as a substrate of CD26 /DPP IV in rats ischemia/reperfusion injury following lung transplantation

Objective To investigate the expression of bradykinin as a substrate of CD26 /DPP IV in rats with ischemia/reperfusion injury following lung transplantation ( LTx) . Methods Thirty - six syngeneic male SD rats were randomly allocated into control group and experimental group ( n = 18 each) ,and 36 rats served as do-

The Role of Oxygen Radicals in Rat Acute Lung Injury Induced by Phorbol Myristate Acetate

We tried to clarify the role of oxygen radicals released from granulocytes stimulated byphorbol myristate acetate(PMA) in rat acute lung injury. It was found that DNA strand-breakdamage(DSBD) in peripheral white blood cells (WBC) was significantly increased 40 min after injec-tion of PMA. DSBD in lung tissue of rats treated with PMA was also markedly increased comparedwith the controls. The PMA-treated rats showed significantly higher lipid-peroxide (LPO) level inplasma and lung tissue hemogenate than the controls did. These results suggest that determination ofDSBD, a simple and sensitive indicator for oxygen radical damaging, might be useful in thediagnosis of adult respiratory distress syndrome (ARDS), when it is used together with themeasurement of plasma LPO.

Lipopolysaccharide “Two-hit” Induced Refractory Hypoxemia Acute Respiratory Distress Model in Rats

To establish a stable and reliable model of refractory hypoxemia acute respiratory distress syndrome （ARDS） and examine its pathological mechanisms, a total of 144 healthy male Wistar rats were randomized into 4 groups： group Ⅰ （saline control group）, group Ⅱ （LPS intravenous ＂single-hit＂ group）, group Ⅲ （LPS intratracheal ＂single-hit＂ group） and Group IV （LPS ＂two-hit＂ group）. Rats were intravenously injected or intratracheally instilled with a large dose of LPS （10 mg/kg in 0.5 mL） to simulate a single attack of ARDS, or intraperitoneally injected with a small dose of LPS （1 mg/kg） followed by tracheal instillation with median dose of LPS （5 mg/kg） to establish a ＂two-hit＂ model. Rats in each group were monitored by arterial blood gas analysis and visual inspection for three consecutive days. Arterial blood gas values, lung wet/dry weight ratio and pathological pulmonary changes were analyzed to determine the effects of each ALI/ARDS model. Concentrations of TNF-α, IL-1 and IL-10 in the bronchoalveolar lavage fluid （BALF） and blood plasma were meastired by using enzyme-linked immunosorbent assays （ELISA）. Our resulsts showed that single LPS-stimulation, whether through intravenous injection or tracheal instillation, could only induce ALl and temporary hypoxemia in rats. A two-hit LPS stimulation induces prolonged hypoxemia and specific pulmonary injury in rats, and is therefore a more ideal approximation of ARDS in the animal model. The pathogenesis of LPS two-hit-induced ARDS is associated with an uncontrolled systemic inflammatory response and inflammatory injury. It is concluded that the rat ARDS model produced by our LPS two-hit method is more stable and reliable than previous models, and closer to the diagnostic criteria of ARDS, and better mimics the pathological process of ARDS.

Expression of Angiotensin Ⅱ and Aldosterone in Radiation-induced Lung Injury

Objective Radiation-induced lung injury （RILl） is the most common, dose-limiting complication in thoracic malignancy radiotherapy. Considering its negative impact on patients and restrictions to efficacy, the mechanism of RILl was studied. Methods Wistar rats were locally irradiated with a single dose of 0, 16, and 20 Gy to the right half of the lung to establish a lung injury model. Two and six months after irradiation, the right half of the rat lung tissue was removed, and the concentrations of TGF-[31, angiotensin II, and aldosterone were determined via enzyme-linked immunosorbent assay. Results Statistical differences were observed in the expression levels of angiotensin II and aldosterone between the non-irradiation and irradiation groups. Moreover, the expression level of the angiotensin II-aldosterone system increased with increasing doses, and the difference was still observed as time progressed. Conclusions Angiotensin II-aldosterone system has an important pathophysiological function in the progression of RILI.

Effects of Hyperoxia on Mitochondrial Multienzyme Complex Ⅲ and Ⅴ in Premature Newborn Rat Lung

To investigate the effects of hyperoxia on mitochondrial multienzyme complex Ⅲ （cytochrome, Cytb） and Ⅴ （ATPase6, 8） in premature newborn rat lung, the 1-day-old preterm SD rats were randomly assigned to hyperoxia group and air group, The rats in hyperoxia group were continuously exposed to 85% oxygen and those in air group to room air. After 1, 4, 7, 10, 14 day（s） of exposure, these rats were killed, total lung RNA was extracted and Cytb, ATPase6, 8 mRNA were detected by reverse transcription polymerase chain reaction （RT-PCR）. Western blotting was used to detect the expression of Cytb protein in lung tissue. The results showed that compared with air group, Cytb mRNA expression was significantly increased （P〉0,05） after 1, 4 day（s） of exposure. The general tendency decreased after 7 days, and its expression became weak but difference in mRNA expression between the two groups was not significant （P〉0.05）. ATPase6 mRNA expression was significantly increased 1 day after the exposure （P〈0.05） and did not show any significant change 4, 7, 10 days after the exposure （P〉0.05）. At the 14th day, ATPase6 mRNA expression was significantly increased （P〈0.05）, ATPase8 mRNA expression did not show any significant change 1, 4, 10 day（s） after the exposure （P〉0.05）, At the 7th and 14th day, ATPase8 mRNA expression was significantly increased （P〈0.05）. Western blotting showed that Cytb protein expression was increased 1,4 day（s） after the exposure, but the difference between the two groups was not significant （P〉0.05）. The general tendency was decreased after 7 days, and its expression became weak but difference was not significant 7, 10 days after the exposure （P〉0.05）. At day 14 its expression became significantly weak （P〈0.05）. We are led to conclude that exposure to high concentrations of oxygen can significantly change the expression of Cytb and ATPase6, 8, which results in uncoupling of oxidative phosphorylation in mitochondrial respiration chain, and plays an important role in the mechanism of hyperoxia-induced lung injury.

Effects of Hyperoxia on Cytoplasmic Thioredoxin System in Alveolar Type Epithelial Cells of Premature Rats

This study investigated the effects of hyperoxia on dynamic changes of thioredoxin-1 （Trx1） and thioredoxin reductase-1 （TrxR1） in alveolar type Ⅱ epithelial cells （AECⅡ） of premature rats. Pregnant Sprague-Dawley rats were sacrificed on day 19 of gestation. AECⅡ were isolated and purified from the lungs of premature rats. When cultured to 80% confluence, in vitro cells were randomly divided into air group and hyperoxia group. Cells in the hyperoxia group were continuously exposed to 95% O2/5% CO2 and those in the air group to 95% air/5% CO2. After 12, 24 and 48 h, cells in the two groups were harvested to detect their reactive oxygen species （ROS）, apoptosis, TrxR1 activity and the expressions of Trx1 and TrxR1 by corresponding protocols, respectively. The results showed that AECⅡ exposed to hyperoxia generated excessive ROS and the apoptosis percentage in the hyperoxia group was increased significantly at each time points as compared with that in the air group （P0.001）. Moreover, TrxR1 activity was found to be markedly depressed in the hyperoxia group in comparison to that in the air group （P0.001）. RT-PCR showed the expressions of both Trx1 and TrxR1 mRNA were significantly increased in AECⅡ exposed to hyperoxia for 12 and 24 h （P0.01）, respectively. At 48 h, the level of Trx1 mRNA as well as that of TrxR1 mRNA in the hyperoxia group was reduced and showed no significant difference from that in the air group （P0.05）. Western blotting showed the changes of Trx1 protein expressions in the hyperoxia group paralleled those of Trx1 mRNA expressions revealed by RT-PCR. It was concluded that hyperoxia can up-regulate the protective Trx1/TrxR1 expressed by AECⅡ in a certain period, however, also cause dysfunction of the cytoplasmic thioredoxin system by decreasing TrxR1 activity, which may contribute to the progression of oxidative stress and cell apoptosis and finally result in lung injury.

Effects of anisodamine on pulmonary α_1-adrenergic receptor and phospholipase A, in acute lung injury

Objective: To imastigate the effects of anisodamine on pulmonary α1- adrenergic receptor andphospholipase A, in acute lung injurg. Methods: Change of α1--adrenergic receptor (al AR ) in lung tissllesduring endotoxin--induced rat acute lung injury was measured with radioligand biding assay. The effects ofanisodamine on pulmonary α1--AR and phospholipase A2 (PLA2 ) were observed. Results: 1. 4 h after theendotoxin injection, there was a significant decrease in the maximal binding capacity of α1--AR by 34% ascompared with the control group. meanwhile elevated activity of PLA2 in rat lung and reduction of thephospholipids content of cell membrane was found. 2. Anisodamine could attenuate endotoxin--induced acutelung injury in rats. Conclusion: This effect might be related to anisodamine’s blockage of α1--AR andsuppression of PLA2, prevention of membranous phospholipids from degradation. and the reduction ofarachidonic acid release.

沉默cFLIP在重症急性胰腺炎肺损伤中的作用机制研究

目的探讨沉默细胞型Fas相关死亡区域蛋白样白介素-1β转换酶抑制蛋白(cFLIP)对重症急性胰腺炎(SAP)导致的肺损伤的影响及其可能的作用机制。方法分别取12只SD大鼠,随机分为对照组、cFLIPL(或cFLIPS)siRNA1组、cFLIPL(或cFLIPS)siRNA2组和cFLIPL(或cFLIPS)siRNA3组,筛选抑制率最高的cFLIPL siRNA和cFLIPS siRNA。50只SD大鼠随机分成假手术组、模型对照组、cFLIP siRNA-NC组、cFLIPS siRNA组、cFLIPL siRNA组,每组各10只。通过胰胆管内逆行注射3%牛磺胆酸钠溶液建立SAP模型,建模成功后,cFLIPS siRNA、cFLIPL siRNA和cFLIP siRNA-NC组大鼠尾静脉注射对应siRNA溶液,其余组注射等量0.9%NaCl溶液。HE染色检测肺组织病理学变化;ELISA检测IL-6、IL-1β和TNF-α含量;全自动分析仪检测静脉血白细胞数、中性粒细胞数;流式细胞术检测中性粒细胞凋亡;Western blotting检测中性粒细胞RIP1和caspase-8蛋白表达。结果cFLIPL siRNA2组以及cFLIPS siRNA1组干扰效率最明显,因此选择这2组进行后续实验(后续称为cFLIPL siRNA组和cFLIPL siRNA组)。与模型对照组大鼠相比,cFLIPL siRNA组和cFLIPS siRNA组大鼠肺泡结构损伤减轻,肺泡壁变薄,炎症细胞浸润减少;与模型对照组相比,cFLIPL siRNA组和cFLIPS siRNA组IL-6、IL-1β和TNF-α含量均明显降低,静脉血白细胞数、中性粒细胞数明显降低,中性粒细胞凋亡率明显升高,cFLIPL、cFLIPS和RIP1蛋白表达量明显降低,caspase-8蛋白表达量明显升高;以上差异均具有统计学意义(P<0.05)。结论本研究结果表明,靶向沉默cFLIP可能通过上调caspase-8和抑制RIP1的表达,促进中性粒细胞凋亡,减少炎症介质IL-6、IL-1β和TNF-α释放,抑制肺组织中的中性粒细胞浸润,缓解SAP导致的肺损伤,在SAP中发挥保护作用。

建立急性高原低氧肺组织损伤雄性大鼠模型并探讨高原低氧肺组织损伤机制

目的摸索相关参数建立急性高原低氧肺组织损伤雄性大鼠模型并探讨高原低氧肺组织损伤机制。方法1.建立急性高原低氧肺组织损伤雄性大鼠模型的方法:采用随机数字表法将雄性大鼠分为5组,即空白对照组,高原低氧6h组、24h组、48h组、72h组,适应性喂养7 d后进低压氧舱(模拟海拔7000 m),以肺组织纹理模糊、肺泡壁变厚、肺泡间隔增宽判断造模成功。2.探讨高原低氧肺损伤机制的方法:分别比较各组大鼠动脉血血气分析(ABG)结果、肺组织血管紧张素II(Ang II)含量、肺组织内皮素1(ET-1)含量和肺组织血管紧张素转化酶(ACE)m RNA的表达情况及肺组织超微结构,并作相关性分析。结果1.各组雄性大鼠ABG相关指标的变化:与对照组比较,高原低氧6 h、24 h、48 h、72 h组氧分压(PaO_(2))、动脉血氧饱合度(SaO_(2))、二氧化碳分压(PaCO_(2))和酸碱度(p H)值均下降,在一定时间范围内缺氧时间越长下降越明显(P<0.05)。2.各组雄性大鼠肺组织形态学的变化:与对照组比较,光镜下可见高原低氧各组出现不同程度的肺纹理模糊、肺泡壁增厚、肺泡间隔增宽;随着缺氧时间延长,肺组织损伤逐渐加重。3.各组雄性大鼠肺组织AngⅡ、ET-1含量变化:与对照组比较,高原低氧各组大鼠肺组织AngⅡ、ET-1含量明显升高(P<0.01),在一定时间范围内随缺氧时间延长而增加,72 h组达到高峰。4.各组雄性大鼠肺组织ACE m RNA表达比较:与对照组比较,高原低氧各组大鼠肺组织ACE m RNA表达均上调,6h组升高显著,72h组达到峰值(P<0.01)。结论利用低压氧舱模拟海拔7000 m环境,可以有效建立大鼠肺组织损伤模型;高原低氧肺损伤机制可能与ET-1、AngⅡ及ACE m RNA的表达水平上调,肾素-血管紧张素系统(RAS)失衡有关。

甲基莲心碱通过调控NF-κB信号通路减轻脓毒症大鼠急性肺损伤

【目的】探讨甲基莲心碱对脓毒症大鼠急性肺损伤的治疗作用及机制。【方法】采用盲肠结扎穿刺(GLP)法制备脓毒症大鼠模型,造模成功后,将大鼠分为模型组,甲基莲心碱低、高剂量组和甲基莲心碱高剂量+PMA[核转录因子κB(NF-κB)激活剂佛波酯]组,同时设置假手术组,每组15只。术后6 h,给予相应干预,连续2 d。采用苏木素-伊红(HE)染色观察肺组织形态学改变,并进行损伤病理评分;检测肺组织湿干质量比;血气分析仪检测动脉血氧分压(PaO_(2))和动脉血二氧化碳分压(PaCO_(2))水平;酶联免疫吸附法(ELISA)测定支气管肺泡灌洗液(BALF)中肿瘤坏死因子α(TNF-α)、白细胞介素1β(IL-1β)、白细胞介素6(IL-6)水平;Western Blot法检测肺组织中NF-κB p65、磷酸化NF-κB(p-NF-κB)p65(Ser536)、环氧合酶2(COX-2)蛋白表达水平。【结果】与假手术组比较,模型组大鼠肺组织损伤严重,肺组织损伤病理评分、湿干质量比及PaCO_(2)水平显著升高(P<0.01),PaO_(2)水平显著降低(P<0.01),BALF中TNF-α、IL-1β、IL-6水平以及肺组织中p-NF-κB p65/NF-κB p65比值、COX-2蛋白表达水平显著升高(P<0.01);与模型组比较,甲基莲心碱低、高剂量组大鼠肺组织损伤明显改善,肺组织损伤病理评分、湿干质量比及PaCO_(2)水平显著降低(P<0.05或P<0.01),PaO_(2)水平显著升高(P<0.05或P<0.01),BALF中TNF-α、IL-1β、IL-6水平以及肺组织中p-NF-κB p65/NF-κB p65比值、COX-2蛋白表达水平显著降低(P<0.05或P<0.01)。然而,PMA干预后,甲基莲心碱对脓毒症大鼠肺组织损伤的改善作用被明显逆转(P<0.01)。【结论】甲基莲心碱可改善大鼠脓毒症急性肺损伤及肺功能,其作用可能与抑制NF-κB信号通路激活,进而减少体内炎症因子释放有关。

槐定碱调节Hippo-YAP信号通路对急性呼吸窘迫综合征大鼠的改善作用

目的:探究槐定碱(SRI)对急性呼吸窘迫综合征(ARDS)大鼠的改善作用,并探究其作用机制。方法:随机取10只SD大鼠为空白组。50只SD大鼠采用脂多糖(LPS)气管滴注法构建ARDS大鼠模型。将造模成功大鼠随机分为模型组、SRI低剂量组、SRI中剂量组、SRI高剂量组、维替泊芬(Verteporfin)+SRI高剂量组,每组10只。造模2 h后SRI低、中、高剂量组分别予低(2 mg/kg)、中(6 mg/kg)、高(12 mg/kg)剂量SRI腹腔注射,Verteporfin+SRI高剂量组在腹腔注射Verteporfin(100 mg/kg)的基础上予SRI腹腔注射(12 mg/kg)。空白组和模型组腹腔注射等体积生理盐水。给药10 h后检测大鼠血氧分压(PaO_(2))、氧指数[PaO_(2)/吸入氧浓度(FiO_(2))]和肺湿/干(W/D)比,HE染色观察肺组织病理变化并进行病理损伤评分,酶联免疫吸附(ELISA)法检测肺泡灌洗液(BALF)中肿瘤坏死因子-α(TNF-α)、白细胞介素(IL)-1β和IL-10的水平,BCA检测BALF中总蛋白水平,姬姆萨染色检测BALF中巨噬细胞和中性粒细胞数量,ELISA法检测肺组织丙二醛(MDA),比色法检测肺组织超氧化物歧化酶(SOD)活性,荧光法检测肺组织髓过氧化物酶(MPO)活性,Western blotting检测肺组织Hippo-YAP通路蛋白表达。结果:与空白组比较,模型组大鼠肺组织结构破坏,大量炎症细胞浸润;与模型组比较,SRI低、中、高剂量组肺组织结构有所恢复;与SRI高剂量组比较,Verteporfin+SRI高剂量组肺组织损伤加重,肺泡肿胀、变性,炎症细胞浸润明显。模型组大鼠PaO_(2)、PaO_(2)/FiO_(2)值低于空白组,W/D比、病理损伤评分高于空白组(P<0.05);SRI低、中、高剂量组PaO_(2)、PaO_(2)/FiO_(2)值高于模型组,W/D比、病理损伤评分低于模型组(P<0.05);Verteporfin+SRI高剂量组PaO_(2)、PaO_(2)/FiO_(2)值低于SRI高剂量组,W/D比、病理损伤评分高于SRI高剂量组(P<0.05)。模型组大鼠BALF中TNF-α、IL-1β、IL-10、总蛋白水平及巨噬细胞计数、中性粒细胞计数高于空白组(P<0.05);SRI低、中、高剂量组大鼠BALF中TNF-α、IL-1β、总蛋白水平及巨噬细胞计数、中性粒细胞计数低于模型组,BALF中IL-10水平显高于模型组(P<0.05);Verteporfin+SRI高剂量组大鼠BALF中TNF-α、IL-1β、总蛋白水平和巨噬细胞计数、中性粒细胞计数高于SRI高剂量组,BALF中IL-10水平低于SRI高剂量组(P<0.05)。模型组大鼠肺组织MDA、MPO、p-YAP蛋白相对表达量及p-LATS1/LATS1高于空白组,SOD活性及YAP、TEAD1蛋白相对表达量低于空白组(P<0.05);SRI低、中、高剂量组大鼠肺组织MDA、MPO、p-YAP蛋白相对表达量及p-LATS1/LATS1低于模型组,SOD活性及YAP、TEAD1蛋白相对表达量高于模型组(P<0.05);Verteporfin+SRI高剂量组大鼠肺组织MDA、MPO、p-YAP蛋白相对表达量及p-LATS1/LATS1高于SRI高剂量组,SOD活性及YAP、TEAD1蛋白相对表达量低于SRI高剂量组(P<0.05)。结论:SRI能抑制ARDS大鼠炎症反应和氧化应激,其作用机制可能与激活Hippo-YAP信号通路有关。

石菖蒲挥发油对宫内感染所致新生鼠肺损伤的作用

目的探讨石菖蒲挥发油(volatile oil of Acorus tatarinowii,VOAT)对宫内感染所致新生鼠肺损伤的作用及可能的机制。方法随机选取6只妊娠15 d的SD大鼠作为对照组,子宫颈内注射大肠埃希菌构建宫内感染大鼠模型,并随机分为模型组及VOAT低、中、高剂量组,每组6只,次日给药,其中VOAT低、中、高剂量组大鼠分别灌胃VOAT 5、10、20 g·kg^(−1)·d^(−1),模型组和对照组大鼠灌胃等量生理盐水,连续给药直至分娩。记录各组新生鼠胎龄;测定新生鼠肺指数;用酶联免疫吸附试验(enzymelinked immunosorbent assay,ELISA)测定新生鼠血清白细胞介素(interleukin,IL)-21和IL-6、IL-1β水平;苏木素伊红(hematoxylin-eosin,HE)染色检测新生鼠肺组织病理学变化;实时荧光定量聚合酶链式反应(quantitative real-time polymerase chain reaction,RT-qPCR)检测肺组织中IL-21、IL-21R mRNA的相对表达水平;Western blotting检测肺组织中IL-21、IL-21R、STAT3、p-STAT3蛋白的相对表达量。结果与对照组比较,模型组及VOAT低、中、高剂量组新生鼠胎龄缩短,肺指数降低,血清IL-21、IL-6及IL-1β水平,肺组织中IL-21、IL-21R mRNA的相对表达量及IL-21、IL-21R和p-STAT3蛋白的相对表达量均升高(P<0.05),并出现不同程度的炎性细胞浸润、肺泡壁增厚、肺泡腔变大、结构紊乱等病理学变化;与模型组比较,VOAT低、中、高剂量组新生鼠肺指数升高,血清IL-21、IL-6及IL-1β水平,肺组织中IL-21、IL-21R mRNA的相对表达量及IL-21、IL-21R和p-STAT3蛋白的相对表达量均降低(P<0.05),肺组织病理损伤有不同程度减轻;VOAT对宫内感染所致新生鼠肺损伤的作用效果呈剂量依赖性(P<0.05)。结论VOAT可减轻宫内感染所致新生鼠肺损伤,其作用机制可能与抑制IL-21/STAT3通路激活、降低机体炎症水平有关。