芹菜素对LPS诱导小鼠急性肺损伤的保护作用

[目的]揭示芹菜素的抗炎作用机制.[方法]通过建立小鼠模型,研究芹菜素对LPS诱导急性肺损伤的保护作用.[结果]芹菜素可以降低LPS诱导的肺组织损伤和肺组织MPO活性.与LPS组相比,芹菜素治疗组可以显著降低肺泡盥洗液中TNF-α、IL-1β、IL-6的表达水平,并抑制NF-κB信号通路的激活.[结论]芹菜素可以通过抑制NF-κB的激活并降低炎性细胞因子的水平,从而对小鼠急性肺损伤产生抗炎保护作用.     

饲料中不同赖氨酸水平对急性高温胁迫后刺参非特异性免疫酶活性的影响

[目的]研究饲料中不同赖氨酸水平对急性高温胁迫后刺参非特异性免疫酶活性的影响。[方法]试验配制赖氨酸含量分别为0.28%(Ⅰ组)、0.64%(Ⅱ组)、1.19%(Ⅲ组)、1.89%(Ⅳ组)和2.23%(Ⅴ组)的5种刺参试验饲料,用以投喂体质量(1.55±0.01)g的刺参。56 d养殖试验(养殖期间水温控制在(18±1)℃)结束后,对刺参进行急性高温(28℃)刺激,1.5 h后测定其体腔液酸性磷酸酶(ACP)、碱性磷酸酶(AKP)、过氧化氢酶活性(CAT)和总抗氧化能力(T-AOC)。[结果]高温刺激下,随着赖氨酸添加量的提高,刺参体腔液中的ACP活性呈先升高后下降的趋势。当赖氨酸含量为1.89%时ACP活性最高,其AKP和T-AOC活性的变化趋势与ACP基本相同。CAT活性随着赖氨酸含量的增加而升高,当赖氨酸含量为1.19%时CAT活性达到最大值,此后呈现下降趋势。[结论]饲料中添加适量的赖氨酸能改善刺参体腔液非特异性免疫酶活性,增强其对急性高温胁迫的适应性并提高其存活率。刺参饲料中赖氨酸的适宜添加范围为1.19%~1.89%。     

Cu2+和Pb2+对石蚕蛾幼虫的急毒性研究

[目的]研究Cu~(2+)和Pb~(2+)对石蚕蛾幼虫的急毒性效应和安全浓度。[方法]从广西十万大山保护区采集石蚕蛾(Stenopsyche marmorata)幼虫,采用静水生物毒性试验法进行重金属离子Cu~(2+)和Pb~(2+)对其的急毒性试验。采用概率单位法分别计算Cu~(2+)和Pb~(2+)对石蚕蛾幼虫的半致死浓度和安全浓度。[结果]Cu~(2+)对石蚕蛾幼虫的24、48、72、96 h的半致死浓度(LC50)分别为123.651、112.975、84.536和70.509 mg/L,Pb~(2+)对石蚕蛾幼虫的24、48、72、96 h的半致死浓度(LC50)分别为49.138、41.878、30.735和29.245 mg/L。Cu~(2+)和Pb~(2+)对石蚕蛾幼虫的安全浓度分别为7.051和2.925 mg/L。[结论]研究结果可为将石蚕蛾幼虫用作水体重金属污染指示生物提供科学依据。     

多菌灵杀菌剂对青海弧菌和斑马鱼的急性毒性研究

[目的]研究农药对农田环境及非靶标有益生物的影响。[方法]选取青海弧菌Q67和斑马鱼作为受试生物,研究多菌灵杀菌剂对其的急性毒性,从而初步评价该杀菌剂农业生产应用中对水生生物的潜在风险。[结果]22%多菌灵杀菌剂对青海弧菌Q67的EC_(50)为7.70 mg/L,pEC_(50)为2.11;22%多菌灵杀菌剂对斑马鱼的24、48、72、96 h LC_(50)分别为8.53、8.39、8.07和7.64 mg/L;斑马鱼的安全浓度为0.76 mg/L。[结论]根据《化学农药环境安全评价试验准则》"鱼类急性毒性试验"对鱼类毒性评价标准,判断22%多菌灵杀菌剂对斑马鱼的毒性属中毒。     

Mechanisms for protection of berberine against LPS-induced acute lung injury in mice

AIM:To investigate the mechanisms by which berberine attenuates LPS-induced acute lung injury, and provide a new strategy for the treatment of the lung injury due to LPS. METHODS:BALB/c mice were randomly assigned into three groups (control, LPS group, and berberine treatment group). Mice were administered intragastrically with distilled water (0.1 mL/10 g) or neutral sulfate berberine (50 mg/kg) once a day for 3 days, 1 h after intragastrical treatment on day 3, LPS (20 mg/kg) or normal saline was injected intraperitoneally (ip). All animals were sacrificed 12 h after LPS injection, the left lung tissue sections were prepared for histology analysis and the right lung were used to determine the ratio of wet to dry lung tissue weight (W/D). In another experiment, bronchoalveolar lavage fluid (BALF) was collected, and then the total protein content, and the amounts of white blood cells (WBC) and polymorphonuclear neutrophils (PMN) in BALF were determined. Furthermore, the phosphorylation of cytosolic phospholipase A₂ (cPLA₂) was detected with immunohistochemical analysis by using phospho-cPLA2(Ser505) antibody, and the contents of thromboxane B₂ (TXB₂) in BALF, malondialdehyde (MDA) in the lungs, and activity of superoxide dismutase (SOD) in lung tissues were also determined.RESULTS:LPS induced acute lung injury, activated cPLA₂, and increased TXB₂ content in the BALF and MDA level in the lung tissue. The pretreatment with berberine significantly attenuated lung injury, lung edema and protein leakage induced by intraperitoneal injection of LPS. The expression of phospho-cPLA₂ in the lung tissues and TXB₂ content in the BALF in the berberine treatment group were lower than those in LPS group (P<0.05). In addition, the content of MDA in the lung tissue was lower in the berberine treatment group than LPS group (P<0.05), but there was no significant difference in activity of lung SOD between the berberine treatment and LPS group (P>0.05). CONCLUSION:Pretreatment with berberine remarkably reduces the LPS-induced lung injury, which is, at least in part, through inhibiting phosphorylation of cPLA₂ and decreasing lipid peroxidation. These findings provide a new strategy for the prevention and treatment of LPS-induced acute lung injury.     

Porcine surfactant in treatment of LPS-induced early-stage acute lung injury in rats

AIM: To evaluate the therapeutic efficacy of intratracheal instillation of porcine pulmonary surfactant (PPS) in rats with lipopolysaccharides (LPS)-induced early-stage ALI in this study.METHODS: SD rats weighing 200 g-300 g were randomly divided into 4 groups: LPS (1.5 mg·kg-1)+saline,LPS+PPS 100 mg·kg^-1,LPS+PPS 150 mg·kg^-1,LPS+PPS 200 mg·kg^-1.The PaO₂ and PaCO₂,as well as survival rate of rats were examined for 6 h after the start of PPS-instillation.Then,rats were killed and lungs were immediately removed for lung index (LI) and histological analysis.The bronchoalveolar lavage fluid (BALF) was collected for measurement of total protein (TP) contents,TNF-α level and white blood cell(WBC) numbers.RESULTS: Significantly increased PaO₂,reduced mortality rate,decreased total protein and TNF-α contents in BAL,as well as lung index and meliorated histological appearance were observed in three PPS-treated groups compared with group given saline after LPS (P<0.05).The therapeutic effect in PPS150 and PPS200 groups was better than that in PPS100 group.CONCLUSION: Intratracheal PPS instillation provides protective effect on acute lung injury in rats induced by LPS.     

氧化沉降条件下草甘膦对福寿螺的急性毒性效应

【目的】探究草甘膦与H₂O₂复合污染条件下草甘膦对福寿螺Pomacea canaliculata的急性毒性效应。【方法】采用静水式生物测试法,采集田间生长均匀一致的成年福寿螺,使其暴露于不同浓度草甘膦和近似广州地区降水H₂O₂浓度(50μmol·L^-1)的水体中。研究氧化沉降条件下草甘膦对福寿螺生境的水质部分指标和急性毒性效应的影响。【结果】水体水质指标中,氧化还原电位（Oxidation-reduction potential,ORP）随暴露时间增加而上升,由330 mV上升至540 mV左右;pH随暴露时间增加,不同处理有上升也有下降的趋势,最终都维持在7.0～8.5;溶解氧（Dissolved oxygen,DO）在8.5～16.0 mg·L^-1之间,无固定变化规律;这3个指标都维持在福寿螺生长能适应的范围内。急性毒性试验表明,草甘膦对福寿螺为低毒,在有或无H₂O₂添加时其48 h的半致死浓度(LC     

Salivary testosterone measurements in growing pigs: validation of an automated chemiluminescent immunoassay and its possible use as an acute stress marker

This study aimed to validate the use of an automated chemiluminescent immunoassay analyser for salivary testosterone measurements in growing pigs and study how circadian pattern during daytime and stress can influence its values. The test method had intra- and inter-assay coefficient of variation lower than 10%. The method showed good linearity and recovery, and detection limits were low enough to detect salivary testosterone levels. No significant differences were observed in testosterone concentrations at different sampling time, and age and gender did not influence circadian pattern. In addition, this assay was used to quantify testosterone in two models of acute stress and, in both cases, significant increases (P < 0.01) in salivary testosterone were detected. Therefore, the automated assay system tested for porcine testosterone determinations would be suitable for its use in saliva samples and, furthermore, salivary testosterone levels could be used as a possible marker of acute stress in pigs.