三氯乙烯及其代谢产物的豚鼠皮肤致敏作用研究

目的研究三氯乙烯(TCE)及其代谢产物三氯乙酸(TCA)、三氯乙醇(TCOH)对豚鼠皮肤致敏作用。方法选用体重250~300 g SPF级白化Hartley豚鼠,雌雄各半,按OECD豚鼠最大值实验法,用TCE、TCOH、TCA分别对豚鼠进行皮内注射和涂皮结合法致敏,并设空白对照组及阳性对照组(二硝基氯苯,DNCB),观察各组动物皮肤的红斑和水肿等情况,计算致敏率。在终末激发24 h后用乙醚麻醉动物后处死,取涂抹部位及邻近皮肤进行病理学检查。结果 TCE、TCOH、TCA致敏率分别为80%、35%、0%,TCE致敏阳性组豚鼠皮肤可见中度弥漫的红斑、轻度水肿;TCOH致敏阳性组豚鼠皮肤可见散在或小块红斑。病理检查显示TCE致敏阳性组豚鼠表皮棘细胞层明显增厚,真皮乳头层及网织层可见淋巴细胞、嗜酸性粒细胞弥散或聚集性浸润及毛细血管轻度充血;TCOH致敏阳性组豚鼠表皮棘细胞层轻度增厚,真皮乳头层及网织层嗜酸性粒细胞弥散或聚集性浸润,夹杂少量淋巴细胞。结论TCE、TCOE可使豚鼠皮肤发生过敏性改变,TCE是强致敏物,TCOH为中度致敏物,TCA未见致敏作用。     

三氯乙烯诱发豚鼠过敏性皮炎的免疫学效应

目的研究三氯乙烯(TCE)诱发豚鼠过敏性皮炎的免疫学效应。方法采用豚鼠最大值法建立TCE致敏动物模型,应用ELISA双抗体夹心法定量检测血清中IgG含量;用MTT法测定刀豆蛋白A刺激下T淋巴细胞的增殖转化功能,用乳酸脱氢酶释放法测定NK细胞功能。结果TCE的致敏率为667%,属强致敏物。TCE致敏豚鼠血清总IgG含量明显高于阴性对照组(P<005)。TCE致敏豚鼠脾T淋巴细胞增殖转化功能及NK细胞对瘤细胞的杀伤活性与对照组相比无显著性差异(P>005)。结论体液免疫在TCE诱发过敏性皮炎过程中发挥一定的作用。在本染毒方式和染毒剂量下,未见TCE对豚鼠T淋巴细胞和NK细胞活性的影响。     

三氯乙烯致敏豚鼠单核淋巴细胞中β-arrestin蛋白表达和核转录因子及激活蛋白-1活性的研究

目的 测定三氯乙烯(TCE)致敏豚鼠外周血单核淋巴细胞(PBMC)中β-arrestin蛋白表达水平,核转录因子(NF-κB)和激活蛋白-1(AP-1)活性以及血清中肿瘤坏死因子(TNF-α)水平,探讨TCE致敏中免疫反应调节机制.方法 根据豚鼠最大值试验方法,用TCE对豚鼠进行处理(TCE处理组,14只),同时设立空白对照(5只)和DNCB阳性对照(7只),对受试动物进行皮肤反应评分,据此判断致敏与否,并把TCE处理组分为TCE致敏组和TCE未致敏组.提取豚鼠外周血单核细胞(PBMC),用免疫蛋白印迹(Western bloting)法检测β-arrestin蛋白表达水平,用电泳迁移率试验(EMSA)方法检测NF-κB和AP-1活性.酶联免疫吸附(ELISA)试剂盒检测血清中TNF-α水平.结果 空白对照组豚鼠未见红斑或水肿,TCE组的部分豚鼠皮肤出现红斑和水肿,致敏率为71.4%,DNCB处理组所有动物皮肤出现明显红斑或水肿,致敏率为100%.空白对照、TCE未致敏组、TCE致敏组和DNCB处理组豚鼠PBMC中β-arrestin蛋白表达水平比较,差异无统计学意义(P>0.05).与空白对照组和TCE未致敏组相比,TCE致敏组NF-κB活性明显升高,且差异有统计学意义(P<0.05);而各组豚鼠AP-1活性比较,差异无统计学意义(P>0.05).TCE致敏组血清中TNF-α水平[(55.485+8.732)pg/ml]较空白对照组[(32.118±12.550)pg/ml]明显升高,差异有统计学意义(P<0.05).结论 以TCE致敏豚鼠β-arrestin和AP-1可能没被激活,而NF-κB被明显激活且在TCE致敏免疫反应中发挥着调节作用.     

IL-6和IL-8在三氯乙烯致敏豚鼠血清中的变化

目的通过豚鼠致敏最大值试验(guinea pig maximization test,GPMT)方法建立豚鼠致敏模型,检测并比较TCE致敏豚鼠与未致敏豚鼠血清中IL-6和IL-8的水平,探讨IL-6和IL-8在三氯乙烯(TCE)过敏性皮炎中的作用。方法将豚鼠随机分为空白对照组,溶剂(橄榄油)对照组,DNCB阳性对照组和TCE处理组。采用GPMT法建立豚鼠致敏模型。根据致敏结果及末次激发后采血的不同时点将TCE处理组分为TCE未致敏24h组,TCE致敏24h组,TCE未致敏72h组,TCE致敏72h组。用ELISA试剂盒测定血清中IL-6和IL-8的含量。结果DNCB组致敏率为100%,TCE组致敏率为62.1%。溶剂对照组与空白对照组差异均无统计学意义。与溶剂对照组相比,TCE未致敏24h组IL-6水平降低,差异有统计学意义(P<0.05),TCE未致敏72h组与TCE未致敏24h组相比,IL-6水平明显升高,差异有统计学意义(P<0.05)。与溶剂对照组相比,TCE未致敏72组IL-8水平明显降低,差异有统计学意义(P<0.05)。结论血清中细胞因子IL-6和IL-8水平在TCE诱导的致敏组和未致敏组豚鼠间...     

三氯乙烯致敏豚鼠肾脏丙二醛水平和超氧化物歧化酶活力变化

目的 研究三氯乙烯(TCE)致敏豚鼠肾脏中丙二醛(MDA)水平和超氧化物歧化酶(SOD)活力的变化,探讨TCE对豚鼠肾脏的氧化应激水平的影响.方法 50只豚鼠随机分为空白对照组、溶剂(橄榄油)对照组、TCE处理组.根据豚鼠最大值实验(GPMT)方法处理豚鼠.按照<化学品毒性鉴定技术规范>的评分标准对动物的皮肤反应进行评分,评分≥1且总致敏率＞9%的判为致敏.在末次激发后24、72 h和1周3个时点分批采血,测定血清中尿素氮(BUN)、肌酐(Cr)水平:取肾脏组织测定MDA水平以及总SOD(T-SOD)活力.结果 TCE组致敏率为65.0%,与溶荆对照组相比较,TCE致敏组24 h血清BUN、Cr都明显升高(P＜0.05).与溶剂对照组相比,TCE致教24 h组MDA水平明显上升(P＜0.05);TCE致敏组与未致敏组比较,24 h组MDA水平差异有统计学意义(P＜0.05).TCE致敏组SOD活力比溶剂对照组明显降低(P＜0.05).各时点问有下降或升高的趋势但是差异无统计学意义;24、72 h致敏组SOD活力较非致敏组低,差异有统计学意义(P＜0.05).结论 TCE诱导的致敏豚鼠肾脏有一定程度的损伤,其中氧化应激发挥一定作用.     

T、B淋巴细胞及细胞因子在三氯乙烯诱发过敏反应中的作用

目的利用三氯乙烯(TCE)染毒的小鼠模型,研究T、B淋巴细胞及细胞因子在TCE诱发过敏反应中的作用。方法以皮肤接触同时结合吸入对12只小鼠进行致敏处理,6周后耳部涂抹TCE进行激发。以耳肿胀系数作为评价小鼠过敏反应的指标;分离脾细胞体外培养,采用噻唑蓝(MTT)法测定脾淋巴细胞抗原特异性增殖反应;酶联免疫吸附测定(ELISA)方法测定细胞培养上清液中IgG和白介素-4(IL-4)、γ型干扰素(IFN-γ)水平;应用流式细胞技术进行淋巴细胞亚群分析。结果TCE致敏组小鼠脾淋巴细胞加入TCE体外培养后,细胞存活率明显高于溶剂对照组[(79±10)%vs(63±11)%,P<0·05];细胞培养上清液中IgG水平(与二甲基亚砜对照孔比较的相对值)在两组间比较差异有显著性[(70±5%)vs(53±6)%,P<0·01]。流式细胞分析结果显示,TCE致敏组脾淋巴细胞与TCE共培养后,CD3 T细胞占总淋巴细胞的比例[(41·6±4·4)%]及CD4 /CD8 (2·1±0·6)与对照组比较[分别为(39·4±4·0)%和(2·3±0·9)],差异无显著性(P>0·05)。TCE致敏组小鼠激发时未见耳肿胀,然而TCE致敏组小鼠IFN-γ/IL-4比值(0·54±0·12)明显低于溶剂对照组(0·90±0·22,P<0·01)。结论TCE能够诱导T淋巴细胞的增殖活化,分泌Th2型细胞因子,并刺激B淋巴细胞分泌抗原特异性的IgG抗体。     

三氯乙烯致敏豚鼠皮肤组织中白细胞介素-1、-6和-8表达的研究

目的研究白细胞介素(IL)-1、IL-6和IL-8在三氯乙烯(TCE)致敏豚鼠皮肤组织中的表达情况,探讨TCE药疹样皮炎发病机制。方法将白色雌性豚鼠随机分成空白对照组、溶剂对照组、TCE实验组、2,4-二硝基氯苯(DNCB)阳性对照组,根据豚鼠最大值试验(GPMT)方法处理豚鼠,在终末激发后(依据致敏结果以及取材时点的不同,将TCE实验组以及DNCB阳性对照组分为TCE致敏组24 h、TCE致敏组72 h、TCE未致敏组24 h和TCE未致敏组72 h;DNCB组24 h和DNCB组72 h)进行皮肤反应评分,并采取皮肤组织,制成蜡块,采用Elivison二步法免疫组织化学法检测各组皮肤组织中IL-1、IL-6和IL-8的表达情况。结果根据皮肤反应评分≥1判断为致敏阳性,TCE实验组致敏率为62.1%;TCE致敏组24 h和TCE致敏组72 h的IL-1水平要显著高于溶剂对照组,且差异有统计学意义(P<0.05);同时TCE致敏组24 h与TCE未致敏组24 h比较、TCE致敏组72 h与TCE未致敏组72 h比较差异也有统计学意义(P<0.05),但IL-6和IL-8水平在各个组别和不同时间点之间差异无统计...     

三氯乙烯致敏豚鼠及IL-10表达的研究

目的研究细胞因子白细胞介素-10(IL-10)在三氯乙烯(TCE)致敏豚鼠表皮中的表达,探讨TCE药疹样皮炎发病机制。方法将白色雌性豚鼠随机分成空白对照组、溶剂对照组、TCE实验组、2,4—二硝基氯苯(DNCB)阳性对照组,根据豚鼠最大反应试验(guinea pig maximization test,GPMT)方法处理豚鼠,在终末激发后进行皮肤反应评分,皮肤反应评分≥1判断为致敏,依据致敏结果以及取材时间的不同将TCE实验组分为致敏组24 h、72 h和未致敏组24 h、72 h,DNCB阳性对照组24 h和72 h。无菌条件下取皮制成蜡块,采用Elivison二步法免疫组织化学法检测各组表皮中IL-10的表达情况。结果 TCE实验组致敏率为62.1%;TCE致敏24 h组和72 h组的IL-10水平高于溶剂对照组,且差异有统计学意义(P0.05);同时TCE致敏24 h组与TCE未致敏24 h组比较、TCE致敏72 h组与TCE未致敏72 h组比较,差异也有统计学意义(P0.05);TCE致敏24 h组与DNCB 24 h组比较,差异有统计学意义(P0.05)。结论 TCE对豚鼠皮肤具有致敏作用,IL-10在TCE药疹样皮炎发生过程中具有重要意义。     

三氯乙烯致敏豚鼠皮肤及血清中IL-17的测定

目的比较三氯乙烯(TCE)致敏豚鼠和未致敏豚鼠皮肤和血清中IL-17表达水平,探讨TCE药疹样皮炎新的发病机制。方法将豚鼠随机分为空白对照组,溶剂(橄榄油)对照组,TCE处理组。根据豚鼠最大值试验方法(Guinea Pig Maximization Test,GPMT)处理豚鼠。按照《化学品毒性鉴定技术规范》的评分标准对动物的皮肤反应进行评分,评分≥1的判为致敏。在末次激发后24 h,72 h,1周和2周分四批采血和皮肤组织,用ELISA试剂盒测定血清中IL-17的含量;将皮肤组织制成蜡块,采用Elivison二步法免疫组织化学法检测其IL-17的表达情况。结果根据皮肤反应评分判断致敏阳性,TCE处理组致敏率为70%。TCE处理组血清中IL-17的水平及皮肤组织免疫组化评分明显高于溶剂对照组,且差异有统计学意义(P<0.05);TCE处理组的不同时间段相比,IL-17的表达差异有统计学意义(P<0.05);在TCE处理组72h和1周两个时点,TCE致敏鼠IL-17的表达比相应的未致敏鼠高,差异有统计学意义(P<0.05)。结论 TCE可以诱导豚鼠致敏,IL-17在豚鼠致敏的过程中有重要意义。     

三氯乙烯致敏豚鼠体内循环免疫复合物的变化

目的检测循环免疫复合物(CIC)在三氯乙烯(TCE)致敏豚鼠体内含量的变化,探讨其可能的作用。方法选用体重250～300 g的白色雌性豚鼠,随机分成空白对照组、溶剂对照组、TCE处理组。根据豚鼠最大值试验(GPMT)方法处理豚鼠。分别在实验结束后24 h、72 h采血,检测血清中IgA/C3-CIC、IgG/C3-CIC和IgM/C3-CIC的浓度。结果 TCE处理组致敏率为65.38%;与溶剂对照组相比,TCE致敏组和TCE未致敏组的血清中IgA/C3-CIC、IgG/C3-CIC和IgM/C3-CIC的浓度均明显降低,差异有统计学意义(P<0.05)。结论 TCE处理组豚鼠血清中循环免疫复合物含量降低,可能提示其体液免疫发生改变。     

三氯乙烯致敏豚鼠体内转化生长因子-β、白细胞介素-10表达水平

目的研究抗炎性细胞因子转化生长因子-β(TGF-β)、白细胞介素(IL-10)在三氯乙烯(TCE)致敏豚鼠血清和皮肤中的水平,探讨TCE接触过敏性皮炎的发病机制。方法选用雌性豚鼠74只,随机分成空白对照组、溶剂对照组、TCE处理组,用豚鼠最大值实验方法建立动物致敏模型,并在终末激发后把致敏豚鼠和未致敏豚鼠分别分为24 h、72h、1周、2周组并在相应时间点采集血样。采用酶联免疫吸附法检测各组血清中TGF-β、IL-10水平,免疫组织化学法检测皮肤组织中TGF-β、IL-10的表达。结果 TCE处理组致敏率为68.8%。血清TGF-β水平检测,致敏72 h和1周组比致敏24 h组明显升高(P<0.05),致敏72 h、1周组高于未致敏同时点组(P<0.05);血清IL-10水平检测,致敏72 h组比致敏24 h组明显升高(P<0.05),致敏2周组显著下降(P<0.05),致敏72 h组高于未致敏72 h组(P<0.05)。皮肤组织中TGF-β、IL-10的表达,致敏72 h组高于致敏24 h组、致敏1周组显著高于致敏72 h组(P<0.05),致敏2周组降至最低,致敏72 h、1周组高于未致敏同时点组(P<0.05)。结论 TCE对豚鼠皮肤具有强致敏作用,TGF-β、IL-10在TCE接触过敏性皮炎发生过程中可能具有重要意义。     

三氯乙烯染毒对豚鼠肝功能与凋亡基因表达的影响

目的探讨使用三氯乙烯(TCE)染毒对豚鼠肝功能和肝细胞凋亡基因(BAX、BAD、Bc1-2)表达的影响。方法将24只豚鼠随机分为3组,采用豚鼠最大值法(GPMT),设立TCE实验组、阴性对照组、阳性对照组,用皮内注射的方式分别注射TCE、橄榄油、2,4-二硝基氯苯(DNCB),实验结束后观察动物皮肤改变,应用自动生化分析仪检测动物肝功能指标,用荧光定量PCR检测肝细胞凋亡基因表达水平。结果 TCE实验组和阳性对照组动物出现明显皮肤损害。TCE实验组动物血清中丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)、乳酸脱氢酶(LDH)活力明显高于阴性对照组(P0.05或P0.01)。肝细胞BAX、BAD的mRNA表达水平比阴性对照组显著升高,Bc1-2表达水平下降(P0.05或P0.01)。结论三氯乙烯可诱导豚鼠产生明显的皮肤变态反应,引起实验动物肝功能指标改变和肝细胞凋亡基因表达水平明显改变。     

Copper deficiency does not lead to taurine deficiency in rats

Copper deficiency has been reported to cause a decrease in urinary taurine excretion in rats. We determined whether Cu deficiency would decrease taurine status and the hepatic activities of cysteine dioxygenase (CDO) and/or cysteine sulfinic acid decarboxylase (CSAD) in rats. Ten weanling male rats were assigned to either a Cu-adequate (+Cu) or Cu-deficient (-Cu) group. All rats consumed a Cu-deficient purified diet and water ad-libitum for 16 wk. The water for the (+Cu) group contained 20 mg Cu/L as CuSO(4). At wk 16, the groups differed (P < 0.05) in the following variables (means +/- SEM, -Cu vs. +Cu): body weight (BW), 375 +/- 19 vs. 418 +/- 2.9 g; food intake, 16.2 +/- 0.7 vs. 18.5 +/- 0.4 g/d; hematocrit, 0.294 +/- 0.027 vs. 0.436 +/- 0.027; hemoglobin, 95.2 +/- 9 vs 134 +/- 10 g/L; liver Cu, 8.7 +/- 2.0 vs. 65.9 +/- 2.5 nmol/g; plasma Cu, 0.38 +/- 0.09 vs. 13.4 +/- 0.61 micromol/L; plasma ceruloplasmin activity, 1.75 +/- 1.0 vs. 67.9 +/- 8.4 IU; relative heart weight, 0.56 +/- 0.04 vs. 0.35 +/- 0.02% BW; relative liver weight, 4.06 +/- 0.23 vs. 3.37 +/- 0.06% BW; and liver CSAD activity, 18.8 +/- 1.37 vs. 13.5 +/- 1.11 nmol x min(-1) x mg protein(-1). The groups did not differ at wk 16 in: plasma taurine, 249 +/- 14 vs. 298 +/- 63 micromol/L; whole blood taurine, 386 +/- 32 vs. 390 +/- 25 micromol/L; urinary taurine excretion, 82.5 +/- 15 vs. 52.0 +/- 8.3 micromol/d; liver taurine, 2.6 +/- 0.7 vs. 2.8 +/- 0.4 micromol/g; liver total glutathione, 6.9 +/- 0.48 vs. 6.3 +/- 0.40 micromol/g; liver cyst(e)ine, 96 +/- 7.1 vs. 99 +/- 5.3 nmol/g and liver CDO activity, 2.19 +/- 0.33 vs. 2.74 +/- 0.21 nmol x min(-1) x mg protein(-1). These findings support the conclusion that Cu deficiency does not affect body taurine status.     

Influence of calorie source on the physiological response to parenteral nutrition in malnourished rabbits

The present study was designed to investigate whether calorie source influences sodium and water metabolism and sympathetic activity during parenteral nutrition (PN). 20 New Zealand rabbits were starved until a mean weight loss of 18% was achieved and then re-fed for 6 days with 2 formulae of PN with different glucose-fat proportions. In the Glucose group (n = 9), 70% of non-protein calories were given as glucose while in the Lipid group (n = 11), 70% of non-protein calories were administered as lipids. Rabbits with a high glucose intake showed significantly higher weight gain (151 +/- 87 vs. 52 +/- 7 g, P = 0.01), water cumulative balance (542 +/- 132 vs. 411 +/- 87 ml; P = 0.02) and urinary metanephrine excretion (0.42 +/- 0.12 vs. 0.30 +/- 0.1 mumol/d, P = .03). Only in this group, urinary metanephrines correlated positively with water and sodium balances (r2 = 0.6; P = 0.02 and r2 = 0.7; P = 0.009 respectively). The Glucose group showed 2 different responses and in a second experiment 10 additional rabbits were added to this group to allow a statistical analysis of the response pattern: half of the animals increased their extracellular water (ECW) compartment while the remaining animals did not. The former group had higher sodium balance (13.9 +/- 8 vs. 4.3 +/- 5; P = 0.004) and wet lung weight (8.9 +/- 0.9 vs. 7.9 +/- 0.8; P < 0.05) after re-feeding and, at the beginning of PN, their serum aldosterone concentration were also higher (221 +/- 11 vs. 130 +/- 47 pmol/l; P < 0.05). In conclusion, glucose based PN appears to increase sympathetic activity and induce spurious weight gain due to markedly positive wate and sodium balances. Plasma aldosterone concentration at the end of starvation period influences sodium retention and ECW expansion during high glucose re-feeding.     

Characteristics of the obesity syndrome in Zucker-Brown Norway (ZBN) hybrid rats

The existence of a restriction fragment length polymorphism (RFLP) closely linked to the fatty locus between the Zucker (Z) and Brown Norway (BN) rat strains allows evaluation of early effects of the fatty (fa) gene using offspring of back-crosses (N2) between F1 females and Zucker obese males. We examined several metabolic characteristics of N2 animals to determine if these hybrid animals exhibited similar characteristics of the obese syndrome to those of Zucker rats. Females from crosses of obese male Zucker (fa/fa) and lean female BN (+/+) rats were back-crossed to their sires, resulting in twelve N2 litters. At 9 weeks of age, liver, spleen, interscapular brown fat (IBAT), and gonadal, retroperitoneal (RP), and inguinal fat depots were removed and weighed. Samples of the RP depot were analyzed for cell size and number. Obese N2 rats were hyperphagic, with body weights in the range of those of obese Zucker rats. Obese N2 rats were also hyperinsulinemic [mean +/- SEM, microU/ml: females, 7.9 +/- 0.6 vs. 82.1 +/- 8.4 (lean vs. obese); males, 10.5 +/- 1.6 vs. 128.5 +/- 13.4 (lean vs. obese)] and mildly hyperglycemic [mean +/- SEM, mg/dl: females, 104.1 +/- 2.0 vs. 139.0 +/- 14.7 (lean vs. obese); males, 100.9 +/- 2.6 vs. 132.0 +/- 2.8 (lean vs. obese) p < or = 0.05]. White fat depots in obese rats were 3 to 7 times heavier than those in lean rats; adipocyte numbers in RP depots were 50% greater in obese than in lean rats; and cell size was more than 3 times larger. IBAT, liver, and spleen were also heavier in obese vs. lean rats, while tail lengths were shorter. Percent lean carcass mass and % carcass protein were about 30% greater in lean vs. obese rats, while % carcass fat in obese rats was 5 times greater than that of lean rats. Thus, phenotypic expression of the fa gene in ZBN hybrid animals, with approximately 25% of their genetic background coming from the BN strain, appears to be similar to that in Zucker rats. Given the similarity of phenotypic expression of the fa gene between the Zucker strain and ZBN hybrids, it is plausible to consider using ZBN hybrids for studies of early manifestations of fa gene action prior to onset of detectable obesity.     

三氯乙烯对豚鼠皮肤致敏作用与肝肾功能的损害

目的 探讨三氯乙烯(TCE)对豚鼠皮肤致敏作用及肝肾功能的损害.方法 采用豚鼠最大值试验(GPMT),将动物分成阴性对照组、阳性对照组和TCE实验组,每组6只豚鼠,分别皮内注射橄榄油、2,4-二硝基氯苯(DNCB)和TCE.实验结束后观察动物皮肤改变,应用自动生化分析仪检测致敏动物血清中丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)、白蛋白、球蛋白、乳酸脱氧酶(LDH)、肌苷、尿酸等指标.结果阳性对照组和TCE实验组动物出现明显皮肤红斑、水肿,阳性对照组动物致敏率为100%,TCE实验组动物致敏率为83.3%.阳性对照组动物血清中ALT、AST活力升高,TCE实验组动物血清中ALT、AST、LDH活力明显高于阴性对照组,差异有统计学意义(P＜0.05或P＜0.01).结论 TCE可诱导豚鼠产生明显的皮肤致敏作用,属强致敏物,并可引起实验动物肝功能指标的改变.     

1800 MHz电磁波暴露对大鼠海马N-甲基-D-天冬氨酸受体表达的影响

目的观察1800 MHz电磁波暴露对大鼠海马内NMDA受体亚单位NR2A、NR2B表达的影响.方法将4周龄雌性Wistar大鼠随机分为4组(0.5 和1.0 mW/cm2剂量组,各实验组分别设置1个对照组),每组12只.其中2个实验组大鼠每天12 h暴露于频率为1800 MHz、功率密度分别为0.5 mW/cm2和1.0 mW/cm2的电磁波环境中,共暴露21 d,同时,采用免疫组织化学和图像处理方法分析海马CA1、CA3、齿状回NR2A和NR2B的表达.结果(1)NR2A蛋白表达0.5 mW/cm2剂量组在CA3区表达的免疫反应灰度值为(8.5±1.5),与对照组的(11.1±1.8)比较,差异有统计学意义;在CA1区和齿状回表达的免疫反应灰度值与对照组比较,差异无统计学意义.1.0 mW/cm2剂量组在CA1和CA3区表达的免疫反应灰度值分别为(7.9±1.6)和(8.4±1.7),与对照组的(9.7±1.5)和(11.1±1.8)比较,差异有统计学意义;在齿状回表达的免疫反应灰度值差异无统计学意义.(2)NR2B蛋白表达0.5 mW/cm2剂量组在CA1和CA3区表达的免疫反应灰度值分别为(16.4±1.0)和(9.6±1.9),与对照组的(17.8±1.6)和(11.2±2.1)比较,差异有统计学意义;在齿状回表达的免疫反应灰度值差异无统计学意义.1.0 mW/cm2剂量组在CA1、CA3和齿状回表达的免疫反应灰度值分别为(13.1±2.4)、(9.3±1.4)和(7.3±0.1),与对照组的(17.8±1.6)、(11.2±2.1)和(8.5±1.0)比较,均差异有统计学意义.结论在本实验条件下,1800 MHz电磁波暴露可影响大鼠海马NMDA受体的表达.     

Isolated perfused liver model: the rat and guinea pig compared

OBJECTIVE: Although the rat is the most commonly used species for the study of hepatic metabolism, the physiology of the guinea pig is closer to human physiology. We compared the model of isolated perfused guinea pig liver with the classic model of isolated perfused rat liver, especially with respect to amino acid metabolism. METHODS: After validation of an anesthetic mixture of ketamine, diazepam, and xylazine for the guinea pig, isolated perfused livers were harvested for both species. Three groups of animals were compared for the study of liver metabolic fluxes: 6-wk-old male Sprague-Dawley rats (R; 230 +/- 10 g, n = 5), young male Hartley guinea pigs (YG; 223 +/- 8 g, n = 6) matched to rats by liver weight, and adult male Hartley guinea pigs (AG; 389 +/- 5 g, n = 6) matched to rats by age. Results (mean +/- standard error of the mean) were compared by analysis of variance and Newman-Keuls tests. RESULTS: Both models displayed a satisfactory hepatic viability, but differences were noted, with higher portal flows (R: 3.1 +/- 0.3 versus YG: 4.5 +/- 0.3 and AG: 4.2 +/- 0.3 mL. min(-1). g(-1); P < 0.05, YG and AG versus R) and bile flows (R: 0.34 +/- 0.01 versus YG: 2.38 +/- 0.22 versus AG: 3.17 +/- 0.28 microL. min(-1). g(-1); P < 0.05, YG and AG versus R, and YG versus AG) and higher amino acid fluxes (P < 0.05) leading to greater nitrogen uptake (P < 0.05) in guinea pigs. We performed a second set of experiments to evaluate the influence of anesthesia and portal flow on this last parameter. In these experiments, rats were anesthetized with ketamine, diazepam, and xylazine and guinea pig livers were perfused at rat blood flow. Apart from a 50% anesthesia-related mortality for rats, bile flow and metabolic parameters were only slightly modified. However, some amino acid fluxes were statistically different (aspartate, serine, and histidine; P < 0.05), as confirmed by a higher transfer constant. CONCLUSION: Our results indicate that the isolated perfused guinea pig liver is a suitable model for the study of hepatic metabolism.