富硒饲料对高脂血症大鼠红细胞和脑细胞风钙离子浓度的影响

为了研究富硒膳对高脂血症大鼠红细胞及脑细胞细胞内钙离子浓度的影响,用钙离子荧光指示剂Ｆｕｒａ－２／ＡＭ标记法分别测定大鼠红细胞及脑细胞内钙离子浓度。结果：补充硒的实验组大鼠脑细胞内钙离子浓度（猪油加硒组５９７．４９±５３２．８９ｎｍｏｌ／ｍｇｐｒ,玉米油中硒组２５７．８６±４３．３２ｎｍｏｌ／ｍｇｐｒ）水补充硒组（猪油组６和．５１±５７８．５９ｎｍｏｌ／ｍｇｐｒ,玉米油组４２８．１４±３０６．１０     

玉米油和猪油对大鼠血脂血糖代谢和脑脂褐质影响的比较研究

采用幼年ＳＤ雄性大鼠３０只，体重１５０±２０ｇ，随机分成三组，每组１０只：（１）基础饲料组：普通大鼠饲料；（２）猪油组：基础饲料中加入１０％猪油和１．５％胆固醇；（３）玉米油组：在基础饲料中加入１０％玉米油和１．５％胆固醇，饲养９周，比较玉米油和猪油对大鼠血脂血糖和脑脂褐质的不同影响。结果表明，玉米油组ＴＣ和ＬＤＬ－Ｃ水平较猪油组低，虽然两组均高于基础饲料组。玉米油组的ＨＤＬ－Ｃ比猪油升高不显著，但ＨＤＬ－Ｃ／ＴＣ（％）增加，同时ＬＤＬ－Ｃ／ＨＤＬ－Ｃ比值下降。基础饲料组，猪油组和玉米油组的大鼠平均血清ＴＧ分别为１.２８，１.２１和１.４５（ｍｍｏｌ／Ｌ），各组之间的差别不显著。高脂饲料组动物的空腹血糖（ＳＧ）较基础饲料组高，但差别无统计学意义。三组不同饲料大鼠的脑脂褐质（ＬＰＦ）含量测定结果显示:基础饲料组大鼠的ＬＰＦ平均值１２.９Ｕ／ｇ蛋白质，而玉米油组和猪油组均明显升高，分别为２８.３和２８.８Ｕ／ｇ蛋白质。在以血脂各项指标为自常量，大脑ＬＰＦ含量为因变量的相关分析中发现，ＬＰＦ与ＴＣ和ＬＤＬ－Ｃ呈正相关，相关系数分别为０.６９１和０.５４７，Ｐ＜０.０１．     

实验性高脂血症大鼠的血硒、维生素E、GSH－Px及脂质过氧化物的改变

采用幼年ＳＤ雄性大鼠３０只，随机分成３组，分别饲喂基础饲料，猪油饲料（１０％猪油和１．５％胆固醇）和玉米油饲料（１０％玉米油和１．５％胆固醇）。９周后，玉米油组和猪油组的大鼠形成高脂高胆固醇血症，第１０周处死动物，取血测定全血硒（Ｓｅ），谷胱甘肽过氧化物酶（６ＧＳＨ－Ｐｘ），血清维生素Ｅ（ＶＥ）和脂质过氧化物（ＬＰＯ）含量。结果由猪油和玉米油诱导的高血脂大鼠血Ｓｅ水平低于基础饲料组的大鼠，基础组、猪油组和玉米油组的血Ｓｅ值分别为０．０９６、０．０８１和０．０８０ｍｇ／Ｌ，而且随着饲养时间的延长，血Ｓｅ趋于下降，但各组间的差异无显著性意义。基础组和猪油组大鼠的ＧＳＨ－Ｐｘ活性分别为２０．０４和２１．０１ｍｍｏｌ／（ｍｉｎ．Ｌ），而玉米油组最低，仅为１１．０８ｍｍｏｌ／（ｍｉｎ．Ｌ），玉米油组与基础组和猪油组之间呈极显著差异（Ｐ＜０．０１）。血清ＬＰＯ含量在各组之间未观察到显著性差异（基础组１７．５８，猪油组１７．４４，玉米油组１７．７３μｍｏｌ／Ｌ）。但值得注意的是玉米油组的ＧＳＨ－Ｐｘ／ＬＰＯ比值为０．６３，明显低于基础组（１．１３）和猪油组（１．１９），说明玉米油组大鼠体内抗氧化能力减弱。猪油组血清ＶＥ浓?     

妊高钙患者红细胞膜Na^＋—K—ATP酶活性及钙结合量减低及其意义的探讨

妊高征病人红细胞膜Ｎａ＾－Ｋ－ＡＴＰ酶活性０．３１±０．１１μｍｏｌｐｉ／ｍｇ蛋白．小时＾－１，膜内面Ｃａ＾＋＋结合量５０．００±１７．５０ｎｍｏｌ／ｍｇ蛋白，正常孕妇红细胞膜以上两项指标分别为０．４５±０．１３μｍｏｌｐｉ／ｍｇ蛋白．小时＾－１和６９．６±１９．１２ｎｍｏｌ／ｍｇ蛋白。     

妊高征患者红细胞膜Na~+-K~+-ATP酶活性及钙结合量减低及其意义的探讨

妊高征病人红细胞膜Ｎａ＋－Ｋ＋－ＡＴＰ酶活性０．３１±０．１１μｍｏｌｐｉ／ｍｇ蛋白·小时－１，膜内面Ｃａ结合量５０．００±１７．５０ｎｍｏｌ／ｍｇ蛋白，正常孕妇红细胞膜以上两项指标分别为０．４５±０．１３μｍｏｌｐｉ／ｍｇ蛋白·小时－１和６９．６±１９．１２ｎｍｏｌ／ｍｇ蛋白。将两组同一指标进行统计学分析，Ｐ均小于０．０１，具有显著性差异。提示妊高征时细胞膜钠泵功能和膜内面结合Ｃａ的能力减低，这些变化可能与妊高征高血压的发生和发展有一定关系。     

砷中毒对小鼠脑细胞内钙离子浓度影响的研究

目的:探讨砷中毒导致脑细胞损伤的机制。方法:采用尾静脉注射亚砷酸钠建立中毒动物模型,以Fluo-3/AM为细胞内游离钙离子的荧光指示剂,用激光扫描共聚焦显微镜测定脑细胞内[Ca2+]i的含量变化,同时采用原子吸收分光光度计测定脑组织中砷(As)、用生化试剂盒测定超氧化物歧化酶(SOD)、丙二醛(MDA)的活性水平。结果:实验组小鼠脑细胞内的平均荧光强度明显高于对照组,实验组为116.10±33.75,对照组为42.78±22.66(P<0.001);实验组小鼠脑组织中As含量、MDA水平明显高于对照组,而SOD水平则低于对照组,两组差异有显著性意义(P<0.05)。结论:砷可增加小鼠脑细胞内的游离钙离子浓度,提示脑细胞内钙超载可能是其致脑细胞损伤的分子机制之一。     

CGRP对缺氧缺血新生鼠脑细胞内游离Ca2+的影响

目的探讨降钙素基因相关肽(CGRP)对缺氧缺血新生鼠脑细胞内游离Ca2+的影响及对脑损伤的保护作用.方法 7日龄SD大鼠制成HIE模型.⑴药物治疗组于模型后即给CGRP 3μg*kg-1*d-1,腹腔内注射,共3d;⑵生理盐水组每天给予同剂量生理盐水腹腔内注射;⑶正常对照组(假手术组).各组于3d后断头取脑,采用钙荧光指标剂Fura-2AM法测定脑细胞胞浆游离钙浓度[(Ca2+)].结果生理盐水组脑细胞内钙含量最高,(129.47±17.21nmol/L)与正常对照组(93.72±24.16nmol/L)比较有显著差异P＜0.01,而药物治疗组(103.35±12.46nmol/L)与正常对照组比较无显著差异.结论 CGRP能阻止新生鼠缺氧缺血脑损伤后细胞钙内流,降低细胞膜对Ca2+通透性可能是CGRP对脑缺氧缺血保护作用的重要机制.     

大鼠补硒后血谷胱甘肽过氧化酶，维生素E和脑脂褐质的变化

采用猪油（Ｌ）或玉米油（Ｍ）加胆固醇饲料诱导大鼠高脂血症模型以含硒量约为３．５ｍｇ／ｋｇ的富硒饲料Ｌａｒｄ－Ｓｅ（Ｌ一Ｓｅ），Ｍａｉｚｅｏｉｌ－Ｓｅ作为干预因素，观察实验性高脂血症大鼠补硒后血液ＧＳＨ－Ｐｘ，ＶＥ和大脑脂褐质（ＬＰＦ）的变化。结果表明，Ｌ－Ｓｅ组的ＧＳＨ－Ｐｘ活性比Ｌ组升高４２．８６％；玉米油是否加硒的两组（Ｍ和Ｍ－Ｓｅ）动物血清ＶＥ浓度均高于Ｌ，Ｍ－Ｓｅ组比Ｍ组升高２４．７７％。但富硒的Ｌ－Ｓｅ组ＶＥ水平比Ｌ组升高近７３％。此外，补硒动物（Ｌ－Ｓｅ和Ｍ－Ｓｅ）的大脑ＬＰＦ明显低于非补硒组。相关分析的结果显示，血Ｓｅ，肝Ｓｅ含量与ＧＳＨ－Ｐｘ呈明显正相关，血硒与血清ＶＥ呈正相关，肝硒与大脑ＬＰＦ呈明显负相关。上述结果提示，富硒饲料对增强高血脂大鼠体内抗氧化能力，减少脂质过氧化作用有效。     

核黄素缺乏大鼠红细胞维生素E水平的变化及脂质过氧化关系的研究

对两组大鼠分别喂饲核黄素缺乏（ＲＤ）膳和核黄素添加（Ｒ８，２２ｍｇ／ｋｇ饲料）膳８周后，测定了两组大鼠的红细胞维生素Ｅ（ＲＢＬＶｅ）、红细胞超氧化物歧化酶（ＳＯＤ）和红细胞丙二醛（ＭＤＡ）的水平。结果发现：ＲＤ组ＲＢＣＶｅ水平（４．７１７３±０．７７１０ｍｇ／ｇ蛋白质）显著低于ＲＳ组（５。３８６８±１．１５３７ｍｇ／ｇ蛋白质，Ｐ＜０．０５）。而ＲＤ组的ＲＢＣＳＯＤ（７７４５．２±６１０．１ｕ／ｇ蛋白质）和ＭＤＡ（０．６８６８±０．１３７２μｇ／ｇ蛋白质）则分别显著低于和高于ＲＳ组（８２６８．５±３０１．０ｎｕ／ｇ蛋白质，０．５５４８±０．０９８０，Ｐ＜０．０５）。研究提示，核黄素缺乏引起细胞膜脂质过氧化加重可能ＲＢＣＶｅ消耗增加。     

降钙素基因相关肽对新生鼠HIE脑组织内皮素及脑细胞内钙的影响

【目的】研究降钙素基因相关肽(calciumgene-relatedpeptide,CGRP)对新生鼠缺氧缺血性脑损伤(hypoxic-ischemicencephalopathy,HIE)脑组织内皮素(endothelin,ET)及脑细胞内游离钙离子(intracellularfreecal-cium,IFCa)的影响。【方法】将45只7日龄SD(Spraque-Dawley)大鼠平均分成3组:①CGRP治疗组于HIE模型后即给予CGRP3μg/(kg.d)加生理盐水(NS)2ml稀释后,腹腔内注射,共3d;②NS组于HIE模型后即给予NS2ml/d,腹腔内注射,共3d;③正常对照组(假手术组)。各组于3d后断头取脑,采用放射免疫法检测脑组织ET含量,应用钙荧光指示剂Fura-ZAM法测定IFCa。【结果】NS组ET及IFCa含量[(93.41±12.73)ng/L及(129.47±17.21)nmol/L]明显高于正常对照组[(57.58±6.31)ng/L及(93.72±24.16)nmol/L]和CGRP治疗组[(61.68±6.83)ng/L及(103.35±12.46)nmol/L](P<0.01),而CGRP治疗组ET及IFCa含量与正常对照组比较差异无显著性(P>0.05)。【结论】CGRP能拮抗ET收缩血管的作用,改善脑循环,抑制ET的合成及释放,同时能阻止脑细胞钙内流,保护缺氧缺血性脑损伤。     

花生油、茶油、牛油对大鼠脂质过氧化、膜磷脂脂肪酸组成及膜流动性的影响

用含11％花生油、茶油、牛油的饲料分别饲养SD大鼠，观察其血清和心、肝、脑丙二醛（MDA）、血清和肝超氧化物歧化酶（SOD）水平、生物膜磷脂脂肪酸组成及膜流动性的改变。结果发现：花生油组心线粒体及牛油组RBC膜磷脂脂肪酸含量与摄入脂肪酸呈正相关（r分别为0.6275和0.6967，P＜0.01）。喂饲花生油引起生物膜磷脂多不饱和脂肪酸含量增加，膜流动性增高，血清和肝SOD水平较低（分别为3.76±1.61mg／L、616±163μg／g），血清MDA较高（8.70±1.71μmol／L），提示脂质过氧化程度较高。喂饲茶油引起膜磷脂单不饱和脂肪酸含量增加，膜流动性和血清SOD（5.66±2.00mg／L）较高，血清及脑MDA较低（5.92±1.15μmol／L，2.45±0.44μmol／g），提示脂质过氧化程度较低。喂饲牛油引起膜磷脂饱和脂肪酸含量增加，膜流动性较低，血清及肝SOD较高（5.79±0.56mg／L，886±99μg／g），血清MDA较低（7.04±1.66μmol／L），脑MDA较高（3.96±1.68μmol／g），脂质过氧化程度介于花生油组与茶油组之间。     

Folic acid fortification increases red blood cell folate concentrations in the Framingham study.

In 1996 the Food and Drug Administration (FDA) issued a regulation to take effect in January 1998 that all enriched cereal grain products include 140 microg of folic acid/100 g. The present cross-sectional study was undertaken to assess the effect of this fortification on RBC folate concentrations in the Framingham Offspring Cohort. Among those who did not take B-vitamin supplements, we compared RBC folate in 561 individuals who were examined before implementation of the FDA mandatory folic acid fortification (not exposed) vs. 354 individuals who were examined after implementation of fortification (exposed). We calculated the prevalence of deficient (<160 microg/L, 362.6 nmol/L) and acceptable (>200 microg/L, 453.2 nmol/L) RBC folate concentrations in both groups. Those exposed to folic acid fortification had a mean RBC folate of 450.0 microg/L (1019.7 nmol/L), a value 38% higher than the mean RBC folate of 325.3 microg/L (737.1 nmol/L) in those who were not exposed to fortification (P < 0.001). The prevalence of individuals with deficient RBC folate was 4.9% in the group not exposed to fortification compared with 1.9% in the group exposed to fortification (P < 0.02), and the prevalence of individuals with acceptable RBC folate was 87.0% in the group not exposed to fortification compared with 96.1% in the group exposed to fortification (P < 0.001). Similar results were seen in individuals who used supplements containing B-vitamins. The results of this study showed that in this cohort, the introduction of folic acid fortification significantly improved folate nutritional status measured as RBC folate.     

饮水染镉对大鼠睾丸及血液抗氧化功能影响

目的 探讨饮水染镉对雄性大鼠睾丸及血液抗氧化功能影响.方法 将30只雄性SD大鼠(性成熟)随机分成5组,分别为对照组,25、50、100、200 mg/L CdCl₂组,经饮水染镉,连续56 d;检测大鼠睾丸、血液中谷胱甘肽过氧化物酶(GSH-Px)活性、超氧化物歧化酶(SOD)活性以及丙二醛(MDA)含量.结果 与对照组比较,200 mg/L染镉组大鼠睾丸中GSH-Px活性[(7.94±2.25)μmol/(min·gprot)]降低(P< 0.05),MDA含量[(5.84±0.61)nmol/mgprot]明显升高(P< 0.01);与对照组比较,200 mg/L染镉组大鼠全血GSH-Px活性[(32.99±4.45)μmol/(min·gprot)]、红细胞SOD活性[(8 574.79±887.65)NU/gHb]、血浆SOD活性[(9.94±1.38)NU/mgprot]明显下降(P< 0.05),血浆MDA含量[(0.26±0.03)nmol/mgprot]明显上升(P< 0.05).结论 饮水染镉可引起雄性大鼠睾丸及血液抗氧化功能损伤.     

核黄素缺乏大鼠红细胞膜流动性与脂质过氧化关系的研究

对两组大鼠分别喂饲核黄素缺乏(RD)膳和核黄素添加(RS,22mg/kg饲料)膳。7周后,测定了大鼠红细胞(RBC)膜荧光偏振度(P)和平均微粘度(?),RBC膜丙二醛(MDA)及RBC超氧化物歧化酶(SOD)。结果表明:RD组大鼠RBC膜P值和(?)值(分别为0.2976±0.0198和3.9483±0.3680)均高于RS组(0.2760±0.0207和2.8753±0.4634),差别分别呈显著和极显著统计学意义(P<0.05,P<0.01)。而RD组的RBC膜MDA(0.6868±0.1732nmol/mg蛋白质)和RBC SOD(7.7452±0.0610nU/mg蛋白质)则分别高于和低于RS组(0.5548±0.0980nmol/mg蛋白质和8.2685±0.3010nU/mg蛋白质),差别均有显著统计学意义(P<0.05)。研究表明:核黄素缺乏可引起大鼠RBC膜流动性下降,并与RBC膜脂质过氧化加重、清除自由基能力下降有关。     

溴氰菊酯对大鼠神经细胞胞内游离钙浓度及凋亡的影响

目的　观察溴氰菊酯 (DM )对神经细胞游离钙浓度 ([Ca2 + ]i)及凋亡的影响。方法　Wistar大鼠随机分为对照组与 3个染毒组 ,染毒组腹腔注射 1 2 .5mg/kg的DM ;以Fura 2 /AM为荧光指示剂 ,RF 530 1PC荧光分光光度计测定染毒后 5、2 4、48h后大鼠神经细胞 [Ca2 + ]i浓度的变化 ;FACS42 0型流式细胞仪测定细胞凋亡率。结果　PM染毒 5、2 4、48h组大鼠海马及皮层细胞 [Ca2 + ]i分别为 :5h组海马 :(389.94± 43 .64)nmol/L、皮层 :(449.33± 2 3 .2 3)nmol/L ;2 4h组海马 :(340 .47±32 .36)nmol/L、皮层 :(31 1 .62± 2 5 .48)nmol/L ;48h组海马 (2 87.1 3± 2 4 .2 9)nmol/L、皮层 :(346 .55±36 .87)nmol/L ,均高于对照组 [海马 :(2 0 3 .2 4± 1 8.53)nmol/L、皮层 :(2 2 6 .85± 1 4 .81 )nmol/L] ,差异有显著性 (P <0 .0 1 )。染毒 48h组大鼠此二项指标值较 5h组明显下降 ,差异有显著性 (P <0 .0 5)。染毒 2 4、48h组大鼠神经细胞凋亡率 [海马 :(8.45± 1 .0 2 ) %、(9.44± 1 .1 4 ) % ,皮层 :(7.90± 0 .49) %、(8.0 1± 0 .87) % ]均明显高于对照组 [海马 :(2 .97± 0 .36) %、皮层 :(3 .50± 0 .48) % ] ,差异有显著性 (P<0 .0 1 ) ,且有时间 反应关系 (r=0 .940、0 .893)。结论　DM可影响大鼠神     

Carotenoid-biofortified maize maintains adequate vitamin a status in Mongolian gerbils

Efforts to biofortify maize with provitamin A carotenoids have been successful, but the impact on vitamin A (VA) status has not been determined. We conducted two studies that investigated the bioefficacy of provitamin A carotenoids from maize and compared maize percentage and carotenoid concentrations on VA status in VA-depleted Mongolian gerbils (Meriones unguiculatus). Gerbils (n = 40/study) were fed a white maize diet 4 wk prior to treatment. In study 1, treatments (n = 10/group) included oil control, 60% high-beta-carotene maize, and beta-carotene or VA supplements (matched to high-beta-carotene maize). In study 2, gerbils were fed 30 or 60% orange or yellow maize diets. Gerbils were killed after 4 wk. In study 1, liver VA concentrations, compared with the high-beta-carotene maize group (0.25 +/- 0.15 micromol/g), were higher in the VA group (0.56 +/- 0.15 micromol/g, P < 0.05), lower in the control (0.10 +/- 0.04 micromol/g, P < 0.05), and did not differ in the beta-carotene group (0.25 +/- 0.08 micromol/g). Bioconversion was approximately 3 microg beta-carotene to 1 mug retinol (1.5 mol beta-carotene to 1 mol retinol). The liver beta-carotene content was greater in the high-beta-carotene maize group (26.4 +/- 6.0 nmol) than in the beta-carotene supplement group (14.1 +/- 6.0 nmol; P < 0.05). In study 2, the gerbils' VA status improved with increasing dietary beta-carotene. Liver VA in gerbils fed orange maize was greater than in those fed yellow maize, regardless of maize percentage (P < 0.05). Biofortified maize adequately maintained VA status in Mongolian gerbils and was as efficacious as beta-carotene supplementation. In populations consuming maize as a staple food, using orange instead of white maize could dramatically affect VA status.     

Rat small intestinal morphology and tissue regulatory peptides: effects of high dietary fat.

Sprague-Dawley rats (3 weeks old) were fed on isoenergetic diets in which 40% of the total energy was provided as fat either in the form of butter (high saturated fat), olive oil (high monounsaturated fat) or maize oil (high polyunsaturated fat), with one group on low-fat (10% of total energy) standard diet as a control. Animals were killed after 8.4 (se 0.8) weeks by cardiac puncture. Similar pieces of jejunum and ileum were prepared for morphometric studies. Extracts of tissue from the proximal and distal segments of the whole small intestine from four animals per group were assayed using established techniques for enteroglucagon, motilin, neurotensin, somatostatin, substance P and vasoactive intestinal peptide (VIP). We found that maize oil and olive oil increased villus height: crypt depth ratio in both jejunum and ileum. Maize oil increased tissue concentrations of somatostatin (P less than 0.05) and substance P (P less than 0.005) in the proximal segment. Both maize oil and olive oil increased tissue concentrations of neurotensin and substance P (P less than 0.005) in the distal segments. These observations may explain the improvement of intestinal absorption of fluid following supplementation with polyunsaturated fat.     

beta-Cryptoxanthin from supplements or carotenoid-enhanced maize maintains liver vitamin A in Mongolian gerbils ( Meriones unguiculatus) better than or equal to beta-carotene supplements

Maize with enhanced provitamin A carotenoids (biofortified), accomplished through conventional plant breeding, maintains vitamin A (VA) status in Mongolian gerbils (Meriones unguiculatus). Two studies in gerbils compared the VA value of beta-cryptoxanthin with beta-carotene. Study 1 (n 47)examined oil supplements and study 2 (n 46) used maize with enhanced beta-cryptoxanthin and beta-carotene. After 4 weeks' depletion, seven or six gerbils were killed; remaining gerbils were placed into weight-matched groups of 10. In study 1, daily supplements were cottonseed oil, and 35, 35 or 17.5 nmol VA (retinyl acetate), beta-cryptoxanthin or beta-carotene, respectively, for 3 weeks. In study 2, one group of gerbils was fed a 50% biofortified maize diet which contained 2.9 nmol beta-cryptoxanthin and 3.2 nmol beta-carotene/g feed. Other groups were given equivalent b-carotene or VA supplements based on prior-day intake from the biofortified maize or oil only for 4 weeks. In study 1, liver retinol was higher in the VA (0.74 (SD 0.11) micromol) and beta-cryptoxanthin (0.5 (SD 0.10) micromol) groups than in the beta-carotene (0.49 (SD 0.13) micromol) and control (0.41 (SD 0.16) micromol)groups (P<0.05). In study 2, the VA (1.17 (SD 0.19) micromol) and maize (0.71 (SD 0.18) micromol) groups had higher liver retinol than the control (0.42 (SD 0.16) micromol) group (P<0.05), whereas the beta-carotene (0.57 (SD 0.21) micromol) group did not. Bioconversion factors (i.e. 2.74 microg beta-cryptoxanthin and 2.4 microg beta-carotene equivalents in maize to 1 microg retinol) were lower than the Institute of Medicine values.