镉对大鼠胰脏的毒作用

目的探讨镉对内分泌和外分泌功能的影响。方法将96只SD大鼠分为4组,分别为对照组和50、100、200mg/LCdCl2染毒组,饮水染毒30、60、90d。测定不同染毒时间大鼠血糖、尿糖、血胰岛素、淀粉酶的改变及血液中金属含量的改变;测定尿N-乙酰-β-D-氨基葡萄糖苷酶(NAG);并测定了胰脏组织中金属的含量以及胰脏金属硫蛋白基因、胰岛素基因和淀粉酶基因的表达情况。结果染毒组大鼠血糖水平在染毒90d的中、高剂量组有明显增加,差异有统计学意义(P<0.05),中剂量组血糖平均值为5.83mmol/L,高剂量组为6.46mmol/L;发现尿糖水平的增高先于尿NAG的增高。各剂量组大鼠血液和胰脏中镉的含量明显增加。在染毒90d中、高剂量组血锌含量降低。在染毒30d的中、高剂量组血液中胰岛素水平明显降低,而血淀粉酶改变不明显。在染毒90d的中、高剂量组胰脏组织中锌的含量明显增加。胰脏中金属硫蛋白基因表达均有不同程度的增加;胰岛素基因的表达除染毒60d中剂量组明显降低外,其他各组差异均无统计学意义(P>0.05)。而胰淀粉酶的基因表达在染毒60d和90d的中、高剂量组均明显增高。结论镉可以在胰脏组织蓄积,引起组织中必需元素锌水平的改变,导致基因和蛋白表达的改变,进一步引起胰脏内、外分泌功能的改变。     

镉对雌性大鼠血清FSH、LH水平的影响

目的 研究镉对雌性大鼠血清FSH(促卵泡激素)、LH(黄体生成激素)水平的影响。方法 以不同剂量镉(分别为0、0.25(或0.5)mg/kg、1.0mg/kg)对雌性大鼠进行亚急性、亚慢性注射染毒。一批大鼠染毒7、14d后测定血清中的LH、FSH的变化;另一批大鼠染毒30d后测定血清中LH、FSH含量。结果 染毒7、14d天大鼠血清FSH、LH含量高、低剂量组与对照组比较差异均无显著性(P>0.05);染毒30d,各剂量组大鼠血清中LH、FSH仍未见显著差异(P>0.05)。结论 在本实验条件下,染镉雌性大鼠血清FSH、LH水平未见明显变化。结论镉亚急性及亚慢性染毒,尚未造成雌性大鼠垂体功能损伤,抑或存在损伤仍能通过垂体的代偿功能而维持FSH、LH在正常水平范围。     

亚慢性镉染毒致大鼠心脏损伤探讨

目的 观察氯化镉(CdC12)亚慢性染毒对大鼠心脏组织的损伤作用.方法 96只SD大鼠随机分成镉高剂量组、中剂量组、低剂量组和生理氯化钠对照组,每组24只,雌雄各半,给予CdCl2腹腔注射,每天1次,每周5d,连续14周.测定大鼠心脏组织中镉水平和脏器系数的变化,现察其心肌组织病理学改变.结果 镉染毒雄性大鼠心脏镉水平在高剂量组、中剂量组和低剂量组分别为5.764、2.450和0.789 μg/g,分别是对照组的 115.28、49.00和15.78倍;而雌性大鼠心脏镉水平在上述3个剂量组分别为5.147、2.180和1.219μg/g,分别是对照组的102.94、43.60和24.38倍,差异均有统计学意义(P<0.01).两性大鼠心脏脏器系数均随着镉染毒水平的增加而有不同程度的升高,有明显的剂量依赖关系(P<0.01)0所有染毒大鼠心脏组织出现不同程度的形态结构改变,主要有心肌纤维排列疏松,间陈增宽,细胞核固缩、碎裂、崩解,甚至心肌坏死,这些病理学改变随着镉染毒水平的增加而更加明显.结论　亚慢性镉染毒可引起大鼠心脏组织内镉蓄积,导致染毒大鼠心肌坏死等明显的组织病理学改变.     

镉对大鼠雌性性腺毒性研究

目的　镉的雌性性腺生殖毒性研究颇少见。本文通过亚慢性镉染毒,观察了镉对大鼠的雌性性腺毒性。方法　随机将动物分四组,染镉剂量分别为１ 、０－５ 、０－２５ 和０ ｍｇ／ｋｇ 体重。腹腔注射染毒,每日一次,每周５ 天,连续６ 周。结果　镉染毒各剂量组大鼠卵巢镉含量均显著高于对照组;高、中剂量染毒组大鼠动情周期均比对照组显著延长;高、中剂量染毒组大鼠闭锁卵泡构成比显著高于对照组。结论　卵巢同肾脏一样,也是镉的重要的靶器官之一。镉的雌性性腺生殖毒性可表现为动情周期的明显延长,卵巢细胞生长发育过程的明显障碍     

大鼠体内镉负荷与尿金属硫蛋白关系的实验研究

[目的]分析大鼠尿金属硫蛋白(UMT)与体内镉负荷的关系,探讨UMT作为镉接触性生物标志物的可行性。[方法]24只SD大鼠分为4组,分别皮下注射给予0、0.5、1.0、2.0mgCd/kg体重CdCl27d。原子吸收分光光度法(AAS)测定肝脏、肾脏、胰脏、尿液、血液中镉的含量;比色法测定尿N-乙酰-β-D-氨基葡萄糖苷酶(UNAG)水平;酶联免疫吸附法(ELISA)检测UMT的含量。[结果]镉染毒大鼠血镉、尿镉、肝镉、肾镉、胰镉含量随染镉剂量的增加而明显增加,与对照组相比差异有统计学意义(P<0.05);各染镉组大鼠UNAG水平未见明显改变(P>0.05);UMT含量随着染镉剂量的增加而明显增加(P<0.05),并且与肝镉、肾镉、胰镉、血镉、尿镉含量呈明显正相关,相关系数分别为0.703、0.815、0.691、0.654、0.641(P<0.01)。[结论]UMT与体内镉负荷指标间存在较好的一致性,能反映机体镉负荷水平,可作为镉接触生物标志物。     

丙烯腈对雄性大鼠脂质过氧化作用研究

目的 研究丙燃腈对机体的脂质过氧化作用。方法 给雄性大鼠皮下注射丙烯腈,测定染毒３８天和７７天血及睾丸组织脂质过氧化指标;并对睾丸、附睾进行病理学检查。结果 染毒３８天中、高剂量组大鼠血中谷胱甘肽（ＧＳＨ）含量显著升高,各剂量组大鼠睾丸中谷胱甘肽过氧化物酶（ＧＳＨ－Ｐｘ）显著下降且与染毒剂量呈高度负相关（ｒ＝－０．４６４,Ｐ〈０．０１）;染毒７７天高剂量组大鼠务中ＧＳＨ－Ｐｘ显著下降,各剂量组血中     

经口镉染毒大鼠前列腺中金属硫蛋白基因表达水平的变化

目的 观察经口镉染毒对大鼠前列腺组织中锌、镉含量以及金属硫蛋白（MT）基因表达水平的影响。方法 48只大鼠随机分成8组，每组6只，其中设对照组和50、100、200mg/kg镉染毒组各2组。大鼠通过饮水给予氯化镉，并分别在染毒1个和6个月后分批（每批4组）处死大鼠。大鼠前列腺组织中锌、镉含量的测定采用原子吸收光谱法，而金属硫蛋白基因（MT－I和MT-Ⅱ）表达水平的测定采用RT－PCR的方法。结果 在镉染毒的每1个月和第6个月，随着镉染毒剂量的增加，锌在大鼠前列腺腹叶中的含量呈逐渐降低的趋势。其中在镉染毒1个月和6个月后，200mg/kg镉染毒组大鼠前列腺腹叶中锌的含量分别为9．5、8．5μg/g湿重，明显低于对照组的17．0、18．9μg/g湿重，差异有显著性（P＜0．05）。与锌相反，各染毒组大鼠前列腺腹叶和背侧叶中镉的含量均明显高于对照组，尤以背侧叶增高的幅度更明显。MT－I和MT－Ⅱ在前列腺腹叶的表达水平随着镉染毒剂量的增大而呈逐渐降低趋势；在染毒第1个月和第6个月，200mg/kg镉染毒组的MT－I基因相对表达丰度为0．410和0．339，MT－Ⅱ基因相对表达丰度为0．100和0．112，均明显低于对照组MT－I（0．760，0．830）和MT－Ⅱ（0．429，0．439）相对表达丰度，差异有显著性（P＜0．01）。显著 经口镉染毒能影响大鼠前列腺组织中锌、镉的含量和MT基因表达的水平。     

健脾泻浊方对亚急性镉染毒大鼠肾毒性影响的实验研究

目的 探讨中药健脾泻浊方对亚急性镉染毒大鼠肾毒性的影响.方法 无特定病原体级SD雄性大鼠37只,随机分为空白对照组(7只)和模型组(30只).空白对照组予腹腔注射生理氯化钠溶液,模型组大鼠以腹腔注射氯化镉混合液的方法制备亚急性镉中毒模型.于造模成功后,模型组随后被分为氯化镉染毒对照组(10只)、染毒后低剂量治疗组(10只)、高剂量治疗组(10只)共3组.对3组大鼠分别灌胃给予生理氯化钠溶液(10 ml·kg-1·d-1)和低剂量(4.23 g·kg-1·d-1)、高剂量(8.46 g·kg-1·d-1)的中药健牌泻浊方.各组于实验终末抽取血液并留取肝、肾组织测定镉水平,并测定血液中尿素氮(BUN)和肌酐(Cr)水平.结果 氯化镉粢毒对照组的血、肝、肾镉水平均高于空白对照组(P<0.01),血BUN也高于空白对照组(P<0.05).采用中药健脾泻浊方治疗后,高剂量治疗组和低剂量治疗组的血镉、肝镉、肾镉与氯化镉染毒对照组比较差异均无统计学意义(P>0.05).氯化镉染毒对照组、染毒后低剂量治疗组和高剂量治疗组各组组内的肝镉、肾镉分别与血镉比较差异均有统计学意义(P<0.01),肝镉、肾镉均较血镉高;氯化镉染毒对照组的肝镉、肾镉比较差异无统计学意义(P>0.05),但染毒后低剂量治疗组和高剂量治疗组组内的肝镉、肾镉比较差异均有统计学意义(P<0.01),肝镉较肾镉高.结论 健脾泻浊方对亚急性镉染毒大鼠没有增加肾的毒性作用,其对体内镉的驱排作用也不明显.     

亚慢性铅镉联合染毒对SD大鼠血液生理生化指标的影响

目的研究亚慢性铅镉联合染毒对SD大鼠血液生理生化的影响。方法将80只健康SD大鼠,随机分成3个试验组和1个对照组,每日对各试验组大鼠经口给予29.96、89.88和269.65 mg/kg铅镉混合溶液,对照组自由饮水,持续灌胃90 d。每30 d采集一次血液,测定血液生理生化指标。结果与对照组相比,各试验组大鼠血液白细胞总数、红细胞总数和血红蛋白含量总体呈现先上升后下降的显著变化;谷草转氨酶活性、谷丙转氨酶活性和尿素含量持续显著上升;血糖和总胆固醇含量最高剂量组显著下降,甘油三酯含量表现为最低剂量组显著上升;总蛋白、白蛋白、球蛋白、肌酐含量无显著变化。同时,各剂量组大鼠肝细胞和肾小管上皮细胞出现不同程度的颗粒变性、水泡变性和细胞坏死。结论亚慢性铅镉联合暴露对大鼠的血液生理生化指标有显著影响,长期低剂量铅镉联合染毒后可引起动物机体不同程度的肝功能和肾功能损伤。     

镉染毒去卵巢大鼠模型的骨量丢失

目的 研究镉对去卵巢大鼠骨丢失的影响。方法 将6月龄SD雄性大鼠行人工去卵巢技术，分5组，每组9只；假手术组；对照组（去卵巢，0mg/L Cd）；低剂量组（去卵巢 50mg/L Cd）；中剂量组（去卵巢 100mg/L Cd）；高剂量组（去卵巢 200mg/L Cd）。均经饮用水镉染毒。24周后处死动物，测定股骨颈骨密度，雌二醇、血、尿镉、尿β2-微球蛋白、骨镉、骨钙、粪钙、尿钙。结果 大鼠去卵巢后，体内雌二醇及骨密度明显下降，镉染毒可使去卵巢大鼠股骨颈的骨密度降低更明显，且呈剂量-反应关系。镉染毒大鼠发生肾损伤，表现为尿β2-微球蛋白含量升高，镉染毒后，去卵巢大鼠粪钙及尿钙排泄明显增加，且呈剂量-反应关系，高剂量组去除卵巢大鼠的骨钙含量也显著性下降。结论 镉可加剧去卵巢大鼠的骨量丢失，肠钙及尿钙的排泄量增加，骨钙含量降低，骨密度下降。     

Effect of butanol fraction from Cassia tora L. seeds on glycemic control and insulin secretion in diabetic rats

Cassia tora L. seeds have previously been reported to reduce blood glucose level in human and animals with diabetes. In the present study, the effects of Cassia tora L. seed butanol fraction (CATO) were studied on postprandial glucose control and insulin secretion from the pancreas of the normal and diabetic rats. Diabetes was induced by an i.p. injection of Streptozotocin (55 mg/kg BW) into the male Sprague-Dawley rats. The postprandial glucose control was monitored during a 240 min-period using a maltose loading test. In normal rats, rats fed CATO (20 mg/100 g BW/d) showed lower postprandial glucose levels in all the levels from 30 min up to 180 min than those in the control rats without CATO (p<0.05). In diabetic rats, those levels in the CATO group seemed to be lower during the 30~180 min, but only glucose level at 30 min showed significant difference compared to that in the control group. Moreover, CATO delayed the peak time of the glucose rise in both normal and diabetic rats in the glucose curves. On the other hand, when CATO was administered orally to the diabetic rats for 5 days, 12 hr fasting serum glucose level was decreased in the diabetic rats (p<0.05). Degree of a decrease in 12 hr fasting serum insulin levels was significantly less in the diabetic CATO rats as compared to diabetic control rats. On the last day of feeding, β cells of the pancreas were stimulated by 200 mg/dL glucose through a 40 min-pancreas perfusion. Amounts of the insulin secreted from the pancreas during the first phase (11~20 min) and the second phase (21~40 min) in the CATO fed diabetic rats were significantly greater than those in the diabetic control group (p<0.05). These findings indicated that constituents of Cassia tora L. seeds have beneficial effect on postprandial blood glucose control which may be partially mediated by stimulated insulin secretion from the pancreas of the diabetic rats.     

The distribution of tracer doses of cadmium in the normal rat

The distribution and excretion of a single tracer dose of cadmium-109 given intravenously to rats were studied in a 60-day time course experiment. The organs that accumulated the most cadmium were the liver, kidneys, and pancreas. Initial high plasma levels decreased rapidly, and most of the cadmium that remained in the blood after 24 hr was found in the red cells. In most organs and tissues a level was reached within 24 hr at which the cadmium concentration remained relatively stable. Kidney was a marked exception because the amount of cadmium found in that organ increased progressively. Excretion of cadmium was found to be predominantlyvia the feces. Twenty-five to 28% of the dose was excreted by that route in 60 days, the most rapid phase occurring during the first three days. Less than 0.15% of the dose was excretedvia the urine.     

经口摄入高硒高镉对大鼠血液和组织中硒含量影响的研究

选用4周龄SD大鼠,经口染毒高硒(5.68mm/kg)、富硒(0.73mm/kg)和(或)高镉(33.3mg/kg)12周,并分别在实验的第3、6、9、12周末各处死一批大鼠,研究经日摄入高硒高镉对大鼠血液和心、肝、肾、肺、脑、脾等组织中硒含量的影响。结果表明:与单独的高硒组相比,同时摄入高硒高镉组大鼠血液和组织中硒含量显著降低,肝、肾尤为明显,降低了硒在大鼠体内的蓄积。提示在高硒高镉地区,镉对地方性硒中毒的发生、发展可能产生有益影响。     

四种锌化合物的生物利用率的比较

目的：以边缘性锌缺乏的大鼠和幼鼠为模型，观察硫酸锌、葡萄糖酸锌、乳酸锌和甘氨酸锌四种锌化合物在０～７２０分钟消化吸收的动态变化；四种锌化合物在不同剂量（７．６、１５、３０、６０ｍｇ／ｋｇＨ２Ｏ）时组织中的储存。结果：以相同浓度的锌灌胃（６．０ｍｇ／ｋｇｂｗ），甘氨酸锌入血快于其它三个锌化合物，在１５分钟时达到最高峰（１００μｍｏｌ／Ｌ），乳酸锌和葡萄糖酸锌３０ｍｇ／ｋｇ时吸收峰值最大（６６．０μｍｏｌ／Ｌ，７９．５μｍｏｌ／Ｌ）；硫酸锌则在６０分钟到达高峰（７８．９μｍｏｌ／Ｌ）。用不同剂量锌（１５、３０、６０ｍｇ／ｋｇＨ２Ｏ）喂养幼鼠，甘氨酸锌在１５ｍｇ／ｋｇ、乳酸锌和葡萄糖酸锌３０ｍｇ／ｋｇ时血和组织中吸收峰值最大，且成直线关系；而３０、６０ｍｇ／ｋｇ时血和组织中浓度则基本保持恒定。而硫酸锌的吸收与剂量浓度关系成正比。以硫酸锌的吸收为１００％，用药物代谢动力学软件３Ｐ８７计算葡萄糖酸锌、乳酸锌和甘氨酸锌相对生物利用率分别为：１３２％、７３％和１２４％。     

Reduced cadmium body burden in cadmium-exposed calves fed supplemental zinc

The objectives of this study were to evaluate the use of practical supplemental dietary zinc to modify the cadmium content in edible bovine tissues and to identify copper interactions with cadmium and zinc. The effect of supplemental zinc (200 or 600 μg/g) on the concentrations of cadmium, zinc, and copper in liver, kidney cortex, muscle, and blood of calves fed 50 μg/g cadmium for 60 days was evaluated. Blood samples were collected before and eight times after starting to feed cadmium or cadmium plus zinc. Liver, kidney, and muscle samples were collected when calves were slaughtered (baseline, at beginning of experimental feeding; cadmium-fed, at end of 60 days feeding). The cadmium concentrations of all sample types collected were markedly increased by the feeding of cadmium. Feeding 600 μg/g supplemental zinc significantly increased the zinc concentrations of liver, kidney cortex, and blood and decreased the cadmium accumulation in these organs as well as muscle. The copper concentrations of muscle or blood were not altered by feeding cadmium with or without zinc but those of liver and kidney cortex were significantly increased by higher dietary levels of zinc and cadmium. The potential use of dietary zinc salts in reducing cadmium body burden in food animals suspected or known to have high cadmium intakes is suggested.     

Effects of dietary phytic acid on lead and cadmium uptake and depletion in rats

Rats were given a semipurified diet supplemented with phytate (10 g/kg) or calcium (6 g/kg) and lead (200 mg/kg) or cadmium (5 mg/kg) for 4 weeks. Addition of phytate or calcium reduced the accumulation of lead in bone (P less than 0.001) and in blood and liver samples (P greater than 0.05). The greatest inhibition of tissue lead retention was evident when phytate and calcium were fed together. Cadmium accumulation was measured in the liver and kidney and was increased (P less than 0.05) by the addition of calcium. Phytate inhibited the increase in tissue cadmium promoted by calcium supplementation but did not otherwise influence tissue cadmium levels. In a further experiment, weanling rats were given diets supplemented with cadmium (5 mg/kg) or lead (200 mg/kg) for 4 weeks, and the accumulation of these elements in the body tissues was estimated in some animals. A phytate-supplemented (10 g/kg) or phytate-free semipurified diet (free of lead and cadmium) was then given to the remaining rats for 4 weeks. Phytate supplementation was found to have no significant effect on the rate of loss of lead or cadmium from tissues.     

Effect of food seasoning spices mixture on biomarkers of oxidative stress in tissues of fructose-fed insulin-resistant rats

High fructose feeding in normal rats induces insulin resistance and also facilitates oxidative damage. The present study examines the effects of a spices mixture (SM) on oxidative stress markers and antioxidant potential in tissues of high fructose-fed insulin-resistant rats. Male Wistar rats received a semisynthetic diet containing either 60% fructose or 60% starch. SM administration at three different doses (10, 30, and 50 mg/day per rat) was initiated orally 15 days later and continued for the next 30 days. After the total experimental period of 45 days, peroxidation of lipids and antioxidant status in liver and kidney were quantified. Fructose-treated rats showed increased levels of peroxidation indices such as thiobarbituric acid-reactive substances and lipid hydroperoxides in tissues. The condition was associated with an inadequate antioxidant system. Administration of SM along with fructose diet reduced the levels of peroxidation markers in tissues and improved the antioxidant status. The positive effect of SM on the oxidant-antioxidant balance could be attributed to the active constituents of the different spices present in the mixture.     

Effect of various cadmium doses in the diet on the body of growing rats

Studies were carried out on the effect of various cadmium doses, which were given to growing rats in diet. A 42-day biological experiment was carried out on male growing Wistar rats. The animals divided into groups were given diets containing cadmium in amounts of 50, 100 and 200 ppm and diet with no adding cadmium. The diets contained 20% of protein in equal amounts from wheat gluten and casein. It was demonstrated that cadmium had a significant influence on diet intake and growth of rats. The absorption from diets containing 50, 100 and 200 ppm of cadmium was about 30 to 48%. The more cadmium was absorbed, the most was in blood and rat liver. Anaemia was noted in animals, which were given diets with cadmium. Rats had a low level of haematocrit and haemoglobin in plasma. It was shown that cadmium intake caused a significant decrease in plasma albumin concentration and increase of plasma alanine aminotransferase and aspartate aminotransferase activity.     

Uptake and retention of dietary cadmium in mallard ducks.

Adult mallard ducks fed 0, 2, 20, or 200 ppm of cadmium chloride in the diet were sacrificed at 30-day intervals and tissues were analyzed for cadmium. No birds died during the study and body weights did not change. The liver and kidney accumulated the highest levels of cadmium. Tissue residues were significantly correlated in all treatment groups and residues increased with treatment level. Hematocrits and hemoglobin concentrations were normal in all groups throughout the study. Little cadmium accumulated in eggs of laying hens, but egg production was suppressed in the group fed 200 ppm.