镉负荷大鼠一氧化氮和肿瘤坏死因子-α释放在介导多器官机能活动障碍中的作用(英文)

Action of NO and TNF-α release of rats with cadmium loading in malfunction of multiple system organs

选择健康SD雄性成年大鼠36只,随机分成对照组(C组)、镉负荷中剂量组(M组)、镉负荷高剂量组(H组)。将分析纯CdCl_2·2.5H_2O用生理盐水稀释成含镉0.4mg/ml浓度的注射溶液,高压灭菌。M组和H组大鼠每天分别按合镉0.5和 1.0mg/kg体重腹腔注射染毒,C组用同样方法注射与H组同等剂量的生理盐水,进行急性镉负荷实验,连续观察7 d。研究急性镉负荷对大鼠血液及几种组织中一氧化氮(NO)自由基、肿瘤坏死因子--α(TNE-α)变化的影响及作用。结果显示:在整个实验期内,镉负荷大鼠体重与对照组比较明显下降;睾丸、心脏和肝脏组织中的镉含量极显著上升,并随镉负荷剂量和时间而增加;血浆NO水平M组虽高于对照组,但差异不显著,而H组极显著高于对照组,M和H组血浆TNF-α明显高于对照组;在整个实验期内,镉负荷大鼠睾丸、心脏和肝脏组织匀浆中NO较对照组高或明显高于对照组,睾丸和心脏组织匀浆中TNF-α也均高于或明显高于对照组,但肝脏中的TNF-α三组间没有差异。结果提示,镉负荷诱发NO、TNF-α大量释放在导致大鼠多种器官机能活动障碍发生过程中可能起重要作用。

Thirty-six healthy Sprague-Dawley male rats were used and divided randomly into a control group (group C ), amedium-dose cadmium loading group (group M) and a high-dose cadmium loading group (group H). Cadmium chloride wasdiluted with saline to contain 0. 4 mg/ml of autoclaved cadmium solution. Groups M and H were injected in the abdominalcavity with 0. 5 and 1. 0 mg of cadmium per kg body weight respectively, and group C with saline of the same dosage as ingroup H over 7 d. Six rats of each group were killed on the 4th day and 7th day after cadmium loading, respectively, andblood, testis, liver and heart were collected. Cadmium content, changes in nitric oxide and tumor necrosis factor-α were stud-ied in blood and the tissues of testis, liver and heart. Results showed that during the entire experimental period, body weightin groups M and H decreased significantly as compared with that in group C; cadmium concentration increased significantly intestis, heart and liver of groups M and H, and rose with increased dosage and time of cadmium loading; there was no obviousdifference in plasma nitric oxide between groups M and C, though nitric oxide was higher in group M than in group C. Nitricoxide in group H was significantly superior to that in group C. Plasma tumor necrosis factor-α was markedly higher in groupsM and H than in group C. Nitric oxide contents in the rat's testis, liver and heart homogenates with cadmium loading werehigher than those in group C or significantly superior to group C. The same changes in tumor necrosis factor-α in the tissue ho-mogenates of the testis and heart were found, but no obvious difference in tumor necrosis factor-α in the liver between the threegroups was observed. It is suggested that the massive release of nitric oxide and tumor necrosis factor-α induced by cadmiumloading may play an important role in the induction of malfunction of multiple systems or organs in rats.