镉对大鼠肾脏和睾丸毒性的比较

大鼠饮水中给镉12wk后,检测了尿低分子蛋白(LMWP)排出量。尿碱性磷酸酶(ALP)活性,血清睾酮水平,睾丸乳酸脱氢酶同功酶(LDH-X)活性,精子计数和形态,雄鼠生育力,肾,睾丸和附睾组织镉含量,并在光镜和电镜下观察上述组织的病理变化,从生化,形态和功能改变三方面比较了大鼠肾脏和睾丸对镉的敏感性,发现尿LMWP和ALP仅在高剂量组显著增加,而血清睾酮和睾丸LDH-X在中剂量纽和低剂量纽已明显降低,说明镉对睾丸的有害作用可出现在肾脏之前。     

Protection of melatonin against damage of sperm mito-chondrial function induced by reactive oxygen species

Aim: To study the mitochondrial function damage of sperm in-duced by reactive oxygen species (ROS) and the protection of melatonin (MLT) against the damage. Methods: Normal function spermatozoa were selected from semen samples by Percoll gradi-ent centrifugation technique. The ROS generated by the hypoxan-thine xanthine oxidase system was incubated with the normal sper-matozoa in the presence or absence of MLT (6 retool/L) for 30 and 60 minutes.     

不同麻醉方法对开胸手术患者红细胞糖代谢限速酶活性的影响

目的 探讨开胸手术患者红细胞内糖代谢限速酶活性的变化及不同麻醉方法对其的影响。方法 48例ASAI～Ⅱ级择期开胸手术患者,按麻醉方式随机分成三组,每组16例。Ⅰ组采用地氟醚吸入为主的全身麻醉;Ⅱ组采用异氟醚吸入为主的全身麻醉;Ⅲ组采用异氟醚吸入联合连续硬膜外阻滞。于麻醉前、手术90min、术后60min及术后第1、2天共五个时点分别测定血糖浓度及红细胞6-磷酸葡萄糖脱氢酶(G-6PD)、磷酸果糖激酶(PFK)和醛糖还原酶(AR)活性。结果 与麻醉前比较,三组患者血糖浓度自术中90min开始,至术后第2天升高显著(P<0.05);Ⅰ、Ⅱ两组术后第1天PFK活性显著下降(P<0.05),G-6PD、AR活性显著升高(P<0.05),而Ⅲ组各时点红细胞内糖代谢限速酶活性的变化与麻醉前比较均无统计学差异(P>0.05),且Ⅲ组术后第1天PFK值远低于Ⅰ组相应值。结论 开胸手术中、手术后存在明显的高血糖反应。术后第1天,红细胞内会出现糖酵解途径受抑制,磷酸戊糖途径、多元醇通路相应活跃现象。采用异氟醚吸入联合硬膜外阻滞可在一定程度上调控手术创伤对红细胞糖代谢的影响。     

Histochemical study of mitochondrial enzymes in cerebellar cortex of macular mutant mouse,a model of Menkes kinky hair disease

The cerebellar Purkinje cells in the hemizygote of the macular mutant mouse contain numerous abnormal mitochondria which show a marked decrease in cytochrome c oxidase activity. Using histochemical methods we studied the activity of other mitochondrial enzymes, such as NADH diaphorase and succinic dehydrogenase, in the cerebellar cortex of this mutant mouse. Such activities were markedly increased in the Purkinje cells, especially in the soma and stem dendrite, from 10 days after birth in the hemizygote as compared with findings in normal littermates. These results were considered to be due to an increased number of abnormal mitochondria.Supported by the Research Grants nos. 2A-5-03 and 3B-1-04 for Nervous and Mental Disorders from the Ministry of Health and Welfare, and by Grant no. 04670492 of the Ministry of Education of Japanese Government     

Reduced 293T cell susceptibility to acrolein due to aldose reductase-like-1 protein expression.

Acrolein is a highly reactive alpha,beta-unsaturated aldehyde produced endogenously during lipid peroxidation and naturally distributed pervasively in living environments, posing serious threats to human health if not properly metabolized. In this study, we report aldose reductase-like-1 (ARL-1) as a novel enzyme that catalyzes the reduction of acrolein and protects cells from their toxicity. Using purified ARL-1 protein, we determined its enzymatic activity in response to acrolein and defined its steady-state kinetics with K(m) and V(max) at 0.110 +/- 0.012 mM and 3122.0 +/- 64.7 nmol/mg protein/min, respectively. By introducing a functional Enhanced Green Fluorescent Protein (EGFP)/ARL-1 fusion protein into 293T cells, we demonstrated that plating efficiency in liquid culture and focus formation in soft agar increased by more than 60% (p < 0.05), compared to the vector control cells. More significantly, at a low dose of 5 microM acrolein, EGFP/ARL-1 expression enhanced both plating efficiency and focus formation by more than threefold, and the foci (in soft agar) of 293T cells expressing EGFP/ARL-1 were significantly larger than those of the vector control cells. At high concentrations of acrolein (25 and 50 microM), EGFP/ARL-1 protein prevented oncotic death of 293T cells induced by acrolein. In summary, our data demonstrated for the first time that the ARL-1 protein protects 293T cells from acrolein toxicity. Due to the high toxicity and wide distribution of acrolein, this finding is important to the understanding of its detoxification mechanisms.     

维生素E琥珀酸酯诱导人胃腺癌细胞凋亡途径

目的　探讨维生素E琥珀酸酯 (VES)诱导人胃腺癌SGC -790 1细胞凋亡的死亡受体 (Fas)信号转导途径。方法　人胃腺癌SGC -790 1细胞经不同剂量VES(5,10 ,2 0 μg/ml)处理 ,同时做琥珀酸、维生素E和空白对照 ,采用DAPI(4,6-贰脒基 -2 -苯基吲哚 )荧光染色法观察细胞凋亡情况 ,用WesternBlot法检测Fas、带有死亡结构域的Fas相关蛋白 (FADD)和天冬氨酸特异性半胱氨酸蛋白酶 (caspase -8)蛋白表达情况 ,Fas和FADD反义寡聚核苷分别转染SGC -790 1细胞后 ,用荧光法检测caspase -8活性。 结果　经VES处理后的细胞DAPI染色可见凋亡的形态学改变 ,2 0 μg/mlVES处理 48h后的细胞凋亡率为 89.6% ;VES处理 48h后Fas、FADD和caspase -8蛋白表达明显增加 ,且呈剂量 -效应关系 ;阻断Fas可明显抑制FADD蛋白表达 ,Fas和FADD反义寡聚核苷转染细胞后caspase -8活性明显降低 (P <0 .0 1) ,其中阻断Fas的效果高于阻断FADD。结论　维生素E琥珀酸酯诱导人胃腺癌SGC -790 1细胞凋亡过程中启动了Fas信号转导途径 ,VES启动Fas后 ,FADD将Fas和caspase -8联接起来 ,活化caspases级联反应 ,从而构成Fas/FADD/caspase -8的凋亡信号途径     

耐药性癫患者脑组织线粒体mMDHNDUFC_2基因表达异常

目的研究耐药性癫患者脑细胞线粒体mMDH、NDUFC2表达,探讨其在耐药性癫癎形成中的作用。方法分别提取48例耐药性癫癎患者、8例非耐药性癫患者及8例对照组脑组织标本的总RNA后,用基因芯片对其进行扫描,随后用荧光定量PCR技术进行验证。结果发现与线粒体功能有关的基因mMDH、NDUFC2在耐药性癫癎中显著下调,荧光定量RT—PCR验证结果与基因芯片一致。结论脑细胞线粒体基因mMDH、NDUFC2表达异常可能通过能量代谢及神经元坏死参与了耐药性癫癎的形成。     

Pathogenesis of progressive muscular dystrophy: studies on free radical metabolism in an animal model

Evidence to suggest the presence of abnormal metabolism of oxygen free radicals in progressive muscular dystrophy is presented using an animal model. In the superficial pectoral muscles of dystrophic chickens, enzyme activities regulating the metabolism of oxygen free radicals, i.e., catalase, superoxide dismutases and glutathione peroxidase, were significantly elevated within 1 week of hatching. Activities of related enzymes, i.e., glutathione reductase, glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase were also elevated. In contrast, the specific activity of phosphofructokinase, the rate-limiting enzyme of the glycolytic pathway, was normal during the first 4-week period. These results suggest that there is an increased turnover of oxygen free radicals in the dystrophic muscle. This concept appears important in a further investigation of the pathogenesis and treatment of progressive muscular dystrophies.     

In vivo 13C saturation transfer effect of the lactate dehydrogenase reaction.

Lactate dehydrogenase (LDH, EC 1.1.1.27) catalyzes an exchange reaction between pyruvate and lactate. It is demonstrated here that this reaction is sufficiently fast to cause a significant magnetization (saturation) transfer effect when the 13C resonance of pyruvate is saturated by a continuous-wave (CW) RF pulse. Infusion of [2-(13)C]glucose was used to allow labeling of pyruvate C2 at 207.9 ppm to determine the pseudo first-order rate constant of the unidirectional lactate-->pyruvate flux in vivo. During systemic administration of GABAA receptor antagonist bicuculline, this pseudo first-order rate constant was determined to be 0.08+/-0.01 s-1 (mean+/-SD, N=4) in halothane-anesthetized adult rat brains. In 9L and C6 rat glioma models, the 13C saturation transfer effect of the LDH reaction was also detected in vivo. Our results demonstrate that the 13C magnetization transfer effect of the LDH reaction may be useful as a novel marker for utilizing noninvasive in vivo MRS to study many physiological and pathological conditions, such as cancer.