4种南极冰藻中抗紫外辐射活性化合物类菌胞素类氨基酸(MAAs)的初步研究

目的研究和发现极端环境下南极冰藻中抗紫外辐射活性化合物。方法对4种生长较快的南极冰藻进行低温光照培养,同时采用UV-A和UV-B辐照胁迫,提取分离抗紫外辐射活性化合物;根据其理化性质、仪器分析数据初步确定各化合物的分子结构。并通过日光辐照活性组分,观察其降解速度,确定其抗紫外辐射活性。结果从南极绿藻Chlorophyceae L-4,硅藻Diatom HF-9中分别得到5种、7种活性化合物,其中6种属于类菌胞素类氨基酸(MAAs)类物质,并具有较强的抗紫外辐射活性。结论MAAs类物质在南极冰藻抗强紫外辐射过程中扮演重要角色。     

南极冰藻 Berkeleya rutilans H-15中清除自由基活性物质的分离纯化及其结构分析

目的 研究和发现极端环境下南极冰藻中清除自由基活性物质.方法 以南极冰藻Berkeleya rutilans H-15为试验材料,在国内外首先建立起了从南极冰藻中获取清除白由基活性物质的一套完整的方法,包括用甲畔提取活性化合物,用DPPH法和Godin法来追踪和检测活性化舍物的分离效果及变化情况,用硅胶柱层析对活性化舍物进行初步的分离和纯化,用Sephadex LH柱层析来进一步纯化,通过高效液相来进行化舍物纯度检测,高纯度化舍物用红外光谱和液质联用方法来确定化合物的类型和有关的功能基团.结果 在Berkeleya rutilans H-15中获得了一个纯的活性化舍物,经红外光谱和液质联用图谱初步进行分子结构分析,推测此化合物属于酚类化舍物,并具有很强的清除自由基的活性.结论 在南极冰藻中寻找并获得高活性的抗氧化剂是完全可行的.     

2—乙氧基乙醇染毒大鼠的睾丸苛些生化指标变化

目的 观察EE急性染毒大鼠睾丸某些酶活性和血清睾酮水平变化。探讨2-乙氧基乙醇（EE）致睾丸损伤的可能机理。方法 用EE800、1600和3200mg/Kg灌胃染毒,测定雄性Wister大鼠在染毒后6、12、24和48h血清睾酮含量和睾丸匀浆葡萄糖-6磷酸脱氢酶（G-6-PD）、山梨醇脱氢酶（SDH）及酸性磷酸酶（ACP）活性。结果 大鼠睾丸绝对重量、血清睾酮含量及睾丸匀浆G-6-PD、SDH及ACP活性均（极）显著下降。G-6-PD和SDH活性与血清睾酮含量呈（极）显著正相关。结论 推测EE的靶器官可能为睾丸,EE具有明显的雄性生殖毒性。     

Plasma catecholamine and corticosterone as well as brain catecholamine changes during coping in rats exposed to stressful footshock

Rats received 60 minutes of footshock that was escapable (coping group) or inescapable (noncoping group). Plasma taken by jugular catheter showed that noncoping rats, compared with coping rats, had significantly higher peak norepinephrine (NE) and epinephrine (E) concentrations and significantly longer elevation of these catecholamines after footshock. Similarly, plasma corticosterone levels remained elevated significantly longer after footshock in noncoping rats. In brain, hypothalamic NE concentrations were lower in noncoping rats compared with coping controls, and this difference remained for at least 30 minutes after shock. A fall in hippocampal NE concentration was seen only in coping rats once they learned to terminate shock. Our data indicate that neurochemical changes can be separated into changes due to the aversive nature of the stimulus and the ability to cope with a stressor. The inability to cope augments plasma catecholamine increases in response to a stressor and prolongs their return to baseline values. The latter is also true for corticosterone levels. The decrease in hippocampal NE in coping and the decrease in hypothalamic NE in noncoping rats is not due to footshock by itself but to the ability of the rat to terminate this stressor. No strong correlation between central and peripheral catecholamine changes became apparent except a possible negative correlation between hypothalamic NE and peripheral NE and E levels.     

氰戊菊酯染毒大鼠肺灌洗液中细胞与生化效应

给大鼠一次气管注入氰戊菊酯悬液(FS)以及中毒室内吸入氰戊菊酯(FA),通过分析BALF中细胞与生化组分评价肺脏的毒性反应。结果表明PAM_s数下降,PMN数、Alb和NANA含量增加,LDH、ALP和ACP活性升高,提示氰戊菊酯引起肺细胞生物膜损伤、弥漫性肺泡炎和肺水肿。氰戊菊酯的阈剂量和阈浓度分别为0.93 mg/kg和200 mg/m~3,阈下剂量和阈下浓度为0.19 mg/kg和40 mg/m~2。研究结果为探讨氰戊菊酯的肺脏毒性及其机理,为制订其卫生标准提供依据。     

Changes in rat lung structure and composition as a result of subchronic exposure to acrolein

Groups of Fischer-344 rats were exposed to either filtered air, 0.4, 1.4, or 4.0 ppm acrolein for 62 days (6 h/day, 5 days/week). Mortality was observed only in the 4.0 ppm chamber, where 32 of 57 male rats died, but none of the 8 exposed females died. The lungs of the 4.0 ppm group were heavier than those of the larger control animals. Relative to controls, there was a 20% increase in total dry lung weight while the percent dry weight decreased 1.5% in the high dose group. This increased dry weight and the absence of significant changes in the DNA and protein content per unit dry weight indicated that the greater lung weight observed in this group was in part due to increased cellularity. Lung connective tissue content was increased as a result of subchronic acrolein exposure. The amount of elastin per unit dry weight was 173% of control values in the animals exposed to 4.0 ppm acrolein. Collagen levels were elevated in both the 1.4 and 4.0 ppm groups, 113 and 137%, respectively, of control values. Histologically, the 4.0 ppm animals demonstrated bronchiolar epithelial necrosis and sloughing, bronchiolar edema with macrophages, and focal pulmonary edema. Exposure related lesions were observed in only 3 of the 31 rats examined from the 1.4 ppm chamber and in none of the animals exposed to 0.4 ppm acrolein.     

HPLC assays to simultaneously determine the angiotensin-AT1 antagonist losartan as well as its main and active metabolite EXP 3174 in biological material of humans and rats

Novel rapid and sensitive HPLC assays were developed to simultaneously determine losartan and its main active metabolite EXP 3174 in biological material of humans and rats following solid–phase or liquid–liquid extraction. The analytes were separated on a 3 μm particle-sized ULTREMEX™ CN column, which was preceeded by a 5 μm particle-sized guard column, using UV-detection at 245 nm. The assays provided high sensitivity with limits of quantification (LoQ) of 5 ng ml⁻¹ for both compounds in human and rat plasma and 10 ng ml⁻¹ in human and rat urine, respectively. In rat blood, bile and various tissues, limits of quantifications were achieved that ranged 10–15 ng per ml and per 100 mg tissue, respectively, for both analytes.     

Alterations in composition of field- and laboratory-developed estuarine benthic communities exposed to di-n-butyl phthalate

Macrobenthic animal communities developed in sand-filled aquaria in the laboratory and in the field were exposed to three concentrations of the plasticizer, di-n-butyl phthalate (DBP), and effects on community structure were assessed. Laboratory communities were colonized by planktonic larvae in unfiltered sea water; field communities, by naturally occurring animals. After 8 wk of colonization, laboratory and field communities (removed to the laboratory) were exposed to DBP for 2 wk. The numbers of individuals and species of animals in aquaria receiving 3.7 mg DBP/l (laboratory-colonized) or 3.8 mg DBP/l (field-colonized) were significantly less than those in control aquaria or in aquaria that received lower concentrations of the plasticizer. Affected phyla in laboratory or field faunal assemblages were chordates, mollusks, arthropods, and annelids. Amphipods, Corophium acherusicum, collected only from laboratory communities, also were significantly fewer in communities exposed to 0.34 mg DBP/l. Density of individuals and numbers of species were not affected by 0.04 mg DBP/l.     

Changes of gaseous exchange in the lung of mice acutely exposed to nitrogen dioxide

To clarify the acute effects of NO₂ on gaseous exchange in the lung of mice, O₂ and CO₂ concentrations in respiratory gas, respiratory rate (RR), arterial blood pH, Pa_CO2, Pa_O2, lung wet weight and lung water content were examined using the head-enclosed method. The results of the present study indicate that in mice exposed to 5 ppm NO₂ for 24 h the gaseous exchange in the lung and metabolic rate of O₂ and CO₂ in the body are accelerated, whereas in mice exposed to 10 ppm and 20 ppm NO₂ the gaseous exchange in the lung is inhibited to change the gaseous metabolism.