酚类化合物对小白鼠脾脏细胞DNA毒性的构效相关研究

应用彗星实验技术,测定了12种酚类化合物对小白鼠脾脏细胞DNA的损伤水平.应用Hansch法和量子化学MOPAC-PM3方法计算了12种酚类化合物的辛醇-水分配系数、分子折射率、分子最高占据轨道能和分子中最正原子电荷.运用SPSS统计软件进行回归分析,对小白鼠脾脏细胞DNA的损伤率进行了定量结构-活性相关研究(QSAR).结果表明,酚类化合物的亲脂性参数和分子折射率能有效地表征它们所引起的DNA的损伤程度.由化合物的电性效应引起的细胞毒性可忽略.     

羧基化多壁碳纳米管对雌性小鼠卵泡发育的影响

碳纳米管(carbon nanotubes, CNTs)作为一种新形式的结晶碳,在工业及医药领域具有非常广阔的应用前景。本研究采用水溶性较好的羧基化多壁碳纳米管(MWCNTs-COOH)为研究对象,探索功能化多壁碳纳米管对小鼠卵巢发育的影响。将羧基化多壁碳纳米管溶解在含0.5% Tween-20的磷酸盐缓冲溶液(PBS)中,对实验小鼠按照2.5, 5, 10 mg·kg-1进行持续64 d的灌胃处理。处理结束后通过透射电子显微镜和HE染色观察卵巢组织的形态学变化。结果显示,碳纳米管确实进入了小鼠卵巢中。同时,随着MWCNTs-COOH暴露的增加,雌性小鼠卵泡数量显著减少,而雌性小鼠卵泡的形态结构并无明显影响。     

Egg adoption can explain joint egg-laying in common eiders

Hypotheses regarding the evolution and maintenance of intraspecific nest parasitism were tested with data collected during a 3-year study of common eiders (Somateria mollissima) breeding near Churchill, Manitoba. The nest parasitism rate was highest (42.4% of nests) during the year with the highest nest density and the best environmental conditions, and lowest (20.2% of nests) in the year with the lowest nest density and the poorest environmental conditions. Over the nesting season, parasitic eggs were laid at the same time as normally laid eggs. Most parasitic eggs (>75%) were laid before the host female laid her third egg. The majority of the parasitic eggs were the first or second egg produced by the parasitic female. When a parasitic egg was laid before or on the same day as the host female initiated her clutch, the probability of her first egg being depredated before incubation was significantly lowered. First- and second-laid eggs suffered a high rate of predation probably because nesting females do not attend their clutch until their second or third egg is laid. Hypotheses that some females use intraspecific nest parasitism to parasitize the parental care of other females were inconsistent with these data. Egg adoption is a likely explanation for the prevalence of females incubating parasitic eggs in this population. Received: 30 September 1997 / Accepted after revision: 6 May 1998     

双酚A联合镉亚慢性染毒对未成年雌性小鼠生殖内分泌干扰作用

目前,针对双酚A(BPA)或镉(Cd)内分泌干扰毒性的研究很多,但是关于其联合作用的研究则较少。将昆明雌性幼鼠分为4组,分别为对照组、BPA组、Cd组及联合组,灌胃染毒5周,观察小鼠动情周期、卵巢组织抗氧化水平、血清性激素及子宫内膜下层α亚型雌激素受体(ERα)免疫组化表达等指标的变化。结果发现,与对照组比较,各染毒组的动情周期均发生变化,体重、子宫系数、血清性激素水平及子宫内膜下层ERα表达降低(P0.05);BPA组及Cd组的卵巢T-SOD及MDA水平与对照组比较无差异(P0.05),但联合组的卵巢T-SOD及MDA水平显著区别于对照组(P0.05);此外,联合组的子宫内膜下层ERα阳性表达率(36%±11.7%)显著低于BPA组及Cd组(P0.05)。BPA及Cd对雌性生殖内分泌系统联合作用毒性较各单剂量组增加,氧化损伤及影响ERα表达可能是联合毒性作用机制之一。