植物雌激素对鱼类影响的研究进展

植物雌激素是一类植物来源的具有雌激素活性的非甾族杂环多酚类化合物,也是一类潜在的环境内分泌干扰物,可以影响鱼类的生理、生殖等正常活动.本文介绍了植物雌激素的分布与来源,综述了各种植物雌激素对鱼类生长、行为和生殖的影响,并从植物雌激素与受体结合、抑制类固醇类激素的代谢、酶调节等几种可能的途径,讨论了植物雌激素对鱼类内分泌扰乱作用的机理.     

秀丽隐杆线虫在环境内分泌干扰物研究中的应用

模式生物秀丽隐杆线虫(Caenorhabditis elegans)具有繁殖速度快、世代周期短,通体透明、体细胞数目恒定,基因组小并被完全测序等优点,已经广泛地应用于生态毒理学研究。C.elegans的胚胎发育、蜕皮、繁殖等重要生理过程是通过激素调控的,外源激素的代谢产物可以作为核受体(NRs)的配体,C.elegans的寿命与胰岛素/胰岛素样生长因子信号(IIS)通路和固醇/类固醇信号通路密切相关。近年来已经建立了在分子、细胞、个体和种群水平上,利用vit-2、hsp、消化道与性腺、产卵数、胚胎发育时间、内禀增长率、性别比例等系统地筛选EDCs的指标体系。以C.elegans为模式生物,从线虫的蜕皮、IIS通路等角度探讨了EDCs对线虫寿命的影响及作用机制,并展望了C.elegans在EDCs导致的细胞增殖与细胞分化失调而诱发的癌症、糖尿病等研究中的应用前景。     

Effect of dietary genistein on growth performance,digestive enzyme activity,and body composition of Nile tilapia <Emphasis Type="Italic">Oreochromis niloticus</Emphasis>

An 8-week feeding experiment was performed to evaluate the effect of dietary genistein on growth performance, body composition, and digestive enzymes activity of juvenile Nile tilapia (Oreochromis niloticus). Four isonitrogenous and isoenergetic diets were formulated containing four graded supplements of genistein: 0, 30, 300, and 3 000 μg/g. Each diet was randomly assigned in triplicate to tanks stocked with 15 juvenile tilapia (10.47±1.24 g). The results show that 30 and 300 μg/g dietary genistein had no significant effect on growth performance of Nile tilapia, but the higher level of genistein (3 000 μg/g) significantly depressed the final body weight and specific growth rate. There was no significant difference in survival rate, feed intake, feed efficiency ratio or whole body composition among all dietary treatments. An assay of digestive enzymes showed that the diet containing 3 000 μg/ggenistein decreased stomach and hepatopancreas protease activity, and amylase activity in the liver and intestine, while a dietary level of 300 μg/g genistein depressed stomach protease and intestine amylase activities. However, no significant difference in stomach amylase activity was found among dietary treatments. Overall, the results of the present study indicate that a high level of dietary genistein (3 000 μg/g, or above) would significantly reduce the growth of Nile tilapia, partly because of its inhibitory effect on the activity of major digestive enzymes. Accordingly, the detrimental effects of genistein, as found in soybean products, should not be ignored when applied as an alternative ingredient source in aquaculture.     

环境内分泌干扰物诱导鱼类产生卵黄原蛋白的研究进展

目前已经被确认的环境内分泌干扰物达100余种,其中能够诱导鱼类产生卵黄原蛋白(Vitellogenin, VTG)的环境内分泌干扰物包括农药、多氯联苯类化合物、邻苯二甲酸酯类化合物等几大类.由于环境内分泌干扰物结构的复杂性,其诱导机制成为近年研究的热点.本文综述了能够诱导鱼类产生VTG的环境内分泌干扰物的种类、筛选方法及作用机制.     

Sexual characteristics of male guppies Poecilia reticulata serve as effect biomarkers of estrogens

Guppies( Poecilia reticulata) are considered a candidate model species for the identification and testing of endocrine-disrupting chemicals. Male guppies may be used to address the challenge of making potential linkages between alterations of biomarkers, both at the cellular and organ level, and adverse outcomes. In the present study, a predictive relationship between sex characteristics and reproductive output was observed in male guppies that underwent a long-term toxicity test with 0.5 μg/L 17 β-estradiol administered during the juvenile period. Radioimmunoassay and western blot analyses demonstrated that 17 β-estradiol exposure caused a significant increase in testicular 17 β-estradiol levels as well as the induction of exposure biomarkers, namely hepatic vitellogenin. Exposure to 17 β-estradiol also caused a significant decrease in testosterone levels, which consequently reduced the gonadosomatic index, sperm counts, and the coloration index. These changes of male sexual characteristics further translated into adverse influences on reproduction, as measured by a decrease in offspring production and survival rate. Our results suggest that the above-mentioned sexual characteristics of male guppies may be considered potential in vivo biomarkers of estrogen effects on reproduction.     

植物雌激素影响鱼类生殖发育的作用机理研究进展

植物雌激素(Phytoestrogen,PE)是一类植物来源的杂环多酚类化合物,在结构和功能上与17β-雌二醇(雌二醇)类似,能够结合雌激素受体,具有弱的雌激素活性.已发现的植物雌激素有40多种,主要分布于38科植物中,大致可归纳为10种结构类型,包括黄酮类、苯丙素类、蔗类、内脂或香豆素类、芳香醚类、生物碱类、三萜类...     

有机磷农药对胆碱能系统影响研究进展

有机磷农药具有高效、低毒等特点被广泛应用于农业生产,其残留对生物和人类的健康构成了潜在的威胁.由于有机磷农药主要通过影响胆碱能系统的活性发挥其神经毒性作用,因此本文综述了有机磷农药对胆碱能系统中乙酰胆碱脂酶、胆碱乙酰转移酶、毒蕈碱型受体和烟碱型受体产生的影响及可能的致毒机理.有机磷农药首先抑制乙酰胆碱脂酶的活性产生神经...     

海胆早期血清素能神经系统的发育及功能研究进展

海胆胚胎是研究神经发育生物学的理想生物模型。血清素能神经系统在海胆早期胚胎发育过程中形成最早,主要由血清素能顶端神经节和受体细胞网络构成,对海胆幼虫的游泳行为具有调控功能。本文对海胆幼虫血清素能顶端神经节和受体细胞网络的发育过程,以及血清素能神经系统的功能等方面进行了综述。     

海胆早期血清素能神经系统的发育及功能研究进展

海胆胚胎是研究神经发育生物学的理想生物模型.血清素能神经系统在海胆早期胚胎发育过程中形成最早,主要由血清素能顶端神经节和受体细胞网络构成,对海胆幼虫的游泳行为具有调控功能.本文对海胆幼虫血清素能顶端神经节和受体细胞网络的发育过程,以及血清素能神经系统的功能等方面进行了综述.     

刺参对人工礁体设计关键指标的选择性

采用平均聚集率(Mean Attractive Rate,MAR)作为统计分析指标,研究了仿刺参(Apostichopusjaponicas Selenka)对人工礁体结构设计关键指标(孔径、间隙、颜色、夹角)的选择性及其行为特性。结果表明:(1)随着实验时间延长,仿刺参在礁体模型上的聚集数量呈上升趋势;(2)礁体模型在自然光照条件下的聚参效果优于黑暗条件下的聚参效果(P<0.05);(3)孔径组各水平间聚参效果比较:2 cm>4 cm、16 cm>8 cm(P<0.05),4 cm与16 cm间差异不显著;间隙组各水平间聚参效果比较:2 cm>4 cm>6 cm>8 cm(P<0.05);颜色组各水平间聚参效果比较:黑色、蓝色、红色>绿色>白色>透明(P<0.05),黑色、蓝色、红色间差异不显著;夹角组各水平间聚参效果比较:15°>30°>45°、60°>90°、120°(P<0.05),45°与60°差异不显著,90°与120°差异不显著。说明仿刺参适应礁体模型需要一定时间,呈负趋光性。10 g至30 g的仿刺参,对设计指标为2 cm孔径、2 cm间距、深色、15°夹角的人工礁体,具有较好地选择性。