The expression of CYP1A,vitellogenin and zona radiata proteins in Atlantic salmon (Salmo salar) after oral dosing with two commercial PBDE flame retardant mixtures: absence of short-term responses

The short-term effects of the commercial PBDE flame retardant mixtures Penta-BDE and cta-BDE on the expression of cytochrome P450 1A (CYP1A), vitellogenin (Vtg) and zona radiata proteins (Zrp) were investigated in juvenile salmon (Salmo salar). For this purpose, groups of fish were dosed twice (oral intake at days I and 4) with 10 and 50 mg/kg body weight of both commercial mixtures. The fishes were sacrificed at day 7 (n = 5 for each group) and 14 (n = 6 for each group), and blood, liver, fillet, and brain were collected. Blanks and positive controls were also part of the experiment. The expressions of Vtg, Zrp, and CYPIA were measured with several techniques (EROD, ELISA, Western, Northern and Slot Blot). The values in the groups of fish treated with Penta-BDE or Octa-BDE did not significantly differ from the reference group for any of the parameters tested. In contrast, the positive control groups treated with estradiol-17beta for Vtg and Zrp expression, and beta-naphthoflavone for CYP1A expression did show a significant response, indicating the potential sensitivity of the fishes for the parameters measured. Since the results of the chemical analyses showed concentrations of a number of PBDE congeners in liver, fillet, and brain that were about three orders of magnitude above those of fish from the North Sea, it is concluded that the short-term toxicity of both commercial PBDE mixtures for these endpoints was low.     

贝藻混养对大西洋鲑养殖废水的生物滤除

养殖废水的综合利用与无公害化处理排放是实现水产养殖业健康可持续发展的重要保障。作者采用太平洋牡蛎(Crassostrea gigas)及龙须菜(Gracilaria lemaneiformis)混养和单养的方式处理大西洋鲑工业化循环水养殖系统排放的废水,设置贝类组、藻类组、贝藻组3组处理,探讨了贝藻混养方式和贝类、藻类单养对废水中主要水质因子(N、P营养盐、化学需氧量(COD)和总悬浮颗粒物(TSS))的处理效率,实验周期为30 d。结果表明,牡蛎和龙须菜混养的方式处理养殖废水效果较好,其对氮、磷营养盐、COD及TSS的去除效率分别为:总氨态氮41.67%±8.82%、硝酸盐氮33.96%±0.34%、总磷7.18%±0.03%、COD 78.87%±1.82%和TSS 70.50%±1.65%,而亚硝酸盐氮出现一定的积累。综合分析,牡蛎和龙须菜混养的方式处理养殖废水的效率优于牡蛎和龙须菜的单独处理。     

超声成像技术在大西洋鲑早期性别及发育期鉴别的应用研究

采用KX-5100便携式B超机(7.5MHz高频线阵探头)对273尾1龄或2龄大西洋鲑(Salmo salar)的性别及性腺发育阶段进行了检测,同时对检测的大西洋鲑进行了解剖和取样,利用组织学观察法验证了超声成像技术对大西洋鲑雌雄性别和发育阶段的鉴别结果。研究结果显示:利用超声成像技术鉴别雌、雄大西洋鲑的平均准确率为86%,且鉴别雌鱼的准确率(93%)较雄鱼(81%)高。超声成像技术鉴别Ⅱ期+Ⅲ期、Ⅳ期、Ⅴ期卵巢的准确率分别为87%、92%和100%,鉴别Ⅱ期、Ⅲ期、Ⅳ期、Ⅴ期精巢的准确率分别为64%、71%、86%和84%。总体看来,超声成像技术鉴别早期性腺(Ⅱ期~Ⅲ期)发育的准确率较低,仅为75%,而对晚期性腺(Ⅳ期~Ⅴ期)发育鉴别的准确率较高,达到89%。     

Environmental estrogens interact with and modulate the properties of plasma sex steroid-binding proteins in juvenile Atlantic salmon (Salmo salar)

Environmental chemicals may modulate the endocrine system through interaction with plasma sex steroid-binding proteins (SBP) and SBP-regulated processes. Some of these chemicals, which are known to interact with the estrogen receptor (ER), were found to bind competitively to the Atlantic salmon (Salmo salar) SBP and potentially disrupt the endocrine function of these proteins. Furthermore, both weakly acting (di-n-butyl phthalate) and potent estrogen mimics (ethynylestradiol), were able to induce a substantial up-regulation of circulating levels of SBP in vivo. Interestingly, modulation of SBP-levels was found to be a more sensitive endpoint than chemically induced interference with classical ER-mediated mechanisms for weakly acting estrogen mimics like di-(n-butyl) phthalate. Interference with the endocrine function of SBPs may thus introduce a novel mechanism for endocrine disruption, and give additional answers to the question why some weakly acting xenoestrogens are causing “estrogen-like” reproductive disturbances in developing males.