共查询到20条相似文献，搜索用时 171 毫秒
1.
W. R. Hartley A. Thiyagarajah M. B. Anderson M. W. Broxson S. E. Major S. I. Zell 《Marine environmental research》1998,46(1-5)
The purpose of this research was to evaluate the Japanese medaka (Oryzias latipes) as an ecotoxicological model for the rapid evaluation of environmental estrogens. A novel short-term (48-h) exposure to 17 β-estradiol is proposed in development of a positive control for disruption of gonadal development. Recently hatched medaka fry (30 fry per dose group) with undifferentiated gonads were exposed to 4.0, 29.4, and 115.6 μg/liter of 17 β-estradiol (acetone carrier) for 48 h in a water bath at 25 °C. The fry were then grown-out in spring water for 2 weeks, killed, and processed for histological evaluation. High lethality was encountered during the grow-out period in the 115.6 μg/liter dose group. Fry in the spring water and acetone (carrier) control groups developed into females or males. Fry exposed to 17 β-estradiol developed primarily into females or had testis-ova. 相似文献
2.
Pathology of the liver, kidney and gonad of flounder (Platichthys flesus) from a UK estuary impacted by endocrine disrupting chemicals. 总被引：1，自引：0，他引：1
M G Simpson M Parry A Kleinkauf D Swarbreck P Walker R T Leah 《Marine environmental research》2000,50(1-5):283-287
The Mersey estuary is highly contaminated with xenobiotics compared to the nearby Dee estuary. Male flounder, a migratory flatfish caught in the Mersey frequently contains high blood concentrations of the oestrogen controlled, female protein vitellogenin, suggesting that Mersey flounder have been exposed to endocrine disrupting contaminants. Males caught from the Dee contain lower blood vitellogenin levels. Preliminary histopathological examination of 410 flounder from both estuaries, focuses on the liver, kidney and gonads. Hepatic tubular vacuolation, foci of cellular alteration, and hepatocellular tumours were seen. Renal and gonadal pathology included the presence of two Mersey fish with enlarged and abnormal glomeruli, three phenotypic male Mersey flounder with unilateral intersex gonads and one male with bilateral, abnormal ovarian follicular components in the testis. These initial results provide pathological evidence of xenobiotic exposure in flounder sampled from both estuaries. Preliminary findings from flounder sampled from Millport, an offshore site in Southwest Scotland, showed no histopathological evidence of xenobiotic exposure. 相似文献
3.
Triclosan is an antibacterial agent commonly used in industry and often detected in waste-water effluent. The potential of triclosan to act as an endocrine disruptor was examined because its chemical structure closely resembles known non-steroidal estrogens (e.g. DES, bisphenol A). Japanese medaka fry (Oryzias latipes) were exposed for 14 days beginning 2 days post-hatch to triclosan (100, 10, 1 micrograms/l), 17-beta estradiol (E2; 1 microgram/l), or a solvent control (ethanol). Two months post-exposure, the phenotypic sex of each adult was assessed visually using sexually dimorphic fin shape and size. The proportion of females in each group was similar for triclosan-exposed animals and solvent-treated controls (ethanol 53%, 1 ppb 58%, 10 ppb 45%, 100 ppb 36%) although E2 treatment did produce 92% female adults. Sexually dimorphic fin traits were quantified to look for potential effects of triclosan and E2 on the development of secondary sexual characters. These results do not support the hypothesis that triclosan is potently estrogenic. However, changes in fin length and non-significant trends in sex ratio suggest triclosan is potentially weakly androgenic. 相似文献
4.
Mussels Mytilus galloprovincialis were exposed to different concentrations of estradiol (20, 200, and 2000 ng/l) in a semi-static regime (1-day dosing intervals) for up to 7 days in an attempt to see how mussels dealt with exogenous estrogenic compounds. Sex hormone levels were determined in whole tissue. Free-estradiol was only significantly elevated at the highest exposure dose (up to 10-fold). Most of the estradiol was in the tissues as fatty acid esters (> 78%), which sharply increased in a dose-dependent manner (from 4 ng/g in controls to 258 ng/g at the high exposure group). In contrast, neither free nor esterified testosterone levels showed significant differences between control and exposure groups. The results suggest the existence of mechanisms that allow mussels to maintain their hormonal status, and the important role that fatty acid esterification may play within those mechanisms. Synthesis and conjugation rates of estradiol were further investigated by measuring the activity of P450 aromatase, and palmitoyl-CoA:estradiol acyltransferase, in digestive gland microsomal fractions. Overall, the study contributes to the better knowledge of molluscan endocrinology, and defines new mechanisms of regulation of free steroid-levels in mussels. 相似文献
5.
Mussels Mytilus galloprovincialis were exposed to different concentrations of estradiol (20, 200, and 2000 ng/l) in a semi-static regime (1-day dosing intervals) for up to 7 days in an attempt to see how mussels dealt with exogenous estrogenic compounds. Sex hormone levels were determined in whole tissue. Free-estradiol was only significantly elevated at the highest exposure dose (up to 10-fold). Most of the estradiol was in the tissues as fatty acid esters (>78%), which sharply increased in a dose-dependent manner (from 4 ng/g in controls to 258 ng/g at the high exposure group). In contrast, neither free nor esterified testosterone levels showed significant differences between control and exposure groups. The results suggest the existence of mechanisms that allow mussels to maintain their hormonal status, and the important role that fatty acid esterification may play within those mechanisms. Synthesis and conjugation rates of estradiol were further investigated by measuring the activity of P450 aromatase, and palmitoyl-CoA:estradiol acyltransferase, in digestive gland microsomal fractions. Overall, the study contributes to the better knowledge of molluscan endocrinology, and defines new mechanisms of regulation of free steroid-levels in mussels. 相似文献
6.
湛江海域鱼类体内5种激素残留的放射免疫分析 总被引：1，自引：1，他引：0
本文采用放射免疫分析法分别测定了养殖与野生黑鲷、花尾胡椒鲷、军曹鱼、青鲈、白鲳5种常见湛江海域养殖鱼类肌肉中生长激素、雌二醇、孕酮、睾酮及绒毛膜促性腺激素的残留量。结果表明,在5种养殖与野生鱼类肌肉中均检出5种激素,各种激素的残留量依鱼类种类不同而有差异,在同种鱼类中的任一种激素残留量均是养殖鱼类显著高于相应的野生鱼类(P<0.01)。5种激素在5种养殖与野生鱼类中的残留情况是,生长激素均以养殖与野生青鲈最高,雌二醇以养殖黑鲷、野生军曹鱼最高,孕酮均以养殖与野生军曹鱼最高,睾酮均以养殖与野生白鲳最高,绒毛膜促性腺激素以养殖青鲈、野生花尾胡椒鲷最高。 相似文献
7.
本文通过qPCR方法,研究了我国重要海水鱼类——牙鲆（Paralichthys olivaceus）雌、雄成体组织以及性腺分化期的脑、性腺中gnrh1、gnrh2和gnrh3的表达水平。结果显示,gnrh1分布于所有检测的组织：在脑、垂体、肾脏和肝脏中高表达,在性腺中表达相对较低;gnrh2则在雌、雄性的肝脏以及雄性的肠、肾脏、眼睛和头肾中;而gnrh3只在雄性的肾脏、眼睛和肌肉中检测到微弱表达。人工诱导的牙鲆雌核发育鱼苗分别用17β-雌二醇（E2）和17α-甲基睾酮（MT）处理,使其分化为雌性或雄性个体表型。在性腺分化期的脑中,gnrh1的表达呈现上升趋势,在全长（total length,TL）4 cm鱼苗中,E2组的表达显著高于MT组（P<0.05）;gnrh2在2 cm TL时E2组显著高于MT组（P<0.05）,随后在E2和对照组的表达水平均出现下降趋势;gnrh3在2 cm TL时E2和对照组的表达均显著高于MT组（P<0.05）,自6 cm TL时MT和E2组的表达开始下降。在性腺中,三种gnrh在性腺分化前2 cm TL表达量都相对较高,随后呈现下降趋势。综上,推测牙鲆gnrh1可能参与了性腺分化的启动、分化过程及性腺发育,gnrh2主要参与了性腺分化的启动,gnrh3主要参与了性腺分化的启动和分化过程。 相似文献
8.
Comparative vitellogenic responses in three teleost species: extrapolation to in situ field studies. 总被引：5，自引：0，他引：5
Induction of vitellogenin (VTG) was compared among three teleostean species to determine their relative sensitivity of exposure to 17 beta-estradiol (E2). Japanese medaka (Oryzias latipes), sunshine bass (Morone saxatalis x Morone chrysops) and channel catfish (Ictalurus punctatus) were exposed to aqueous concentrations of E2 ranging from 10 to 100,000 ng/l for 21 days. Respective EC50 values for plasma VTG detected by western blot in medaka, catfish and bass were 200, 170 and 1560 ng E2/l. Since these EC50 values are based on VTG induction curves calculated relative to control values, they indicate differences in species' sensitivity to E2 exposure. Catfish and bass VTG responses obtained in laboratory exposures were compared to VTG responses previously observed with 21-day wastewater treatment plant effluent exposures. Plasma VTG induction in effluent-exposed fish ranged from 14 to 82% above reference values depending on species. Extrapolation of field responses with laboratory-exposed fish indicate catfish and bass were exposed to the equivalent of 27-240 ng E2/l in sewage effluent. 相似文献
9.
Peter Thomas 《Marine environmental research》1988,24(1-4)
To examine whether xenobiotics impair teleost reproduction by altering reproductive endocrine function, steroid hormone secretion and ovarian growth were investigated in female Atlantic croaker (Micropogonias undulatus) after chronic oral administration with sublethal doses of three classes of reproductive toxins (lead, benzo[a]pyrene and Aroclor 1254). All the sublethal treatments significantly impaired ovarian growth as assessed by the gonadosomatic index. Reduced ovarian growth was accompanied by a significant decline in circulating 17β-estradiol levels in fish exposed to lead and benzo[a]pyrene. All three toxicants significantly decreased plasma testosterone levels. However, the steroidogenic capacity of ovarian tissue in vitro was not altered by xenobiotic exposure. The data suggest that the decreased ovarian growth in croaker after pollutant exposure may be a consequence of the decline in plasma 17β-estradiol levels. Further, this decrease in circulating levels of gonadal steroids does not appear to be caused by a direct effect of the chemicals on ovarian steroid synthesis. 相似文献
10.
Scott AP Sanders M Stentiford GD Reese RA Katsiadaki I 《Marine environmental research》2007,64(2):128-148
Dab (Limanda limanda) caught in UK offshore waters show evidence of being exposed to estrogenic endocrine disrupters at a relatively low level. Two of 449 males caught between June and July 2005 had markedly elevated levels of vitellogenin (VTG; 21 and 750 microg/ml) and the remainder ranged from <0.01 to 8.6 microg/ml. Omitting the two outliers, there was a very significant positive relationship with the mass of individual males (a feature noted in previous studies on cod). Mean VTG concentrations in males differed significantly between sites. The site with the highest mean (1.6 microg/ml) was North East of the Dogger Bank and the site with the lowest (0.04 microg/ml) was in Cardigan Bay. Mean VTG concentrations in all North Sea fish were significantly higher than English Channel and Irish Sea fish, but this difference disappeared when fish mass was taken into account. VTG concentrations showed no relationship to water depth, stage of sexual maturity or age of the males. Sixty selected male plasmas were assayed for 17beta-estradiol but only two had measurable amounts (assay limit 0.04 ng/ml). Despite being the start of summer, the gonads of many of the males and females (especially those caught in the North Sea) showed signs of sexual maturity (presence of sperm in males and vitellogenic eggs in females). Many females had high VTG concentrations (up to 14 mg/ml) and 78 out of 80 had measurable concentrations of 17beta-estradiol. The cause of elevated VTG levels in male dab is unknown. As seen in cod, the presence of affected males does not appear to be linked to proximity to land or to known point sources of endocrine disrupters. However, our data, showing that larger fish are more likely to have elevated VTG concentrations, suggests a gradual accumulation by marine fish, probably through feeding, of persistent (probably relatively weak) estrogenic compounds. 相似文献
11.
采用放射免疫分析法测定了养殖与野生黑鲷Sparus macroccephalus、花尾胡椒鲷Plectorhynchus cinctus、军曹鱼Rachycentron canadum、青鲈Nibea japonica、白鲳Pampus argenteus5种湛江海域常见养殖鱼类肌肉中生长激素、雌二醇、孕酮、睾酮及绒毛膜促性腺激素的含量。结果表明,同一种激素含量依鱼种类的不同而有差异。5种激素在5种养殖与野生鱼类中的含量是,生长激素以养殖与野生青鲈最高,雌二醇以养殖黑鲷、野生军曹鱼最高,孕酮以养殖与野生军曹鱼最高,睾酮以养殖与野生白鲳最高,绒毛膜促性腺激素以养殖青鲈、野生花尾胡椒鲷最高。同一种激素含量在同种的养殖与野生鱼类中有显著差异(p<0.01),养殖黑鲷肌肉中5种激素含量分别是野生黑鲷的6.94、4.01、2.81、2.42、2.99倍;养殖花尾胡椒鲷分别是野生花尾胡椒鲷的5.68、2.51、2.15、2.13、1.93倍;养殖军曹鱼分别是野生军曹鱼的46.11、1.71、1.63、5.50、2.91倍;养殖青鲈分别是野生青鲈的6.60、2.75、2.83、3.58、5.38倍;养殖白鲳分别是野生白鲳的2.55、2.67、2.49、2.52、2.70倍。实验结果提示,放射免疫分析法可作为检测水产品中激素含量的有效手段。 相似文献
12.
13.
14.
The estuarine tapertail anchovy(Coilia nasus) is a high-value commercial fish. Estimating the spawning site or hatchery origin and habitat is essential for its conservation. This study aimed to determine the habitat use and life history characteristics of C. nasus from the Changjiang River Estuary. We investigated the environmental signatures of strontium(Sr) and calcium(Ca) in the otoliths of the collected specimens using electron probe microanalysis; additionally, we examined their gonadal mat... 相似文献
15.
Recent declines in Chesapeake Bay oyster populations have been attributed to disease, and reduced water quality from pollution. The stress associated with pollutant exposure may reduce energy available for growth and reproduction. Polychlorinated biphenyls (PCBs) are lipophilic contaminants that may potentially affect mobilization of lipid reserves, increasing reliance on glycogen stores, which could otherwise be utilized to supply energy for gametogenesis. Thus, PCBs may indirectly affect glycogen stores in oysters in a deleterious manner. To test for this effect, reproductively inactive oysters were exposed to PCBs by feeding individuals 0.7 g of algal paste containing 0, 0.35, or 3.5 micrograms PCBs daily for 8 weeks. Additionally, a group of oysters was exposed to PCBs (0, 0.35, and 3.5 micrograms) plus 0.3 g of non-toxic artificial sediment to examine interactive effects of sediment particles and PCBs. Adductor muscle, mantle, and gonadal tissues were analyzed for glycogen content. Results suggest that glycogen content is reduced in the adductor muscle with increasing PCB exposure, but there are no effects of PCBs in the mantle and gonadal tissues. 相似文献
16.
Elskus AA 《Marine environmental research》2004,58(2-5):463-467
Hepatic levels of the pollutant inducible enzyme, CYP1A, are strongly suppressed in spawning female fish, a phenomenon attributed to high plasma levels of the female sex steroid hormone, estradiol. To evaluate the contribution of estrogen metabolites to estradiol-mediated CYP1A regulation, we treated primary hepatocytes isolated from juvenile rainbow trout (Oncorhynchus mykiss) with vehicle, 17beta-estradiol, or the estrogen metabolite, estriol, alone and in combination with each other and with the potent CYP1A inducer, benzo[a]pyrene (B[a]P). We found dose-dependent suppression of B[a]P-induced CYP1A activity by both steroids relative to controls. At 10(-7) M doses, estradiol and estriol suppressed B[a]P-induced CYP1A activity by 3- and 2-fold, respectively. Although not statistically significant, mean basal CYP1A activity levels were 15- and 13-fold lower in estradiol and estriol treated hepatocytes, respectively, relative to vehicle treated controls. Combining doses of estradiol and estriol failed to produce synergistic suppression of either basal or B[a]P-induced CYP1A activity relative to treatment with either steroid alone. The observed suppression is well below the often strong suppression observed in spawning female fish. We conclude that factors in addition to estradiol and estriol are likely involved in producing sexual dimorphism in CYP1A expression observed in spawning fish. 相似文献
17.
Carvalho PS Kalil Dda C Novelli GA Bainy AC Fraga AP 《Marine environmental research》2008,66(1):205-207
Naphthalene (NAP) and phenanthrene (PHE) effects on Salminus brasiliensis, a carnivorous freshwater fish, were investigated using behavioral tests. Larval stages of S. brasiliensis were exposed to water concentrations of 0, 0.04 mg/l, 0.20mg/l and 0.50mg/l for naphthalene and 0, 0.01 mg/l, 0.05 mg/l and 0.1mg/l for phenanthrene during two developmental phases. The prey fish Prochilodus lineatus were not exposed. Visual acuity was measured at the end of phase 2 in individual S. brasiliensis, which were also tested at the end of each phase for number of attacks on prey, number of prey captured, prey capture efficiency, and distance swam. Vision was impaired by PHE exposure, as acuity angles increased in exposed fish. At Stage I 2.3+/-1.2 prey were captured with 46% efficiency in controls compared to 0.4+/-0.3 prey captured with 13.4% efficiency in fish exposed to 0.05 mg PHEl(-1), the LOEL for both endpoints. At Stage II 4.0+/-1.1 preys were captured in controls compared to 2.5+/-0.9 preys captured in fish exposed to 0.01 mg PHEl(-1), the LOEL. Stage II control fish captured prey with 70% efficiency compared to 30% efficiency at Stage II fish exposed to 0.05 mg PHEl(-1), the LOEL. Distance swam was not affected by either NAP or PHE exposure. The exposure of larval stages of S. brasiliensis to realistic water concentrations of PHE impairs foraging skills and could affect recruitment of the species. 相似文献
18.
Gonadal cysts of spotted gar (Lepisosteus oculatus), an air-breathing teleost commonly found in Louisiana waters, are described. Fish were collected from two sites: Bayou Trepagnier, a petroleum-contaminated site (30 males and 42 females), and Bayou Traverse, a control site (17 males and 15 females). After fish were evaluated for gross abnormalities, they were necropsied and the gonads, gonadal ducts, and gonadal cysts were evaluated histologically. Multilocular fluid-filled cysts were noted in the testes, or spermatic ducts of four spotted gars from the Bayou Trepagnier. Unilateral ovarian cystadenomas were present in one female from Bayou Trepagnier. No cysts were observed in the gonads of spotted gar from the control site. 相似文献
19.
光周期对松江鲈鱼生长和性腺发育影响的初步研究 总被引：1，自引：0，他引：1
在松江鲈鱼(Trachidermis fasciatus)生长和性腺发育的关键时期,挑选其同规格的幼苗分为长光照组(LL)与自然光照组(对照组,NL),研究光周期对其生长和性腺发育的影响。本研究将LL组与NL组分别设计3组平行,共计150尾。实验起始:LL组体质量:(3.7256±0.8236)g,全长:(6.2253±0.3687)cm;NL组体质量:(3.7179±0.7893)g,全长:(6.2053±0.3436)cm,组间体质量及全长差异不显著。经过76 d的光周期实验,在前中期体质量检测中,LL组体质量、全长大于NL组;最终LL组体质量:(29.0328±3.06437)g,全长:(13.2361±0.3861)cm;NL组体质量:(28.6639±2.4460)g,全长:(13.2684±0.6432)cm;LL组的肝指数均值为(9.1525±0.5053)%,相对于NL组的(5.2675±0.1504)%,为极显著(P0.001)。最终,LL组的性腺发育指数均值为(5.8150±0.1396)%,相对于NL组的(5.7625±0.3404)%,为极显著(p0.001)。LL组肝指数(HSI)、性腺发育指数(GSI)均显著高于NL组;卵巢从外观及卵径判断,LL组已发育至第V期,大部分卵粒饱满,卵粒清亮饱满相互黏连,而NL组卵巢为第IV期,颜色偏红且卵径显著偏小。LL组卵径均值为(1.2118±0.3136)mm,而NL组则为(0.8356±0.0935)mm,LL组卵径偏大(P0.001)。结果表明:在松江鲈鱼的幼鱼至成鱼阶段,即生殖洄游阶段,适当的延长光照对松江鲈鱼的性腺发育及肝脏能量储均存有显著性影响。 相似文献
20.
Eggs of rainbow trout (Salmo gairdneri Richardson) from five different lakes in North Island, New Zealand, were reared to discover whether they showed significant differences in survival which could be linked with DDT levels in the tissue. The muscle and gonads of pre‐breeding season fish and the parent females were assayed for DDT, as were the whole fry at the end of rearing. The highest DDT levels were found in fish from Lake Rerewhakaaitu, and eggs from these fish showed the least viability. Mortality was relatively low among eggs from fish out of the other lakes. Thus, DDT may possibly contribute to the high mortality found in eggs from Lake Rerewhakaaitu fish. 相似文献