Inhibition of P-glycoprotein transport: a mechanism for endocrine disruption in the channel catfish?     

Kleinow KM  Hummelke GC  Zhang Y  Uppu P  Baillif C 《Marine environmental research》2004,58(2-5):205-208

P-glycoprotein (pgp), an efflux transporter localized in a variety of tissues including the intestinal mucosa, renal tubules and bile canaliculi, is known to participate in the disposition of a variety of chemicals, including steroid hormones. This study examined the relationship of pgp to the movement into the bile of the hormone estradiol (E2), and the potential for transport interactions between the environmental pollutant nonylphenol ethoxylate (NPE) and E2. Biliary-cannulated in situ-prepared isolated perfused livers were used to assess pgp transport function. E2, in competitive transport preparations with Rhodamine 123 (Rho123), a pgp substrate, demonstrated significant decreases in Rho123 transport into bile, as did the prototypic inhibitor and substrate verapamil. [3H]E2 (0.28 nM) transport into bile was significantly reduced with either 20 M NPE or verapamil. These results suggest that E2 is a substrate and/or modulator for the catfish biliary pgp transporter, and that NPE potentially influences biliary transport and excretion of E2.  相似文献   

Using trace elements in skin to discriminate the populations of minke whales in southern hemisphere     

Kunito T  Watanabe I  Yasunaga G  Fujise Y  Tanabe S 《Marine environmental research》2002,53(2):175-197

Concentrations of 12 trace elements (V, Cr, Mn, Cu, Zn, Se, Rb, Sr, Cd, Cs, Ba, and Hg) were determined in liver and skin tissues of minke whales from various regions within the Antarctic Ocean. Cd concentrations in livers of southern minke whale were apparently higher than those in cetaceans from other regions, while Hg concentrations were lower. There were significant positive correlations between body length and concentrations of Cd and Hg in the liver. The concentrations of all trace elements in the skin were lower than those in other cetaceans reported previously. Significant positive correlations between liver and skin were found for Cr, Mn, Cu, Zn, Rb, Cd, and Cs, implying that the concentrations of these trace elements in the skin reflect those of internal organs. Large interannual variation of the accumulation pattern of trace elements in the skin was observed for the southern minke whales from Area V. There were significant differences in the skin element concentrations among Areas III, IV, and V, especially for males. Also, discriminant analysis between geographically two different groups collected during 1995/1996 austral summer season, based on the concentrations of trace elements in the skin, allowed for a correct classification of 90% of these minke whales. These results suggest that measurement of trace elements in skin samples could provide valuable information on the status of contamination and possible geographic differences in the accumulation levels in southern minke whales.  相似文献   

日本岛弧背景中的石油资源   总被引：1，自引：0，他引：1  

Kikuc.  Y 康继本 《海洋地质译丛》1992,(4):22-25

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几个风暴潮预报模型的实例     

P.朗西奥尼  J.P.邦凱  Y.科埃费  顾伟浩 《海洋预报》1985,(1)

对给定的地点,可应用几种定型的模型正确地预报潮位。然而,在风暴条件下,潮位的观测值和预报值之间存在着差值,这个差值称作风暴潮。对位于塞纳河河口的勒阿弗尔港,同时用二种风暴潮预报模型:自回归模型和一种需用当地风、气压资料的模型。 自回归模型能用来作时效为5小时的预报;用勒阿弗尔气象台36小时内的风,气压的预报值,便可用第二种预报模型,给出39小时时效的风暴潮预报。  相似文献   

The impact of oestrogenic and androgenic contamination on marine organisms in the United Kingdom--summary of the EDMAR programme. Endocrine Disruption in the Marine Environment     

Matthiessen P  Allen Y  Bamber S  Craft J  Hurst M  Hutchinson T  Feist S  Katsiadaki I  Kirby M  Robinson C  Scott S  Thain J  Thomas K 《Marine environmental research》2002,54(3-5):645-649

This paper summarises results of the EDMAR programme which is investigating oestrogenic and androgenic endocrine disruption in UK coastal waters. Most of the data concern fish. Four species (flounder, viviparous blenny and two sand gobies) are experiencing feminisation in industrialised estuaries. In males this includes vitellogenin (VTG) synthesis, ovotestis induction and/or feminised sexual characteristics. Although reproductive success may be impaired in some cases, implications for fish populations are still unclear. Suspected causative contaminants include natural oestrogenic substances and synthetic oestrogen mimics. The majority of the oestrogenic activity is adsorbed to sediments, and routes of exposure may include benthic food chain transfer. Some natural androgenic substances are also being discharged to estuaries, but their activity appears low.  相似文献   

软流圈贯入—日本海弧后盆地张开机制   总被引：1，自引：0，他引：1  

Tatsu.  Y 张琴华 《海洋地质译丛》1990,(4):28-35

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Effect of an exotic prey on the feeding pattern of a predatory snail   总被引：2，自引：0，他引：2  

Rilov G  Gasith A  Benayahu Y 《Marine environmental research》2002,54(1):85-98

The mussel Brachidontes pharaonis, which invaded the Mediterranean from the Red Sea about 120 years ago, has recently become abundant in many midlittoral and some infralittoral rocky habitats along the Israeli rocky shore. We investigated the influence of B. pharaonis, as a novel prey, on the foraging patterns of the large whelk Stramonita haemastoma in the field, and examined food preferences in the laboratory. S. haemastoma has shifted from indigenous species to feeding on the novel mussel when abundant. The whelk prefers to prey upon the invasive mussel over all indigenous species offered (e.g. barnacles and mussels), probably due to its larger size. In the midlittoral zone, the foraging activity of S. haemastoma is considerably low even where refuges are readily available (incisioned-rocks) and food density is high (mainly B. pharaonis). Higher proportions of whelks are actively foraging in the infralittoral zone but usually on smaller prey, mostly barnacles. We suggest that this differential foraging activity in the two zones is related to the degree of exposure to wave action. The midlittoral is inherently more exposed to wave action than the infralittoral, where sea conditions are more benign and the whelks may enjoy longer activity periods.  相似文献   

A growth model for a hyalid amphipod Hyale perieri in the coastal water of Alexandria (Egypt)     

Zakaria H. Y  Dowidar N. M.  El-Komi M. M.  Atta M. M. 《海洋学报(英文版)》2003,22(2):221-231

Abstract-The growth rate of the hyalid amphipod Hyale perieri was studied on the bases of Ikeda'sgrowth model which is based on the inter moult period (IP) and moult increament (ΔBL). To applythis approach, laboratory experiments were carried out at three temperatures regimes (15℃, 20℃,25℃) to gain accurate data of IP and BL. The total number of specimens used in this study was 86 at15℃, 24 at 20℃ and 70 at 25℃. The number of flagellar segments of both antennae of the Hyaleperieri could not be used as an index of growth (instar criterion). The obtained results indicated that,the predicted IP of the specimens was inversely related to temperature and in good agreement with theobserved values at the experimental temperatures. IP data obtained from laboratory-reared specimes arecombined with ΔBL data to establish a growth model for Hyale perieri from its release from the mar-supium (1.64 mm BL) to the maximum size (12.67 mm BL) as a function of temperature. The maxi-mum numbers of consecutive moults  相似文献   

Tributyltin and triphenyltin induce spermatogenesis in ovary of female abalone,Haliotis gigantea   总被引：1，自引：0，他引：1  

Horiguchi T  Kojima M  Kaya M  Matsuo T  Shiraishi H  Morita M  Adachi Y 《Marine environmental research》2002,54(3-5):679-684

Two-month flow-through exposure experiments of tributyltin (TBT) and triphenyltin (TPhT) were conducted with abalone, Haliotis gigantea. Nominal concentrations of 100 ng TBT/l and 100 ng TPhT/l caused significant spermatogenesis in ovaries of exposed females. There were also significantly more contracted primary oocytes observed in females exposed to either TBT or TPhT than controls. The incidence of two types of unknown cells was also significant in females exposed to TPhT. No significant histological changes were observed in testis of exposed males. This ovarian spermatogenesis caused by TBT and/or TPhT resembles gastropod imposex. Remarkably high concentrations of TBT and TPhT were observed in the head (including central nervous system ganglia), compared to muscles concentrations. Accumulation of TBT and TPhT in the head may disturb reproductive hormonal regulators through neuropeptides released from ganglia. This, as well as possible aromatase inhibition, may be one of the inducers for spermatogenesis in the abalone ovaries.  相似文献   

Minor constituents in the Martian atmosphere from the ISM/Phobos experiment     

Rosenqvist J  Drossart P  Combes M  Encrenaz T  Lellouch E  Bibring JP  Erard S  Langevin Y  Chassefiere E 《Icarus》1992,98(2):254-270

Global Martian atmospheric results derived from the infrared imaging spectrometer ISM flown aboard the Phobos 2 Soviet spacecraft are presented. Over low altitude regions the expected CO mixing ratio of (8 +/- 3) x 10(-4) is measured. Variations of the 2.35-micrometers feature are inconsistent with this value over the Great Martian Volcanoes. If the 2.35-micrometers band is entirely attributable to carbon monoxide, the CO mixing ratio is typically depleted by a factor of 3 over these high altitude areas. Orography should play a major role in the existence of this CO "hole." If, however, these spectral variations at 2.35 micrometers are due to the surface composition, the fraction of the surface covered by the responsible mineral must smoothly decrease as the surface elevation decreases. This phenomenon implies a strong interaction between the surface and the atmosphere for the Great Martian Volcanoes. Diurnal behavior and latitudinal variations of water vapor are globally consistent with Viking measurements. During the Phobos observations, the water vapor amounts over the bright equatorial regions range around 11 pr-micrometers during the day. These amounts are slightly larger than those inferred from 1976 to 1979. The lack of global dust storms during 1988-1989 could explain the enhancement of H2O in the atmosphere.  相似文献