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Effects of chlorinated hydrocarbons on bald eagle chicks
174
Abstracts
receptor activity. The results of this largely in vitro study increase our understanding of the consequences of hepatic CYPl Al induction, forewarn of reproductive impairment of sexually maturing fishes exposed to CYPlAl inducing compounds and argue for further, more detailed in vivo investigation. Partially funded by funds from the US National Cancer Institute, CA 45131 and by the US EPA Center for Ecological Health Research #CR819658.
Developmental, Behavioral and Reproductive Responses of Fishes to Endocrine Disrupting Xenobiotics: Observed and Potential Signals. W. P. DAVIS” & D. B. FOUSHEE.6 “Environmental Research Laboratory US EPA, Gulf Breeze, Florida 32561, USA; bBiology Department NC Agricultural & Technical State University, Greensboro, North Carolina 27411, USA.
Among fishes as well as vertebrates in general, there are many reports of anomalous developmental responses to xenobiotic and certain naturally occurring substances. Xenobiotically induced susceptibility to disease pathogens or neoplastic responses are frequently reported. Less well documented for fishes are investigations of xenobiotically induced changes of sex behavior or function. The idea of endocrine disruption from exposure to xenobiotic chemicals is emerging as a unifying concept to represent the diverse collective manifestations of xenobiotically induced impacts on the life histories of organisms. Demonstrating the validity of this concept requires careful design of experiments to effectively test potential interactions among different xenobiotic agents and the assessment of stages of susceptibility during complete life histories of both exposed organisms and progeny. The parameters to be used and definition of controls are especially crucial to each test. In this paper we compare several responses observed among fish studies and present potential avenues for future study.
Effects of Chlorinated Hydrocarbons on Bald Eagle Chicks. J. E. ELLIOTT,” R. J: NORSTROM; A. LORENZEN,b S. W. KENNEDY,b H. PHILIBERT,” J. J. STEGMAN,C G. D. BELLWARD,d L. E. HART & K. M. CHEN.e “Canadian Wildlife Service, Delta, British Columbia, V4K 3Y3, Canada; bCanadian Wildltfe Service, Ottawa, Ontario, KIA OH3, Canada; ‘University of Saskatchewan, Saskatoon. Saskatchewan, S7N 0 WO, Canada; dUniversity of British Columbia, Vancouver, British Columbia, V6T 124, Canada; eUniversity of British Columbia, Vancouver, British Columbia, V6T 123, Canada.
The effects of chlorinated
hydrocarbons
were studied in bald eagle (Haliaeetus leucocecoast of British Columbia, Canada. Based on previous work, nests were sampled within a gradient of exposure to chlorinated hydrocarbon pollutants, particularly from pulp mill point sources. Twentyfive eggs were placed in a laboratory incubator, of which 18 hatched and were sacrificed within 24 hours. Tissues were examined for a variety of morphometric, histological and biochemical endpoints of toxicity. Yolk sacs were analyzed for polychlorinated dibenzo-pdioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs) and organochlorines (OCs). Hatching success was lower (65%) in eggs taken from
phalus) chicks collected in 1992 from nests on the southern
Abstracts
175
pulp mill sites compared to reference sites (78%) although the difference was not statistically significant (x2 = 1.402). Concentrations of 2,3,7,8_substituted PCDDs and PCDFs were significantly higher in yolksacs collected near three pulp mill sites compared to those from reference areas. Elevated levels of PCBs, including non-ortho congeners, and organochlorine pesticides were present in yolksacs, but showed only minor differences among sites. Significant positive regressions were found for hepatic cytochrome P450 parameters and uroporphyrin levels with concentrations of 2,3,7,8-TCDD and 2,3,2’,7,8-TCDF in yolk sacs.
Interactions of Metallothionein and Vitellogenin Synthesis in Rainbow Trout. PER-ERIK OLSSON,” PETER KLING” & CHRISTER SILVERSAND. uDepartment of Cellular and Developmental Biology, Umea University, S-901 87 Umea, Sweden; bDepartment of Zoophysiology, University of Gbteborg, Medicinaregatan 18, 413 90 Goteborg, Sweden. Metallothioneins (MS) are a family of heavy metal binding proteins that are involved in the maintenance of trace metal homeostasis and the detoxification of heavy metals in a wide variety of organisms. We have previously shown that MT is endogenously regulated during the period of sexual maturation in rainbow trout. Cadmium has been shown to reduce the plasma levels of vitellogenin (VTG) in vitellogenic rainbow trout and winter flounder as well as in E2 treated flounder. To investigate the effects of cadmium on the regulation of MT and VTG in rainbow trout we treated fish with intraperitoneal injections of oestradiol-17P, in combination with cadmium or zinc and the metals on their own. Injection of cadmium or zinc induced the synthesis of MT while injection of oestradiol-17/3 induced VTG. Injection of oestradiol-17P in combination with cadmium resulted in inhibition of both VTG and MT transcription and translation. Chromatography revealed that cadmium, when co-injected with oestradiol-17/3, did not bind to metallothionein. However, in these fish cadmium was gradually redistributed to MT. This resulted in induction of MT synthesis, binding of cadmium to and subsequent induction of vitellogenin. The binding of cadmium to non-MT proteins repressed the induction of MT and resulted in increased toxicity of the metal. However, preinduction of MT by zinc injections resulted in decreased cadmium sensitivity of the fish and a reduction in the repression of VTG mRNA. Furthermore, a role for MT in the detoxification of cadmium is indicated by the induction of VTG synthesis that occurred once MT has begun sequestering cadmium.
Effects of DDT and PCB on Reproductive Endocrinology of Purufubrax chthrutus in Southern California. R. B. SPIES,” P. THOMASb & M. MATSUI.” “Applied Marine Sciences, 2155 Las Positas Court, Suite S, Livermore, California 94550, USA; bUniversity of Texas at Austin, Marine Science Institute, 750 Channel View Drive, Port Aransas, Texas 78373, USA; ‘VANTUNA Research Group, Occidental College, 1600 Campus, Dr., Los Angeles, California 90041, USA. Our objective was to determine if bioaccumulated PCB and DDT were influencing kelp bass reproduction on the Palos Verdes Shelf near Los Angeles. Field-exposed and laboratory-exposed female fish were evaluated for a series of endocrine measures including
Abstracts
receptor activity. The results of this largely in vitro study increase our understanding of the consequences of hepatic CYPl Al induction, forewarn of reproductive impairment of sexually maturing fishes exposed to CYPlAl inducing compounds and argue for further, more detailed in vivo investigation. Partially funded by funds from the US National Cancer Institute, CA 45131 and by the US EPA Center for Ecological Health Research #CR819658.
Developmental, Behavioral and Reproductive Responses of Fishes to Endocrine Disrupting Xenobiotics: Observed and Potential Signals. W. P. DAVIS” & D. B. FOUSHEE.6 “Environmental Research Laboratory US EPA, Gulf Breeze, Florida 32561, USA; bBiology Department NC Agricultural & Technical State University, Greensboro, North Carolina 27411, USA.
Among fishes as well as vertebrates in general, there are many reports of anomalous developmental responses to xenobiotic and certain naturally occurring substances. Xenobiotically induced susceptibility to disease pathogens or neoplastic responses are frequently reported. Less well documented for fishes are investigations of xenobiotically induced changes of sex behavior or function. The idea of endocrine disruption from exposure to xenobiotic chemicals is emerging as a unifying concept to represent the diverse collective manifestations of xenobiotically induced impacts on the life histories of organisms. Demonstrating the validity of this concept requires careful design of experiments to effectively test potential interactions among different xenobiotic agents and the assessment of stages of susceptibility during complete life histories of both exposed organisms and progeny. The parameters to be used and definition of controls are especially crucial to each test. In this paper we compare several responses observed among fish studies and present potential avenues for future study.
Effects of Chlorinated Hydrocarbons on Bald Eagle Chicks. J. E. ELLIOTT,” R. J: NORSTROM; A. LORENZEN,b S. W. KENNEDY,b H. PHILIBERT,” J. J. STEGMAN,C G. D. BELLWARD,d L. E. HART & K. M. CHEN.e “Canadian Wildlife Service, Delta, British Columbia, V4K 3Y3, Canada; bCanadian Wildltfe Service, Ottawa, Ontario, KIA OH3, Canada; ‘University of Saskatchewan, Saskatoon. Saskatchewan, S7N 0 WO, Canada; dUniversity of British Columbia, Vancouver, British Columbia, V6T 124, Canada; eUniversity of British Columbia, Vancouver, British Columbia, V6T 123, Canada.
The effects of chlorinated
hydrocarbons
were studied in bald eagle (Haliaeetus leucocecoast of British Columbia, Canada. Based on previous work, nests were sampled within a gradient of exposure to chlorinated hydrocarbon pollutants, particularly from pulp mill point sources. Twentyfive eggs were placed in a laboratory incubator, of which 18 hatched and were sacrificed within 24 hours. Tissues were examined for a variety of morphometric, histological and biochemical endpoints of toxicity. Yolk sacs were analyzed for polychlorinated dibenzo-pdioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs) and organochlorines (OCs). Hatching success was lower (65%) in eggs taken from
phalus) chicks collected in 1992 from nests on the southern
Abstracts
175
pulp mill sites compared to reference sites (78%) although the difference was not statistically significant (x2 = 1.402). Concentrations of 2,3,7,8_substituted PCDDs and PCDFs were significantly higher in yolksacs collected near three pulp mill sites compared to those from reference areas. Elevated levels of PCBs, including non-ortho congeners, and organochlorine pesticides were present in yolksacs, but showed only minor differences among sites. Significant positive regressions were found for hepatic cytochrome P450 parameters and uroporphyrin levels with concentrations of 2,3,7,8-TCDD and 2,3,2’,7,8-TCDF in yolk sacs.
Interactions of Metallothionein and Vitellogenin Synthesis in Rainbow Trout. PER-ERIK OLSSON,” PETER KLING” & CHRISTER SILVERSAND. uDepartment of Cellular and Developmental Biology, Umea University, S-901 87 Umea, Sweden; bDepartment of Zoophysiology, University of Gbteborg, Medicinaregatan 18, 413 90 Goteborg, Sweden. Metallothioneins (MS) are a family of heavy metal binding proteins that are involved in the maintenance of trace metal homeostasis and the detoxification of heavy metals in a wide variety of organisms. We have previously shown that MT is endogenously regulated during the period of sexual maturation in rainbow trout. Cadmium has been shown to reduce the plasma levels of vitellogenin (VTG) in vitellogenic rainbow trout and winter flounder as well as in E2 treated flounder. To investigate the effects of cadmium on the regulation of MT and VTG in rainbow trout we treated fish with intraperitoneal injections of oestradiol-17P, in combination with cadmium or zinc and the metals on their own. Injection of cadmium or zinc induced the synthesis of MT while injection of oestradiol-17/3 induced VTG. Injection of oestradiol-17P in combination with cadmium resulted in inhibition of both VTG and MT transcription and translation. Chromatography revealed that cadmium, when co-injected with oestradiol-17/3, did not bind to metallothionein. However, in these fish cadmium was gradually redistributed to MT. This resulted in induction of MT synthesis, binding of cadmium to and subsequent induction of vitellogenin. The binding of cadmium to non-MT proteins repressed the induction of MT and resulted in increased toxicity of the metal. However, preinduction of MT by zinc injections resulted in decreased cadmium sensitivity of the fish and a reduction in the repression of VTG mRNA. Furthermore, a role for MT in the detoxification of cadmium is indicated by the induction of VTG synthesis that occurred once MT has begun sequestering cadmium.
Effects of DDT and PCB on Reproductive Endocrinology of Purufubrax chthrutus in Southern California. R. B. SPIES,” P. THOMASb & M. MATSUI.” “Applied Marine Sciences, 2155 Las Positas Court, Suite S, Livermore, California 94550, USA; bUniversity of Texas at Austin, Marine Science Institute, 750 Channel View Drive, Port Aransas, Texas 78373, USA; ‘VANTUNA Research Group, Occidental College, 1600 Campus, Dr., Los Angeles, California 90041, USA. Our objective was to determine if bioaccumulated PCB and DDT were influencing kelp bass reproduction on the Palos Verdes Shelf near Los Angeles. Field-exposed and laboratory-exposed female fish were evaluated for a series of endocrine measures including