Modification by Polychlorinated Biphenyls(PCBs)of Cadmium Induced Lesions in the Planarian Model,Dugesia dorotocephala

作     者：LARRYG.HANSEN WAHEEDAM.TEHSEEN DAVIDJ.SCHAEFFER GEORGEL.FOLEY 

作者机构：DepartmentDepartmentDepartmentDepartment of Veterinary Biosciences of Veterinary Biosciences of Veterinary Pathobiology University of IUinois2001 S.Lincoln AveUrbanaIL 61801USA 

出 版 物：《Biomedical and Environmental Sciences》 (生物医学与环境科学（英文版）)

年 卷 期：1993年第6卷第4期

页      面：367-384页

核心收录：

学科分类：100405[医学-卫生毒理学] 1004[医学-公共卫生与预防医学(可授医学、理学学位)] 07[理学] 09[农学] 0903[农学-农业资源与环境] 0713[理学-生态学] 10[医学] 

主　　题：PCBs)of Cadmium Induced Lesions in the Planarian Model,Dugesia dorotocephala Modification by Polychlorinated Biphenyls 

摘      要：The appearance of abnormal growths on the planarian, Dugesia dorotocephala, in response to cadmium with and without pre-exposure to L-buthionine-R, S-sulfoximine (BSO) and concurrent exposure to the polychlorinated biphenyls (PCBs) Aroclor 1254, PCB 28, PCB 110 or PCB 126 is described. Pigmented rose thorn (PRT) lesions were non-invasive and appeared in response to PCBs. Post-head (PH) lesions developed in up to 100% of the animals within 6-20 days post-dosing, progressed rather rapidly and were highly invasive. Round tail tip (RTT) lesions appeared in lower frequencies within 10-30 days, but progressed extremely rapidly resulting in tail loss within 48 h. We have referred to these types of lesions as tumors , but they are not necessarily characteristic of vertebrate neoplasms. PCBs interacted with cadmium in a complex way, in some cases increasing total lesions and decreasing time-to-lesion and in other cases having the opposite effects. A three-factor (PCB, PCB dose, Cd dose) nested analysis of variance model was used to determine lesion rates in order to compare PCB potencies as potentiators or antagonists. The Aroclor mixture was always the least potent co-toxicant but appeared to be the most potent antagonist; the coplanar PCB 126 was the most potent co-toxicant. The complex response surfaces and the lack of stoichiometry in dose-response relationships indicate that multiple mechanisms are responsible for PH and RTT lesions in planarians. These results emphasize the complexity of PCB toxicities and suggest further studies to validate the planarian model as a screen for combinations or environmental mixtures which may have altered biological potency in other species.