摘要:

DNA single‐strand breaks induced by procarcinogens were detected in Chinese hamster ovary (CHO) cells cocultured with adult rat hepatocytes. Freshly isolated adult rat hepatocytes were added to the CHO cell culture prelabeled with [3H]thymidine. After allowing the hepatocytes to attach on or near the CHO cells, aflatoxin B1 or benzo[a]‐pyrene was added to the culture and incubated for the desired time. DNA single‐strand breaks in CHO cells were measured by the alkaline elution technique. Aflatoxin B1 induced some DNA single‐strand breaks in CHO cells cultured alone, but in coculture system with hepatocytes the number of DNA single‐strand breaks increased greatly. The magnitude of the increase was related to the dose and the time of exposure to aflatoxin B1. Addition of proteinase‐K to the cell lysates increased the elution of DNA compared to that of samples without proteinase‐K. Benzo[a]pyrene did not induce any DNA single‐strand breaks in CHO cells in the absence of liver cells, but a significant number of single‐strand breaks were detected in the coculture system.

ISSN:0098-4108    

DOI:10.1080/15287398409530487

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The effect of phenobarbital (PB) pretreatment on the metabolism, covalent binding, and cytotoxicity of [14C]aflatoxin B1(AFB1) was studied in primary hepatocyte cultures. Hepatocytes from control and PB‐pretreated rats were isolated from perfused liver biopsies and cultured in a chemically defined, hormone‐supplemented medium. [14C]AFB1, dissolved in medium, was added to cultures at 20–22 h. The metabolism of AFB1 to water‐soluble products and its binding to trichloroacetic acid‐precipitable macromolecules were assessed 0.5 to 24 h later. At 6 h, PB pretreatment reduced total binding to macromolecules by 31% and reduced binding to RNA and DNA by 61% and 66%, respectively. In addition, PB protected cultures from the cytotoxic effects of AFB1, as evidenced by a significantly reduced (p <0.05) leakage of lactate dehydrogenase into the medium at 51 h. Elevated mixed‐function oxidase and giutathione S‐transferase activities, as well as higher levels of AFB1‐giutathione conjugate were measured in cultures from rats pretreated with PB. The protective action of PB was concluded to be due to the induction of hepatic giutathione S‐transferases responsible for the detoxification of A FB1.

ISSN:0098-4108    

DOI:10.1080/15287398409530488

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

BIOLOGICAL ASPECTS OF METALS AND METAL‐RELATED DISEASES. Edited by B. Sarkar, Raven Press, New York, 1983, 318 pp. $52.00.

ISSN:0098-4108    

DOI:10.1080/15287398409530489

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

ISSN:0098-4108    

DOI:10.1080/15287398409530476

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor