1,2-DIMETHYLHYDRAZINE-INDUCED PREMALIGNANT ALTERATIONS IN THE S-ADENOSYLMETHIONINE S-ADENOSYLHOMOCYSTEINE RATIO AND MEMBRANE LIPID LATERAL DIFFUSION OF THE RAT DISTAL COLON
1,2-DIMETHYLHYDRAZINE-INDUCED PREMALIGNANT ALTERATIONS IN THE S-ADENOSYLMETHIONINE S-ADENOSYLHOMOCYSTEINE RATIO AND MEMBRANE LIPID LATERAL DIFFUSION OF THE RAT DISTAL COLON
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DOI：
10.1016/0005-2736(88)90322-7
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发表时间：
1988-09-15
期刊：
影响因子：
--
通讯作者：
BRASITUS, TA
中科院分区：
文献类型：
--
作者：
HALLINE, AG;DUDEJA, PK;BRASITUS, TA
Prior studies by our laboratory, utilizing the 1,2-dimethylhydrazine experimental model of colonic cancer, had shown that administration of this procarcinogen for 5 weeks was found to increase phospholipid methyltransferase activity and the fluidity of rat distal colonic brush-border membranes. The present studies were conducted to further explore these ''premalignant'' colonic phenomena. Male albino rats of the Sherman strain were subcutaneously injected with dimethylhydrazine (20 mg/kg body weight per week) or diluent for 5 weeks. Animals from each group were killed, distal colonic tissue harvested and the levels of S-adenosylmethionine, S-adenosylhomocysteine and decarboxylated S-adenosylmethionine measured by high performance liquid chromatography. The activity of methionine adenosyltransferase was also examined in these tissues. Additionally, brush-border membranes were isolated from the distal colonocytes of control and treated-animals and examined and compared with respect to their phospholipid methylation activities as well as their lipid fluidity as assessed by the rotational mobilities of the probes 1,6-diphenyl-1,3,5-hexatriene and DL-12-(9-anthroyl)stearic acid and translational mobility of the fluorophore pyrenedecanoic acid. The results of these studies demonstrated: (1) phospholipid methyltransferase activity in rat colonic plasma membranes was increased concomitantly with increases in the cellular levels of S-adenosylmethionine and the S-adenosylmethionine/S-adenosylhomocysteine ratio in the distal colonic segment of treated-animals; and (2) the lateral diffusion of rat distal colonic brush-border membrane lipids, as assessed by the ratio of excimer/monomer fluorescence intensities of the fluorophore pyrenedecanoate, was also increased after dimethylhydrazine administration to these animals for 5 weeks.
