Homma Y, Kondo Y, Kakizoe T, Aso Y, Nagase S
Department of Urology, Faculty of Medicine, University of Tokyo, Japan.
Food Chem Toxicol. 1991 Jun;29(6):373-6. doi: 10.1016/0278-6915(91)90076-j.
A previous 1-wk study measuring the agglutinability of bladder epithelial cells by concanavalin A had suggested a high susceptibility of analbuminaemic rats to bladder carcinogenesis by sodium saccharin (Honma et al., Cancer Letters 1983, 19, 7). A long-term study was conducted to confirm the results of this short-term assay. Sodium saccharin was administered at 5% in the diet to groups of 35 male analbuminaemic rats and 36 male rats of the Sprague-Dawley strain. No bladder carcinomas nor precancerous lesions were observed in any of the rats exposed to sodium saccharin. The discrepancy between the results of the agglutination assay and the long-term experiment might be attributable to a sharp increase in urine volume in analbuminaemic rats during the first week of treatment. The resultant distension of the bladder wall might make the epithelial cells more susceptible to concanavalin A agglutination. The results indicated no demonstrable bladder carcinogenicity of sodium saccharin in analbuminaemic rats and excluded the possibility that these particular mutant rats could be useful animals for shorter-duration screening for bladder carcinogens.
先前一项为期1周的研究通过伴刀豆球蛋白A来测定膀胱上皮细胞的凝集性，该研究表明无白蛋白血症大鼠对糖精钠诱导的膀胱癌发生高度易感（本间等人，《癌症通讯》1983年，第19卷，第7页）。开展了一项长期研究以证实这一短期试验的结果。将5%的糖精钠添加到饲料中，分别喂给35只雄性无白蛋白血症大鼠和36只斯普拉格-道利品系的雄性大鼠。在任何接触糖精钠的大鼠中均未观察到膀胱癌或癌前病变。凝集试验结果与长期实验结果之间的差异可能归因于在治疗的第一周无白蛋白血症大鼠的尿量急剧增加。膀胱壁的由此产生的扩张可能使上皮细胞对伴刀豆球蛋白A凝集更易感。结果表明糖精钠在无白蛋白血症大鼠中无明显的膀胱致癌性，并排除了这些特定的突变大鼠可作为用于较短时间膀胱致癌物筛查的有用动物的可能性。
