白地霉长期饲喂大鼠对食管和前胃影响的组织形态观察

在肿瘤病因研究中,霉菌与肿瘤发生的关系,近十多年来愈来愈受到人们的重视,目前已知约有10种真菌的毒素有致癌作用,能诱发出大、小鼠不同器官的肿瘤,如黄曲霉毒素与肝癌的关系为人们所共知(徐达道1973;孟昭赫,1973;严瑞琪,1978;Lancaster,1961;Schoental,1961)。自国内有关白地霉(Geotrichum candidum Link)致瘤与促癌作用实验研究等文章发表以来(杨简、高进,1980),引起了工、农、医有关部门极大的关注。早在1958年上海即利用废泔脚水做原料,发酵培养白地霉制咸蛋白质的补充食料“人造肉精”,初步试用饲养猪、鸡作为蛋白质饲料,更进而利用白地霉菌体提取核酸及

HISTO-PATHOLOGICAL OBSERVATIONS OF THE RAT ESOPHAGUS AND FORESTOMACH AFTER LONG-TERM FEEDING OF GEOTRICHUM CANDIDUM LINK

A total of 248 Wistar rats were divided into 9 groups, i.e. 1 control group and 8 experimental ones. The control group consisted of 33 rats fed with the normal rat chew without the fungus. The rats of experimental groups were fed 6 times weekly with experimental rat chew containing different amounts of fresh fungus (Geotrichum candidum), its powder, or culture fluid, which were obtained from different factories in Shanghai. The daily dosage was from 5 million up to 400 million spores per ml. in experimental groups 1-4 and 2 ml. am mints of fungus material contained in 4 grams of rat chew. In experimental groups 5-8 the concentration of fungus material were 20-25% of the rat chew. 170 rats survived the experiments and were killed for histological examination by the end of the second year.The only Msto-pathological change observed was that the proportion of animals with basal cell hyperplasia in either esophagus (91.3%) or forestomach (98.0%) was significantly increased in contrast to the controls (80%) for esophagus and 85.0% for forestomach. Other types of hyperplasia observed in both -experimental and control animals included simple hyperplasia, bud-like hyperplasia, papillary outgrowth, inverted papillary growth and hyperkeratosis, These types of hyperplasia were, generally speaking, randomly distributed with bud-like hyperplasis being the only exception. The number of animals with bud-like hyperplasia in forestomaehs was increased in the experimental animals (6.67%) in contrast to the esophagus of the experimental animals (1.33%) and the controls (5% for forestomach and 0% for esophagus).One animal in the third experimental group showed early exophytic papilloma. However, there was in controls also one case which had papillary outgrowth resembling the tumour-like structure. So, only hyperplastic lesions were observed in the rats after a long-term feeding of the fungus so far as the esophagus and forestomach were concerned, and there appeared to be n o obvious malignant lesions.