Chromosome aberrations in epithelial cells of the digestive tract of rats induced by 1-methyl-3-nitro-1-nitrosoguanidine.
The effect of a gastrointestinal carcinogen, 1-methyl-3-nitro-1-nitrosoguanidine (MNNG), on chromosomes of rat digestive tract epithelial cells was studied. A blind loop of colorectal segment was surgically produced and the epithelial cells of this loop were treated twice with 0.5% and 0.1% MNNG solutions, respectively (5 ml each). After the first treatment, the mucosa revealed severe damage, and repair and mitoses upon regeneration were maximal on days 4-6. Chromosomal aberrations were studied 3-48 hr after the second treatment. Cells with chromosomal aberrations increased progressively from 6 hr on, reaching their maximum level at 15 hr, and gradually returned to the original level at 48 hr. Chromosomal aberrations consisted of gaps, breaks, and exchanges. The above results indicate that gastrointestinal carcinogens induce chromosomal aberrations in target epithelial cells.
D000818:Animals; D002869:Chromosome Aberrations; D003106:Colon / Q000187:drug effects / Q000473:pathology*; D003110:Colonic Neoplasms / Q000139:chemically induced* / Q000235:genetics / Q000473:pathology; D007413:Intestinal Mucosa / Q000187:drug effects / Q000473:pathology*; D007621:Karyotyping; D008297:Male; D008677:Metaphase; D008769:Methylnitronitrosoguanidine / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains
D008769:Methylnitronitrosoguanidine