Mechanisms of intestinal absorption of the carcinogen MNNG (N-Methyl-N'-nitro-N-nitrosoguanidine)

Journal Article · Wed Jun 01 04:00:00 EDT 1988 · Proc. Soc. Exp. Biol. Med.; (United States)

DOI:https://doi.org/10.3181/00379727-188-42729· OSTI ID:6754559

Koyama, S Y; Hollander, D; Dadufalza, V

The authors studied the characteristics and mechanisms of MNNG (N-methyl-N'-nitro-N-nitrosoguanidine) intestinal absorption and the interaction between bile acids and fatty acids and MNNG absorption rat in vivo in male Sprague-Dawley rats. They found that MNNG was absorbed by simple passive diffusion. Transport of MNNG was the highest at pH 6.0. The addition of the bile salt, taurocholate by itself, greatly increased MNNG absorption, while the addition of the long-chain unsaturated fatty acids, oleic and linoleic, decreased the rate of absorption of MNNG. The phospholipid lecithin addition to the perfusate did not change the rate of MNNG absorption. Induction of dietary vitamin A deficiency (serum vitamin A level decreased from 40.9 to 13.7 ..mu..g/dl) did not change the absorption rate of MNNG. These studies demonstrate that bile acids, dietary fatty acids, and the pH of the intestinal content can modify the rate of absorption of this carcinogen by the small intestine. Since initial intestinal absorption determines serum levels and subsequent reabsorption and enterohepatic cycling determines long-term lumenal levels, serum levels, and total body content, factors which modify the rate of intestinal absorption of MNNG could also modify its carcinogenicity.

• Research Organization: Univ. of California, Irvine (USA)
• OSTI ID: 6754559
• Journal Information: Proc. Soc. Exp. Biol. Med.; (United States), Journal Name: Proc. Soc. Exp. Biol. Med.; (United States) Vol. 188:2; ISSN PSEBA
• Country of Publication: United States
• Language: English

Related Subjects

560300* -- Chemicals Metabolism & Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ABSORPTION
ANIMALS
BILE ACIDS
CARBONIC ACID DERIVATIVES
CARBOXYLIC ACIDS
CARCINOGENESIS
DIFFUSION
GUANIDINES
HYDROXY COMPOUNDS
INTESTINAL ABSORPTION
MAMMALS
NITROSO COMPOUNDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PATHOGENESIS
PH VALUE
RATS
RODENTS
STEROIDS
STEROLS
UPTAKE
VERTEBRATES