title: AROMATIC-INDUCED PREVENTION OF FETAL TOXICITY OF 7,12-DIMETHYLBENZ(ALPHA)ANTHRACENE.
abstract: Large doses of 7,12-dimethylbenz[a]anthracene (7,12-DMBA) caused the death of rats within 1 day. A small amount of any of 5 polynuclear aromatic hydrocarbons or of an aromatic amine given before the highly toxic dose of 7,12-DMBA resulted in survival for more than 2 months and the specific atrophy of testis which follows 7,12-DMBA was largely prevented. Among the protective aromatics is 7,12-DMBA itself; a small dose of 7,12-DMBA given in advance induced protection of life against an otherwise lethal dose of 7,12-DMBA but only in a proportion of the animals, and testis was not protected from injury. The highly efficient inducers of protection were condensed aromatics composed of 4 or 5 rings. Protection of life against toxicity of big doses of 7,12-DMBA by pretreatment with small doses of aromatics required time (ca. 5 to 8 hours) for its induction. Ethionine given a few minutes after a highly efficient inducer of protection, 3-methylcholanthrene (3-MC), abolished induction of protection; ethionine given 8 hours after 3-MC exerted no influence on its protective effect. A lethal dose of 7,12-DMBA resulted in a considerable reduction in incorporation of tritium in DNA from tritiated thymidine while at the same time synthesis of menadione reductase was induced in liver. A small dose of 3-MC given prior to 7,12-DMBA was advantageous in partially protecting DNA synthesis.
mesh_terms: D000375:Aging; D000818:Animals; D000873:Anthracenes; D001551:Benz(a)Anthracenes; D004247:DNA; D006801:Humans; D006838:Hydrocarbons; D008099:Liver / Q000201:enzymology*; D008297:Male; D008660:Metabolism; D008748:Methylcholanthrene; D010088:Oxidoreductases; D051381:Rats; D012106:Research; D013737:Testis; D013936:Thymidine; D014116:Toxicology; D014316:Tritium; D014812:Vitamin K
chemical_list: D000873:Anthracenes; D001551:Benz(a)Anthracenes; D006838:Hydrocarbons; D014316:Tritium; D014812:Vitamin K; D008748:Methylcholanthrene; D004247:DNA; C030935:benz(a)anthracene; D010088:Oxidoreductases; C034020:anthracene; D013936:Thymidine
keywords: AGING; BENZANTHRACENES; DNA; EXPERIMENTAL LAB STUDY; HYDROCARBONS; LIVER ENZYMOLOGY; METABOLISM; METHYLCHOLANTHRENE; OXIDOREDUCTASES; RATS; TESTIS; THYMIDINE; TOXICOLOGIC REPORT; TRITIUM; VITAMIN K