Biomedical subjects
Publications and source records attributed to E FORD.
Compared with other species, the rat is unusually vulnerable to polynuclear aromatic hydrocarbons. In the rat, relatively small amounts of carcinogenic aromatics (i) profoundly depress incorporation of thymidine in DNA, (ii) greatly induce menadione reductase in liver, and (iii) then kill the rat.
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.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.