Accession Number : ADA116751

Title :   Mechanisms of Oxygen Toxicity at the Cellular Level.

Descriptive Note : Final rept. 1 Jan 68-31 Sep 81,

Corporate Author : MISSOURI UNIV-COLUMBIA JOHN M DALTON RESEARCH CENTER

Personal Author(s) : Brown,Olen R

PDF Url : ADA116751

Report Date : 30 Jun 1982

Pagination or Media Count : 32

Abstract : Studies using vitamins, precursors, and intermediates with analysis of carbohydrate, amino acid, lipid, protein, RNA and DNA synthesis and of enzyme activities in suspected pathways support the following events during oxygen intoxication of Escherichia coli. Biosynthesis of several amino acids are inhibited. Within less than 5 minutes valine is limiting for protein synthesis (subsequently 9 other amino acids become limiting). The resultant unloaded tRNA's stimulate the 'stringent response' (production of the powerful inhibitor guanosine tetraphosphate) which completely stops biosynthesis. Some of these sites (including quinolinate phosphoribosyl transferase, required for NAD synthesis) should be relevant to man. The data suggest that the vitamins thiamin pyrophosphate and niacin should be tested as potential protective agents against the toxicity in man of oxygen and of chemicals which produce cellular oxidative stress.

Descriptors :   *Oxygen, *Toxicity, *Biosynthesis, *Hyperoxia, Cells(Biology), Hyperbaric conditions, Intoxication, Escherichia coli, Inhibition, Amino acids, Proteins, Enzymes, Vitamins, Fatty acids, Glucose

Subject Categories : Biochemistry
      Microbiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE