Accession Number : ADA189550

Title :   Mechanism of Chemical Action and Treatment of Cyanide Poisoning.

Descriptive Note : Annual progress rept. 1 Sep 83-31 Aug 84,

Corporate Author : SRI INTERNATIONAL MENLO PARK CA

Personal Author(s) : Tyson, Charles A.

Report Date : 01 OCT 1984

Pagination or Media Count : 61

Abstract : In the second year under this contract, the combined hepatocyte/erythrocyte in vitro system developed in the first year was applied to the study of cyanide and antidotal mechanisms of action. Sodium nitrite and 4-dimethylaminophenol were found to reverse cyanide-induced depression of ATP levels in hepatocytes by catalyzing the formation of methemoglobin in erythrocytes coincubated with the hepatocytes. Cyanide complexed with the methemoglobin to form cyanmethemoglobin, which was quantitated directly in the erythrocytes; significant quantities of thiocyanate were not formed. Lowering the hemoglobin content in the medium below that required to complex the hemoglobin content in the medium below that required to complex the cyanide did not result in reversal of ATP depression. The relative effectiveness of the antidotes tested in a therapeutic protocol was estimated to be: 4-dimethylaminophenol > cobalt(II) chloride >> sodium thiosulfate > sodium nitrite.

Descriptors :   *ANTIDOTES, *CYANIDES, *POISONING, CELLS(BIOLOGY), CHEMICAL REACTIONS, ERYTHROCYTES, LIVER, MEDICAL SERVICES, METHEMOGLOBIN, QUANTITY, SODIUM NITRITE, THIOCYANATES, REACTION KINETICS.

Subject Categories : Toxicology
      Pharmacology

Distribution Statement : APPROVED FOR PUBLIC RELEASE