The interaction between phosphorothionate insecticides, pneumotoxic trialkyl phosphorothiolates and effects on lung 7-ethoxycoumarin O-deethylase activity
Autor: | Aldridge Wn, Verschoyle Rd |
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Rok vydání: | 1987 |
Předmět: |
medicine.medical_specialty
Oxygenase Insecticides Time Factors Health Toxicology and Mutagenesis Oxidative phosphorylation 7-Alkoxycoumarin O-Dealkylase Toxicology Fenitrothion chemistry.chemical_compound Internal medicine Microsomes medicine Animals Lung biology Chemistry Respiratory disease Organothiophosphates Organothiophosphorus Compounds Rats Inbred Strains General Medicine Organ Size medicine.disease Enzyme assay Rats medicine.anatomical_structure Endocrinology Biochemistry Toxicity biology.protein Microsome Oxygenases Female |
Zdroj: | Archives of toxicology. 60(4) |
ISSN: | 0340-5761 |
Popis: | A number of phosphorothionate (P = S) insecticides, including bromophos and fenitrothion, prevent trialkyl phosphorothiolate (P = O)-induced lung toxicity and the resulting increase in lung weight normally observed at 3 days in the rat. Measurement of 7-ethoxycoumarin O-deethylase (7-EC) activity after both phosphorothionate and phosphorothiolate dosing revealed differing patterns of loss of enzyme activity. Depletion of 7-EC activity by phosphorothionates was maximal between 2 and 10 h after dosing, with recovery between 24 and 72 h. Phosphorothiolates, however, appear to cause two phases of loss of 7-EC activity, an initial fall of approximately 30% observed at 2 h and a secondary fall, maximal on day 3, with loss of 97% of activity, apparently associated with the pathological changes in the lung. It is suggested that oxidative metabolism of phosphorothionates known to occur at the P = S moiety, with suicidal loss of P-450, may then prevent oxidative activation of an S-methyl on the phosphorothiolates, the most likely site for production of a reactive intermediate capable of damaging the lung. Lung 7-EC in rat is sensitive to concentrations of the phosphorothionates bromophos and fenitrothion at 5-25 times less than those causing loss of liver 7-EC activity and at doses 125-600 times less than their LD50s. If repeated in man this may have implications for personnel occupationally exposed to these compounds. |
Databáze: | OpenAIRE |
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