Effect of temperature on the inhibition of rat brain synaptosomal ATPases by DDT and its structural analogs
✍ Scribed by Sreeramulu C. Chetty; Charles N. Aldous; Durisala Desaiah
- Publisher
- John Wiley and Sons
- Year
- 1984
- Tongue
- English
- Weight
- 409 KB
- Volume
- 4
- Category
- Article
- ISSN
- 0260-437X
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✦ Synopsis
In vitro effects of DDT and its isomers or metabolites were studied on Na+-K+-ATPase and oligomycinsensitive ( 0 s ) Mg++-ATPase activities at 17, 27 and 37 O C in rat brain synaptosomes. Dicofol and methoxychlor were found to be more effective inhibitors of Na+-K+-ATPase and 0 s Mg++-ATPase than DDT, DDD and DDE. Inhibition of 0s Mg++-ATPase by the compounds tested (except DDE) was found to be greater at 17 "C than at higher temperatures (17 > 27 > 37 "C), suggesting a negative temperature correlation trend.
Na+-K+-ATPase was less sensitive to these compounds when compared with 0 s Mg++-ATPase and the inhibition was greater at higher temperatures (37 >27 > 17 "C), suggesting a positive temperature correlation trend. Other DDT isomers and metabolites showed variable effects on Na+-K+-ATPase and 0 s Mg++- ATPases. DDD, but not DDE, inhibited both enzyme activities and the inhibition was independent of temperature. No significant differences were observed in the inhibitory potencies of the various DDT, DDD or DDE ring substitutes studied. The present data indicate that DDT, dicofol and methoxychlor were more effective inhibitors of 0 s Mg++-ATPase than Na+-K+-ATPase and that the inhibition of the former enzyme had a negative temperature dependence, a feature which parallels toxicity results in insects.