Pyrethroid inhibition of basal and calmodulin stimulated Ca2+ ATPase and adenylate cyclase in rat brain.
Effects of two classes of pyrethroids, permethrin and resmethrin (type I), cypermethrin and deltamethrin (type II), on basal (calmodulin-deficient) and calmodulin stimulated activities of Ca2+ ATPase and adenylate cyclase from rat brain were studied in vitro. None of the pyrethroids inhibited synaptosomal basal Ca2+ ATPase, but permethrin and deltamethrin inhibited basal adenylate cyclase in the nuclear fraction of a brain homogenate. Both groups of pyrethroids decreased the calmodulin activated Ca2+ ATPase and adenylate cyclase from brain synaptosomes and nuclear fraction. The results indicate that calmodulin-stimulated Ca2+ ATPase is more sensitive to type II pyrethroids and pyrethroids are more effective on calmodulin stimulated enzymes than basal enzyme activities. Since calmodulin, adenylate cyclase and Ca2+ ATPase are known to participate in various brain processes, it is possible that pyrethroids alter neural transmission, however, additional in vivo work would be needed to confirm this possibility.
D000067956:Adenylyl Cyclase Inhibitors; D000818:Animals; D001921:Brain / Q000201:enzymology*; D000252:Calcium-Transporting ATPases / Q000037:antagonists & inhibitors*; D002147:Calmodulin / Q000502:physiology*; D002467:Cell Nucleus / Q000201:enzymology; D066298:In Vitro Techniques; D007306:Insecticides / Q000494:pharmacology*; D008297:Male; D011722:Pyrethrins / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013574:Synaptosomes / Q000201:enzymology
D000067956:Adenylyl Cyclase Inhibitors; D002147:Calmodulin; D007306:Insecticides; D011722:Pyrethrins; D000252:Calcium-Transporting ATPases