Variation in the response of plasma enzyme activities in avian species dosed with carbophenothion

The response of various species of Anser and Branta geese and other avian species to the ingestion of carbophenothion (S-[[(4-chlorophenyl)thio]methyl] O,O-diethyl phosphorodithioate) has been investigated. Optimum assay conditions for measurement of glutamate oxaloacetate transaminase, glutamate dehydrogenase, sorbitol dehydrogenase, and cholinesterase in avian plasma were developed for the study. The administration of acutely toxic doses of carbophenothion to Japanese quail, pigeons, and chickens, and to Greylag, Pink-footed, Greenland White-fronted, and Canada geese led to species-dependent responses for both plasma glutamate oxaloacetate transaminase and cholinesterase levels. Carbophenothion administered to Japanese quail at several dose levels produced changes in plasma enzyme levels which were dependent on dose and time. The level of plasma glutamate oxaloacetate transaminase after dosing in the Anser family of geese rose more rapidly than in the Branta species but no change was found in this enzyme in either chickens or pigeons. In contrast to geese and pigeons, chickens exhibited no plasma cholinesterase inhibition for 3 hr after dosing. These enzyme changes demonstrate a species variation in the toxicological response of birds to a pesticide and indicate the desirability of using more than one avian species for pesticide toxicity testing.