[The effect of pesticides-CDM and AMZ on inhibition of the binding of 3H-clonidine to alpha 2-adrenoreceptor in rat forebrain tissue].

Chlordimeform (CDM) and Amitraz (AMZ) are two formamidine pesticides. CDM and AMZ inhibited the binding of 3H-Clonidine, 3H-Yohimbine to Alpha 2-adrenoreceptor of rat forebrain tissue in vitro with IC50 values of 62-68 mumol/L (CDM) and 95-110 mumol/L (AMZ). In vivo the administration of CDM and AMZ by ip showed the effect of inhibition on the binding and significant correlation of dose-effect r = 0.995 (CDM), 0.884 (AMZ). Time course test indicated that the lasting inhibition effect of CDM following exposure was shorter than AMZ. Similar results were observed with plasma in vitro. Comparing inhibition effects on rat forebrain tissue, directly induced by CDM and AMZ at different doses, with the results from the plasma of treated rats in vitro, there was a significant correlation r = 0.973 (CDM), 0.909 (AMZ). It showed that the inhibition effect of both CDM and AMZ was linked to the concentration of compounds chemical and their metabolites in blood. Time course and washing test indicated that the inhibition effect by CDM and AMZ was reversible.