INHIBITORY EFFECT OF CHLORPROMAZINE ON NEMATODE EGGS AND LARVAE

Chlorpromazine inhibited the hatching of eggs of the parasitic nematod e Haemonchus contortus and the free-living nematode Caenorhabditis ele gans. In both species, hatching occurred st a concentration of 100 mu g/ml but was almost totally blocked at 400 mu g/ml. In the case of C. elegans, the effect was shown to be reversible by removal of chlorprom azine after exposure of the eggs to the drug for 1 hr. Caenorhabditis elegans larvae that hatched in a chlorpromazine concentration of 100 m u g/ml were killed, but those that hatched in a concentration of 6.25 mu g/ml were not. Taken together with data published by others, these observations indicate that the first-stage larva of C. elegans is less sensitive to chlorpromazine than is the adult worm.