The influence of three commercial molluscicide pellets, Cloethocarb, Mesurol, and Spiess Urania 2000, on the activities of six enzymes in the hepatopancreas of Deroceras reticulatum were investigated by light and electron microscope histochemisty as well as by photometric studies. In the digestive cells, enzymes catalyzing energy-producing digestive processes (non-specific esterases and acid phosphatases) are induced, while, in the crypt cells, enzymes related to energy-consuming metabolic pathways often involved in detoxification (alkaline phosphatase, and NADPH-neotetrazoliumreductase) are activated
