Histochemical studies of some enzymes in the tissues of the schistosome vector snail Bulinus truncatus (Audouin) with special reference to the effects of a molluscicide. I. Dehydrogenases.

The histochemistry of five dehydrogenases, namely isocitrate, succinate and lactate dehydrogenases and NADH and NADPH diaphorases were studied in the tissues of the schistosome vector snail, Bulinus truncatus, before and after treatment with the molluscicide Frescon. Isocitrate and succinate dehydrogenases showed their strongest activity in the respiratory epithelia, while lactate dehydrogenase showed a high level of activity in the tissues that are known to be capable of glycolysis. Following the administration of Frescon, a marked loss in the activity of isocitrate dehydrogenase and NADPH diaphorase occurred. It is postulated that the molluscicide toxin may interfere with cellular respiration, especially in the exposed areas of the body.