TOXICOLOGICAL EFFECTS OF BROMOBENZENE AND 2,2'-DICHLOROBIPHENYL ON THE POND SNAIL LYMNAEA-STAGNALIS - HISTOLOGICAL STRESS IN DIGESTIVE GLAND-CELLS

1. Snails were injected with 400 or 800 nmol of bromobenzene (BB) or with 1200 or 1800 nmol 2,2'-dichlorobiphenyl (2,2'-DCB); these doses were selected after lethality experiments. 2. Control snails were not injected, while injection-controls were injected with 5μl polyethyleneglycol, which was used as diluter (BB) or solvent (2,2'-DCB). 3. Snails were killed 24 hr after treatment, and digestive glands were processed for histological examinations (seven μm cross-sections). 4. 400 nmol BB and both doses of 2,2'-DCB caused a decrease of the epithelial height of the digestive cells, suggesting an inhibition of digestive cell function. 5. 400 nmol BB furthermore caused an increase of the mean cell section of the glycogen cells, suggesting that glycogen storage is affected. 6. The 800 nmol BB dose did not affect the parameters, and these results suggest that at higher (more lethal) doses cell metabolism is rapidly stopped, leaving the tissues seemingly in the control situation. 7. The effects of both chemicals are probably related to the action of reactive intermediates, which might be formed during metabolism of the compounds by the cytochrome P-450 containing mixed-function oxygenase system.