HISTOPATHOLOGICAL CHANGES IN THE STOMACH TISSUE OF RATS FED WITH MUSSELS (Mytilus galloprovincialis)

Abstract

Dardanelles is exposed to environmental pollution for many years. The strait is important in terms of fish migration and shellfish farming. Fish and shellfish obtained from the strait is frequently consumed by local people. Mussels serve as useful indicators of temporal trends in environmental quality because they accumulate some contaminants in their tissues at levels many time higher than in the surrrounding water and quickly to changes in contamination. Although there are few data about the toxicity of seafood that is exposed to environmental pollution, there are no animal studies about the gastric toxicity of mussels grown in the Dardanelles. Our previous studies demonstrated that the water and mollusc from certain regions of the Dardanelles contained heavy metal salts. The purpose of the study is to demonstrate the histopathologic changes in the gastric tissues of rats which are fed with mussels that are collected from the Çamburnu region of the Dardanelles. Four groups of rats are included in the study, group 1 (n=6), control group fed with standard rat food, group 2 (n=6), 75%  mussels and 25% standard rat food daily, group 3 (n=6), 75% mussels and 25% standard rat food every two days, group 4 (n=6), 75%  mussels and 25% standard rat food every three days. After the routine histopathologic processing all gastric tissue samples are evaluated in terms of 8-hydroxy-2' -deoxyguanosine (8-OHdG) immunoreactivity with light microscopy and image analysis software. No histopathologic differences found in standard hematoxylin-eosin (H.E.) stained gastric tissue samples of the control group. In the second and third groups, a small amount of mononuclear cell infiltration was detected. In the fourth group, no significant difference was observed in mononuclear cells. In immunohistochemical staining, 8-OHdG immunoreactivity in gastric epithelial cells. 8-OHdG immunoreactivity was negative in gastric tissues in all groups.  There was no statistically significant difference between the groups that were fed every day, every other day and every three days with clam (p>0.05).