Carbaryl-induced Histopathologic Alterations in the Digestive Tract of the Levantine Frog, Pelophylax bedriagae (Anura: Ranidae)

Abstract

In this study, histopathologic changes following carbaryl exposure for 96 hr were investigated in the digestive tract of Levantine frog, Pelophylax bedriagae. Adult frogs were exposed to carbaryl once by oral gavage in concentrations of 0.05, 0.1, and 0.2 mg/g. Histopathological changes were more prominent in medium- (0.1 mg/g) and high-dose (0.2 mg/g) groups than in the low-dose (0.05 mg/g) group. Esophageal cells showed vacuolization, cellular swelling, nuclear pyknosis, karyolysis, and necrosis. Additionally, esophageal glandular atrophy and infiltration of inflammatory cells around esophageal glands were observed at medium and high doses. In the stomach, there were prominent histopathologic defects such as cellular swelling and necrosis in gastric glands, necrotic cells within the interstitial spaces, separation of epithelial cell layer, congested vessels, and hemorrhage at medium and high doses. In the intestine, detachment of epithelial layer, epithelial cell disorganization, inflammation, and necrosis were detected at medium and high doses. The results of this study showed that carbaryl caused adverse effects on the digestive tract of the Levantine frog, P. bedriagae.