Histopathological and biochemical changes in the liver, kidney, and bloodof amphibians intoxicated with cadmium

Abstract

The worldwide decline in amphibian populations has made heavy metal pollution a subject of interest. The aim of this work was to analyze the effect of sublethal doses of cadmium (Cd) on the liver, kidney, and blood of Rhinella arenarum specimens. Serum markers indicative of hepatic injury (gamma glutamyltransferase, alkaline phosphatase, pseudo cholinesterase, and total cholesterol) and markers of renal dysfunction (blood urea nitrogen, serum creatinine, calcium, and glucose) showed variation in animals treated with a 0.5 mg/kg dose compared to controls. Histopathological images revealed alterations in the liver (hepatocyte ballooning and hyperplasia of Kupffer cells) and kidney (renal tubular lumen dilation with tubular necrosis) of animals with abnormal serum markers. The above-mentioned lesions were more evident with the 5 mg/kg dose. With the 0.5 mg/kg dose, hematological values remained normal with the exception of the leukocyte formula. Animals treated with 5 mg/kg showed a significant decrease in both white and red blood cell counts and hematocrit and hemoglobin values. Differential leukocyte counts showed neutrophilia, monocytosis, and lymphopenia. Morphological aberrations were found in white and red blood cells. Results indicated that the evaluation of morphological and functional parameters in kidney, liver, and blood is required in order to monitor amphibian populations exposed to chemical contaminants.