Cardiotoxic Assessment of Radiographic Developer Effluent in Wistar Rats

Aims: To demonstrate the histopathological changes in cardiac tissues of Wistar rats following exposure to developer effluent.

Study Design: A case control study.

Place and Duration of Study: Department of Radiography, Nnamdi Azikiwe University, Nnewi Campus, Anambra State, Nigeria.

Methodology: Eighteen young Wistar rats of weighing 140-220 g were used for the study. The animals were divided randomly into three groups of 6 rats each based on the dose of developer effluent administered to them – i.e. control group I (0 dose) and experimental groups II (lower dose, 200 mg/kg) and III (higher dose, 400 mg/kg) respectively. The groups were further classified as either A or B sub-groups of three rats each, depending on the duration (14 or 28 days) of effluent administration. The effluent administration was done by oral gavages. Image processing and analyses were done using ImageJ software (version 1.49) to obtain particle count, circularity of particles, number of nuclei and number of connective tissue spaces.

Results: Normal heart histology was observed in the control group. In contrast, lower dose of developer effluent administered for two weeks caused mild edema on cardiac tissues and occasional loss of myocardial fibers. Fourteen days of effluent administration at higher dose indicated alteration in the cardio-myocytes, necrosis of intercalated discs, moderate distortion and enlargement of cardio-myocytes structure and edema. Administration of lower dose developer effluent for 28 days caused severe distortion and enlargement of the cardio-myocytes structure with destruction and loss of intercalated disk. The higher dose of effluent caused severe distortion and enlargement of the cardio-myocytes, loss of intercalated discs, and irregular nuclei after 28 days of administration.

Conclusions: The present study which indicated adverse effects of acute/chronic and long-term/short-term exposures to sub-lethal doses of developer effluent on Wistar rats’ heart tissues suggests the need for proper management and disposal of developer effluent.