Effect of Cadmium Chloride Administration and Restraint Stress Model on Cardiac Function of Female Wistar Rats

Abstract

Psychological stress which is becoming an epidemic due to continental economic meltdown, wars, climate change, disasters has reached a point of global health concern and can be mimicked in rats by restraint stress model. Cadmium chloride is a heavy metal salt whose exposure can be through inhalation, drinking contaminated water, sheltering and watering. This study therefore evaluated the combined effects of restraint stress and cadmium chloride on cardiac function of female Wistar rats. Twenty four female Wistar rats were randomly divided into four groups of six rats each. Control (CTL) group received only water and animal feed ad libitum. Restraint stress (RSS) group was restrained using wire mesh for 30 minutes each day for 21 days. Cadmium chloride (CDC) group received 100mg/kg b.w of Cadmium chloride orally and daily for 21 days. Restraint stress and Cadmium chloride group (RSC) was restrained for 30 minutes and received Cadmium chloride (100mg/kg) daily for 21days. Twenty four hours after the last procedures, the ECG of the rats was taken and then all rats were anesthetized and their blood collected for biochemical assay. Their hearts were also removed for histology studies. The result showed that restraint stress and cadmium chloride caused an altered electrical conductivity of the heart independently and their combination caused an exacerbated effect. The serum troponin I (cTnI), Lactate dehydrogenase (LDH), Creatine kinase (CK) were significantly (p<0.05) higher in RSS and CDC groups when compared with the control however the LDH level was significantly higher in the RSC group when compared with other groups. Histology of the hearts of the rats indicated that both restraint stress and cadmium chloride caused necrosis in the hearts of the rats. In conclusion, the combined exposures to cadmium chloride administration and restraint stress have exacerbated deleterious effects on cardiac function of female Wistar rats.