Histological Effect of Different Inhalants on the Heart and Lungs of Wistar Rats

Most inhalation methods of animal sacrifice target the respiratory and circulatory systems. Chances are that chemical inhalation methods of animal euthanasia for studies involving the heart and lungs may interfere with the outcome of the research. This study was done to evaluate the effect of the inhalation of chloroform, diethyl ether and formalin as methods of animal sacrifice on the cytoarchitecture of the heart and lungs of Wistar rats. Twenty adult male rats were divided into 4 groups of 5 rats each and acclimatized for 2 weeks. After acclimatization, the rats were sacrificed by cervical dislocation (control), chloroform inhalation, diethyl ether inhalation and formalin inhalation for groups A, B, C and D respectively. The heart and lungs were removed from the rats and fixed in 10% formal saline for histological studies using the haematoxylin and eosin method. Results show that none of the chemical agents inhaled had adverse effects on the histology of the hearts of the rats. On the contrary, the chemicals inhaled showed adverse effects on the histology of the lungs, ranging from tissue and cellular necrosis, inflammation and cytoarchitectural distortion of lung tissues. We can therefore conclude that inhalation methods of sacrifice are not ideal when researching on the lungs but on the heart they can be used based on the findings of this research.