Increasing of Caspase-1 mRNA in the Lung and Heart of Hyperthyroid Broiler Chickens

To clarify the effect of T3-induced hyperthyroidism on Caspase-1 mRNA expression in the lung and ventricles of the heart, semi quantitative reverse transcription-PCR was performed on total RNAs isolated from broiler chicken lung and heart after feeding supplementary T3 (1.5 mg T3 kg-1) for 2 weeks. The Caspase-1 genes were expressed in the lung and heart (right and left ventricles) of control and T3-treated broilers at 14th day of ages. The relative amount of Caspase-1 mRNA expression in the lung, right ventricle and left ventricle of heart was higher (p<0.05) in T3-treated broilers than in control broilers at 14th day of age. Among T3-treated groups, the relative amount of Caspase-1 mRNA expression in the lung was also significantly (p<0.05) higher than left and right ventricles of heart while the variations among control groups were not significant. In conclusion, Caspase-1 gene was constitutively expressed in the lung and heart of broiler chickens. It is probable that increased Caspase-1 gene expression in the lung and ventricles of heart are involved in the pathophysiology of cardiovascular function in broilers with hyperthyroidism. Further studies are required to find the pathways involved in the apoptosis.