Decreased gene expression of K

Cardiac hypertrophy is a common myocardial structural abnormality which may cause heart failure. Many studies have shown that cardiac hypertrophy can be induced by hyperthyroidism. Ligand-gated potassium channels have been reported to be involved in various biological processes in the cardiovascular system, such as GPCR coupled K(ACh) and metabolism sensor K(ATP) channel. It is unclear whether the gene expression of K(ACh) and K(ATP) was altered in hyperthyroid rabbit atria. We aimed to investigate the expression of K(ACh) and K(ATP) genes in rabbit atria in our experimental model. We established an effective hyperthyroidism-induced cardiac hypertrophy animal model through an injection of T4. H&E staining and RT-PCR were used to observe the histomorphological damages and alteration of gene expression. The results showed that the heart weight, heart rate significantly increased in T4-treated rabbits. The systolic pressure increased from 115.60 mmHg to 152.6 mmHg in T4-treated rabbits. The expression of K(ACh) and K(ATP) genes was decreased in the atria of hyperthyroidism-induced cardiac hypertrophied rabbits. These findings indicated that the decreased gene expression of K(ACh) and K(ATP) may be related to hyperthyroidism-induced cardiac hypertrophy and atrial fibrillation.