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Decreased gene expression of KACh and KATP channels in hyperthyroid rabbit atria
Feng Zhang1, Guang Hai Zhou1, Qi An2
1School of Basic Medical Sciences, The Second Affiliated Hospital of Shandong First Medical University & Shandong Academy of Medical Science Jinan 250117, Shandong, China.
Insights
Hyperthyroidism-induced cardiac hypertrophy in rabbits led to decreased gene expression of ligand-gated potassium channels (KACh and KATP) in the atria, potentially linking to atrial fibrillation.
Area of Science:
- Cardiovascular Physiology
- Molecular Cardiology
- Endocrinology
Background:
- Cardiac hypertrophy is a significant structural abnormality linked to heart failure.
- Hyperthyroidism is a known inducer of cardiac hypertrophy.
- Ligand-gated potassium channels, including KACh and KATP, play roles in cardiovascular function, but their expression in hyperthyroid states is not well understood.
Purpose of the Study:
- To investigate the gene expression of KACh and KATP channels in the atria of rabbits with experimentally induced hyperthyroidism and cardiac hypertrophy.
- To explore the potential relationship between altered potassium channel gene expression and hyperthyroidism-induced cardiac changes.
Main Methods:
- Establishment of a hyperthyroidism-induced cardiac hypertrophy animal model in rabbits using thyroxine (T4) injection.
- Histopathological examination using Hematoxylin and Eosin (H&E) staining.
- Quantitative assessment of gene expression using Reverse Transcription Polymerase Chain Reaction (RT-PCR).
Main Results:
- T4 treatment significantly increased heart weight, heart rate, and systolic blood pressure in rabbits.
- A notable decrease in the gene expression of KACh and KATP channels was observed in the atria of hyperthyroid rabbits.
- Histomorphological analysis indicated cardiac hypertrophy in the T4-treated group.
Conclusions:
- The study demonstrates that hyperthyroidism induces cardiac hypertrophy in rabbits, accompanied by decreased atrial expression of KACh and KATP genes.
- These findings suggest a potential association between reduced KACh and KATP gene expression and the development of hyperthyroidism-related cardiac hypertrophy and atrial fibrillation.
Abstract:
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 KACh and metabolism sensor KATP channel. It is unclear whether the gene expression of KACh and KATP was altered in hyperthyroid rabbit atria. We aimed to investigate the expression of KACh and KATP 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 KACh and KATP genes was decreased in the atria of hyperthyroidism-induced cardiac hypertrophied rabbits. These findings indicated that the decreased gene expression of KACh and KATP may be related to hyperthyroidism-induced cardiac hypertrophy and atrial fibrillation.
