Related Experiment Videos
Aortic intimal thickening and myosin isoform expression in hyperthyroid rabbits
L Giuriato1, A C Borrione, A M Zanellato
1Institute of General Pathology, University of Padova, Italy.
Arteriosclerosis and Thrombosis : a Journal of Vascular Biology
|September 1, 1991
Summary
Thyroid hormones promote vascular smooth muscle cell (SMC) proliferation and migration, leading to aortic intimal thickening. This process involves changes in myosin isoform expression and precedes cell accumulation in the intima.
Area of Science:
- Cardiovascular Biology
- Endocrinology
- Cell Biology
Background:
- Thyroid hormones influence cellular processes.
- Vascular smooth muscle cells (SMCs) play a role in vascular health and disease.
- Intimal thickening is a key feature of several cardiovascular pathologies.
Purpose of the Study:
- To investigate the effect of thyroid hormones on vascular SMCs.
- To examine the role of thyroid hormones in aortic intimal thickening.
- To elucidate the molecular mechanisms underlying thyroid hormone-induced SMC changes.
Main Methods:
- Administered L-Thyroxine to rabbits and studied aortic SMCs over 26 days.
- Utilized monoclonal antibodies and immunocytochemical procedures for protein analysis.
- Assessed DNA synthesis using bromodeoxyuridine incorporation.
Main Results:
- Thyroxine administration induced aortic intimal thickening and SMC proliferation.
- Hyperthyroid SMCs exhibited changes in myosin isoform expression, shifting towards an 'immature' phenotype.
- SMC migration and proliferation preceded intimal thickening, with myosin isoform switch occurring earlier.
Conclusions:
- Thyroid hormones play a specific role in inducing medial SMC proliferation and migration into the intima.
- The observed switch in myosin isoform expression precedes SMC accumulation in the intima.
- Thyroid hormone-induced changes in SMCs contribute to the development of intimal thickening.