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Thyroid function disturbance and type 3 iodothyronine deiodinase induction after myocardial infarction in rats a time course study
- Source :
- Endocrinology. 148(10)
- Publication Year :
- 2007
-
Abstract
- In humans, there is a significant decrease in serum T(3) and increase in rT(3) at different time points after myocardial infarction, whereas serum TSH and T(4) remain unaltered. We report here a time course study of pituitary-thyroid function and thyroid hormone metabolism in rats subjected to myocardial infarction by left coronary ligation (INF). INF- and sham-operated animals were followed by serial deiodination assays and thyroid function tests, just before, and 1, 4, 8, and 12 wk after surgery. At 4 and 12 wk after INF, liver type 1 deiodinase activity was significantly lower, confirming tissue hypothyroidism. Type 3 deiodinase (D3) activity was robustly induced 1 wk after INF only in the infarcted myocardium. Reminiscent of the consumptive hypothyroidism observed in patients with large D3-expressing tumors, this induction of cardiac D3 activity was associated with a decrease in both serum T(4) ( approximately 50% decrease) and T(3) (37% decrease), despite compensatory stimulation of the thyroid. Thyroid stimulation was documented by both hyperthyrotropinemia and radioiodine uptake. Serum TSH increased by 4.3-fold in the first and 3.1-fold in the fourth weeks (P < 0.01), returning to the basal levels thereafter. Thyroid sodium/iodide-symporter function increased 1 wk after INF, accompanying the increased serum TSH. We conclude that the acute decrease in serum T(4) and T(3) after INF is due to increased thyroid hormone catabolism from ectopic D3 expression in the heart.
- Subjects :
- Male
endocrine system
medicine.medical_specialty
Time Factors
endocrine system diseases
Deiodinase
Myocardial Infarction
Radioimmunoassay
Thyroid Gland
Thyrotropin
Stimulation
Thyroid function tests
Iodide Peroxidase
Iodine Radioisotopes
Endocrinology
Internal medicine
Medicine
Animals
Myocardial infarction
Rats, Wistar
Thyrotropin-Releasing Hormone
medicine.diagnostic_test
biology
Symporters
business.industry
Myocardium
Thyroid
Heart
medicine.disease
Rats
Thyroxine
medicine.anatomical_structure
biology.protein
Triiodothyronine
Thyroid function
business
Endocrine gland
Subjects
Details
- ISSN :
- 00137227
- Volume :
- 148
- Issue :
- 10
- Database :
- OpenAIRE
- Journal :
- Endocrinology
- Accession number :
- edsair.doi.dedup.....9f2db4737df1ef8c977d78ab2e7c1869