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Steroidogenic enzyme gene expression in the human heart
K M Kayes-Wandover1, P C White
1Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas 75235-9063, USA.
The Journal of Clinical Endocrinology and Metabolism
|July 21, 2000
Summary
The human heart can produce corticosterone and deoxycorticosterone, but not cortisol or aldosterone. This suggests local roles for these steroids in cardiovascular function.
Area of Science:
- Cardiovascular Endocrinology
- Molecular Cardiology
Background:
- Corticosteroids influence cardiac function via mineralocorticoid (MR) and glucocorticoid (GR) receptors.
- Endogenous synthesis of aldosterone and corticosterone occurs in the rat heart.
Purpose of the Study:
- To investigate the potential synthesis of corticosteroids within the human cardiovascular system.
- To examine the expression of key steroidogenic enzymes and receptor genes in human heart tissues.
Main Methods:
- RT-PCR was employed to detect messenger ribonucleic acids (mRNAs) for steroidogenic enzymes (CYP11A, 3beta-HSD2, CYP21, CYP11B1, CYP11B2, CYP17) and receptors (GR, MR, 11-HSD2).
- Human cardiac samples included atria, ventricles, aorta, apex, septum, atrioventricular node, and whole adult/fetal hearts.
Main Results:
- Genes for steroidogenic enzymes and receptors were detected across most adult human heart samples.
- Ventricles lacked CYP11B1 expression; aorta and fetal heart showed CYP11B2, absent in adult hearts.
- Steroidogenic gene expression levels were significantly lower (approx. 0.1%) than in the adrenal gland.
Conclusions:
- Findings support autocrine or paracrine roles for corticosterone and deoxycorticosterone in the adult human heart.
- Evidence suggests cortisol and aldosterone are unlikely synthesized locally in the adult human heart.
- The study identifies potential local corticosteroid signaling pathways in cardiovascular tissues.