Immunohistochemical and biochemical evidence for a cardiovascular mineralocorticoid receptor
| Autor: | Etienne-Emile Baulieu, Jean-Pierre Bonvalet, Nicolette Farman, Marc Lombès, J M Gasc, M. E. Oblin |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
medicine.medical_specialty
Receptors Steroid Vascular smooth muscle Endothelium Physiology medicine.drug_class Heart Ventricles Biology Pulmonary Artery Muscle Smooth Vascular chemistry.chemical_compound Mineralocorticoid receptor Internal medicine medicine.artery medicine Animals Aldosterone Aorta Heat-Shock Proteins Myocardium Adrenalectomy Immunohistochemistry medicine.anatomical_structure Endocrinology Receptors Mineralocorticoid chemistry Mineralocorticoid Circulatory system Pulmonary artery Female Endothelium Vascular Rabbits Cardiology and Cardiovascular Medicine Blood vessel |
| Zdroj: | Circulation research. 71(3) |
| ISSN: | 0009-7330 |
| Popis: | The presence of mineralocorticoid receptors (MRs) and their physicochemical characteristics were investigated in the heart and blood vessels of rabbits. Immunohistochemical methods using the monoclonal anti-idiotypic antibody H10E, which interacts with the steroid binding domain of MRs, revealed the presence of immunoreactive material in the heart and large blood vessels. In the heart, a positive staining was observed in myocytes and endothelial cells of atria and ventricles. In vessels, MRs were detected in the aorta and pulmonary artery. They were localized in endothelial and vascular smooth muscle cells. No staining was present in the small vascular bed, arterioles, and capillaries. In all these studies, the mineralocorticoid specificity of the staining was assessed by in situ competition experiments with aldosterone and RU486, a glucocorticoid antagonist. The presence of MRs in the heart and vessels was further demonstrated by specific aldosterone binding to one class of high affinity binding sites in the cytosol of the adrenalectomized rabbit heart (Kd, 0.25 nM; maximum MR concentration, 15-20 fmol/mg protein), whose mineralocorticoid specificity has been clearly established by competition studies. Sedimentation gradient analyses revealed that the cardiovascular MR is an 8.5S hetero-oligomer that includes the heat shock protein 90. The physicochemical characteristics of the cardiovascular MRs are virtually identical to those of the renal MRs. Altogether, our results clearly demonstrate the presence of MRs in the cardiovascular system. This supports the possibility of direct aldosterone actions in the heart and blood vessels. |
| Databáze: | OpenAIRE |
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