Effects of estrogen via estrogen receptors on parvalbumin levels in cardiac myocytes of ovariectomized rats
| Autor: | Wimon Wirakiat, Wandee Udomuksorn, Uraporn Vongvatcharanon, Surapong Vongvatcharanon |
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| Rok vydání: | 2012 |
| Předmět: |
medicine.medical_specialty
Histology medicine.drug_class Ovariectomy Diastole Estrogen receptor Internal medicine medicine Animals Myocyte Myocytes Cardiac Rats Wistar Dose-Response Relationship Drug biology Chemistry Estrogens Cell Biology General Medicine medicine.disease Immunohistochemistry Rats Menopause Parvalbumins Endocrinology Receptors Estrogen Estrogen Ovariectomized rat biology.protein Female hormones hormone substitutes and hormone antagonists Parvalbumin |
| Zdroj: | Acta Histochemica. 114:46-54 |
| ISSN: | 0065-1281 |
| DOI: | 10.1016/j.acthis.2011.02.004 |
| Popis: | The study investigated the effects of estrogen on parvalbumin (PV) levels in cardiac myocytes of ovariectomized rats, which is a model system for postmenopausal woman. Parvalbumin acts as a relaxing factor in cardiac myocytes. Adult female Wistar rats, 12 weeks old, were randomly divided into 5 groups of 10: sham-operated (SHAM), ovariectomized (OVX), and OVX receiving estrogen replacement of 10 μg/kg (Es10), 20 μg/kg (Es20) and 40 μg/kg (Es40). After 10 weeks, serum estrogen levels were measured and the α and β estrogen receptors in cardiac myocytes were investigated by immunohistochemistry. PV levels were examined by immunohistochemistry and Western blot analysis. Cardiac myocytes of all animals showed strong staining intensities for α immunoreactive (Es α-ir), but weak staining for β immunoreactive (Es β-ir) estrogen receptors. The Es α-ir was reduced in the cardiac myocytes of the OVX groups, but increased in the Es10, Es20 and Es40 groups. We therefore suggest that estrogen effects are mediated via Es α receptors rather than Es β receptors in female rat hearts. Estrogen and PV immunoreactive (PV-ir) levels and the intensity of the PV band observed in the OVX group were less than those of the SHAM group. In the Es10, Es20 and Es40 groups, the increased intensity of the PV-ir and PV bands correlated with the increased estrogen levels. The low PV levels in cardiac myocytes induced by low estrogen were restored by estrogen replacement therapy. Therefore a reduction of PV may lead to diastolic dysfunction in menopause. |
| Databáze: | OpenAIRE |
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