Stimulatory effect of dexamethasone on angiotensin-converting enzyme in neonatal rat cardiac myocytes

Autor(es)

M.L.M. Barreto-Chaves ; A. Heimann ^[2] ; J.E. Krieger ^[3]

• Tipo de documento: Artigo Científico
• Fonte: Brazilian Journal of Medical and Biological Research; v. 33, n. 6, p. 661-664, 2000-06-00.

Resumo

Angiotensin-converting enzyme (ACE) plays a central role in cardiac remodeling associated with pathological conditions such as myocardial infarction. The existence of different cell types in the heart expressing components of the renin-angiotensin system makes it difficult to evaluate their relative role under physiological and pathological conditions. Since myocytes are the predominant cellular constituent of the heart by mass, in the present study we studied the effects of glucocorticoids on ACE activity using well-defined cultures of neonatal rat cardiac myocytes. Under steady-state conditions, ACE activity was present at very low levels, but after dexamethasone treatment ACE activity increased significantly (100 nmol/l after 24 h) in a time-dependent fashion. These results demonstrate the influence of dexamethasone on ACE activity in rat cardiac myocytes. This is consistent with the idea that ACE activation occurs under stress conditions, such as myocardial infarction, in which glucocorticoid levels may increase approximately 50-fold. (AU)

• Processo FAPESP: 96/08546-5 - Controle da expressão do gene da enzima conversora de angiotensina I (ECA) em fibroblastos cardíacos
• Beneficiário: Maria Luiza de Morais Barreto de Chaves
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado