Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 1 de 1
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Mech Ageing Dev ; 100(3): 277-97, 1998 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-9578116

RESUMO

The sinoatrial (SA) node is the cardiac pacemaker and changes in its adrenergic-muscarinic phenotype have been postulated as a determinant of age-associated modifications in heart rate variability. To address this question, right atria were microdissected, the SA node area was identified by acetylcholinesterase staining, and, using a RT-PCR method, the accumulation of mRNA molecules encoding beta1- and beta2-adrenergic (beta1- and beta2-AR) and muscarinic (M2-R) receptor was quantified to define the proportion between beta-AR and M2-R mRNAs within the sinoatrial area of adult (3 months) and senescent (24 months) individual rat hearts. In adult hearts, the highest M2-R/beta-AR mRNA ratio was observed within the sinoatrial area compared with adjacent atrial myocardium, while in the senescent hearts, no difference was observed between sinoatrial and adjacent areas. This change was specific of the sinoatrial area since adult and senescent whole atrial or ventricular myocardium did not differ in their M2-R/beta-AR mRNA ratio, and was associated with a fragmentation of acetylcholinesterase staining of the senescent SA node. Quantitative changes in the expression of genes encoding proteins involved in heart rate regulation specifically affect the sinoatrial area of the senescent heart.


Assuntos
Envelhecimento/metabolismo , Miocárdio/metabolismo , Receptores Adrenérgicos beta 1/genética , Receptores Adrenérgicos beta 2/genética , Receptores Muscarínicos/genética , Nó Sinoatrial/metabolismo , Animais , Coração/anatomia & histologia , Masculino , Reação em Cadeia da Polimerase , RNA Mensageiro , Ratos , Ratos Wistar , Receptor Muscarínico M2 , Sensibilidade e Especificidade , Nó Sinoatrial/anatomia & histologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...