抄録
Purpose : We designed this study to investigate the mechanism of reduced cardiac β-adrenoceptor function that is associated with aging.
Materials and Methods : We assessed the density and affinity of β-adrenoceptors by (-) - [125I] iodocyanopindolol binding in the right atrial appendages obtained from 40 patients of varying age (range : 2 to 56 years) undergoing open-heart surgery. The mean right atrial pressure and cardiothoracic ratio were measured in all of the patients.
Results : There was a significant negative correlation between human right atrial β-adrenoceptor density and patient age (r = 0.575, p <0.001). Neither preoperative mean right atrial pressure nor preoperative cardiothoracic ratio was correlated with β-adrenoceptor density. The affinity of β-adrenoceptors did not correlate with patient age.
Conclusions : The decrease in human cardiac β-adrenoceptor function associated with increasing age is due, in part, to the reduced cardiac β-adrenoceptor density.
