Lack of preventive effect of 6-hydroxy-dopamine on a decrease of beta-adrenergic receptors induced by repeated stress in the heart of rats.

Immobilization stress (2.5 h daily) repeated daily for 7 days resulted in a significant decrease in the number of beta-adrenergic receptors in heart compared to control values. Administration of 6-hydroxy-dopamine failed to prevent the stress-induced reduction in the number of beta-adrenergic receptors in the heart of rats as compared to intact stressed rats. These results support the concept that beta-adrenergic receptors in the heart of rats are primarily under the control of the noradrenergic nervous system.