Depletion of endogenous dopamine stores and shift in beta-adrenoceptor subtypes in cardiac tissue following five weeks of chronic denervation

• Published in: Molecular and cellular biochemistry 1998-06, Vol.183 (1-2), p.215-219
• Main Authors: Van der Vusse, G J, Dubelaar, M L, Coumans, W A, Steinfath, M, Smith, C C, Drake-Holland, A J, Noble, M I
• Format: Article
• Language: English
• Subjects: Animals; Dogs; Dopamine - metabolism; Epinephrine - analysis; Female; Heart Ventricles - innervation; Heart Ventricles - metabolism; Male; Muscle Denervation; Myocardium - chemistry; Myocardium - metabolism; Norepinephrine - analysis; Receptors, Adrenergic, beta-1 - analysis; Receptors, Adrenergic, beta-1 - metabolism; Receptors, Adrenergic, beta-2 - analysis; Receptors, Adrenergic, beta-2 - metabolism; Time Factors
• ISSN: 0300-8177
• DOI: 10.1023/A:1006861112530

Surgical ablation of extrinsic cardiac nerve fibers results in a chronically denervated state of the left ventricle of the heart. The present study was performed to elucidate the effect of a period of 5 weeks of chronic denervation on cardiac catecholamine levels in general and dopamine in particular. Moreover, the possible effect on cardiac beta-adrenoceptor subtypes was investigated. Experiments were performed on adult dogs. In addition to adrenaline and noradrenaline the tissue levels of dopamine were found to be severely depressed. A significant shift from beta1- to beta2-adrenoceptor subtype was observed, while the total beta-adrenoceptor density remained unaffected. The present findings indicate that catecholamine synthesis in chronically denervated hearts is impaired upstream of dopamine and that a shift in beta-adrenoceptor subtype occurs already within a relatively short period of five weeks of denervation, and suggest that the lack of endogenous catecholamines influence the relative expression levels of the two subtypes of beta-adrenoceptors present in cardiac tissue.