NEUROCHEMICAL ASSESSMENT OF ADRENERGIC RE INNERVATION OF THE TRANSPLANTED HUMAN HEART

Heart transplantation causes sympathetic cardiac denervation. Measurem ents of plasma concentrations of the main presynaptic noradrenaline me tabolite, dihydroxyphenylglycol (DOPEG, the plasma pool of which is ex clusively neuronal in origin), were used to examine sympathetic reinne rvation of the transplanted human heart. We determined arterial and co ronary-venous plasma concentrations of DOPEG in 27 heart transplant re cipients (transplant age ranging from 0.5 to 5 years) and in 9 control patients. In each of the control patients the DOPEG concentration was higher in coronary venous plasma than in arterial plasma (mean arteri o-venous increment: 57.3 +/- 8.7%; p < 0.001). However, in heart trans plant recipients, 18 out of 27 patients showed an arteriovenous increm ent in plasma DOPEG (mean increment in all patients 12.6 +/- 2.0 %; p < 0.05). The ratio of the coronary-venous to arterial DOPEG concentrat ion was positively correlated with the time after transplantation (p = 0.02 for individual results and p < 0.01 for mean group results). Thu s, our data provide evidence for a time-dependent partial sympathetic reinnervation of the transplanted heart.