Myocardial catecholamine levels have not yet been determined in the transplanted human heart. We measured norepinephrine, epinephrine, and dopamine in endomyocardial biopsies from 19 short-term (organ age, 6.6±+6 months) and five long-term (organ age, 62±2 months) heart transplant patients. Results were compared with those from 10 normal control subjects. In 17 of 19 short-term heart transplant patients, myocardial catecholamines were undetectable, indicating values below 0.1 pg/,ug noncollagen protein, which was the detection threshold of our assay. In the remaining two patients, myocardial catecholamines (pg/pg noncollagen protein)were norepinephrine (1.4 and 3.2), epinephrine (0.8 and 1.9), and dopamine (0.9 and 2.3), respectively. In the five long-term heart transplant patients, myocardial catecholamines were not detected. Catecholamine concentrations in 10 healthy control subjects were norepinephrine (10.3 +2.9), epinephrine (0.36 ±0.51), and dopamine (0.52 ±0.40). Low myocardial norepinephrine levels (<20% of control values) with unexplained high levels of epinephrine and dopamine were found in single transplant patients. In most heart transplant patients, however, myocardial catecholamines were undetectable up to five years after transplantation, indicating that the adrenergic response of these hearts probably depends on variations in plasma catecholamines or cardiac 3-receptor density. (Circulation 1990;82:620-623) M cyocardial norepinephrine and epinephrine are depleted in all portions of short-term autotransplanted canine hearts.12 In longterm autotransplanted canine hearts about 50% of control norepinephrine and epinephrine are found.1'2 Dopamine content, however, is only modestly decreased in short-and long-term autotransplanted canine hearts.23 Corresponding data for the transplanted human heart do not yet exist. Therefore, we measured the myocardial norepinephrine, epinephrine, and dopamine content in endomyocardial biopsies of patients that had undergone heart transplantation less than 18 months or more than 5 years ago. The concentrations measured were compared with those in 10 healthy control hearts.
Methods
PatientsEndomyocardial biopsies were obtained from the right ventricular septum in 19 patients 1-18 months From the German