Behavior of plasma free and conjugated noradrenaline - A comparison of patients with mild heart failure and patients with chronic hemodialysis

Plasma levels of free and conjugated noradrenaline and adrenaline were measured in normal control subjects (Group C), in patients with NYHA class I (Group I) and NYHA class II (Group II) cardiac disease, and in patients undergoing hemodialysis (Group R). The magnitude of plasma free noradrenaline levels was Group R = Group II > Group I = Group C. The order of plasma conjugated noradrenaline levels was Group R >> Group II > Group I = Group C. The magnitude of plasma free adrenaline levels was Group R > Group II = Group I = Group C. The relationship of plasma conjugated adrenaline levels was Group R > Group II > Group I = Group C. Plasma levels of conjugated noradrenaline and adrenaline were significantly higher in Group R than in Group II, although there was no difference in the plasma free noradrenaline and adrenaline levels. In patients undergoing chronic hemodialysis, significantly decreased plasma conjugated noradrenaline and adrenaline levels equivalent to the levels seen in Group II patients, were observed immediately after hemodialysis. These results suggest that plasma conjugated noradrenaline levels increase in patients with congestive heart failure due to increased sympathetic nerve activity and that plasma conjugated noradrenaline and adrenaline levels increase markedly in patients undergoing chronic hemodialysis, mainly due to decreased renal excretion.