Norepinephrine clearance, chromogranin A and dopamine beta hydroxylase in renal failure

Plasma norepinephrine (NE) levels are normal or elevated in patients with renal failure even though uremia often damages the sympathetic nerves that release NE. We infused 3H-NE into subjects with normal, mildly depressed, or absent renal function. 3H-NE clearance was depressed 20% in mild renal failure and 40% in patients on hemodialysis. The calculated rate of NE release into plasma was low in uremics even though their plasma NE was normal. Dopamine beta hydroxylase (D beta H) and chromogranin A are released from sympathetic nerve endings along with NE. D beta H levels were low in uremia and D beta H levels doubled following hemodialysis. Chromogranin A levels were very high in uremics and increased slightly following hemodialysis. Plasma clearance of both NE and chromogranin A appears low in renal failure. The calculated rate of NE release is diminished in uremics, which is in accord with reports of autonomic neuropathy in these patients.