Impairment of methylamine clearance in uremic patients and its nephropathological implications.

The urinary levels of methylamine were analyzed by an HPLC/fluorometric method following derivatization of the amine with O-phthaldialdehyde (OPA). The excretion of methylamine in the uremic patients was found to be dramatically reduced. The impairment of clearance of methylamine explains why this amine was substantially increased in the serum of uremic patients. Increased deamination of methylamine would enhance formaldehyde and oxidative stresses, i.e. in the blood vessels, and cause vascular damage. This may be related to the increased risk of angiopathy associated with renal failure, and accelerate the progression of renal failure.