Dopamine deficiency--its potential contribution to chronic renal failure complicating hypertension.

Baseline dihydroxyphenylalanine (DOPA) and dopamine (DA), their respective sulfates as well as oral DOPA administration-induced changes were compared in age- and blood pressure-matched hypertensive patients without and with moderate chronic renal failure (CRF) and control subjects. The only common feature of both hypertensive groups was a defective DA generation from DOPA. Hypertensive patients with moderate CRF were distinct from those without, having increased basal concentrations of plasma DOPA and DA sulfates. After oral DOPA administration, plasma and urinary DOPA sulfate rose while renal DA sulfate clearance was decreased. Possible enzymatic defects contributing to CRF-induced increases of DOPA and DA sulfates and their potential role in perpetuating renal failure via glomerular hypertension are discussed.