DOPA decarboxylase inhibition does not influence the diuretic and natriuretic response to exogenous alpha-atrial natriuretic peptide in man.

The role of dopamine synthesis in the renal actions of human alpha-atrial natriuretic peptide (alpha ANP) was investigated in six dehydrated volunteers using the DOPA decarboxylase inhibitor carbidopa. Each subject received oral placebo or carbidopa (100 mg) followed by an infusion of alpha ANP 10 pmol.kg-1.min-1 for 1 h. The responses to placebo alone and to carbidopa alone were investigated on separate occasions. alpha ANP produced a similar increase in plasma immunoreactive alpha ANP whether placebo or carbidopa pretreatment had been given. Urinary dopamine excretion was increased by alpha ANP. Carbidopa pretreatment substantially attenuated this increase without affecting the natriuretic or water-diuretic response to alpha ANP. Carbidopa also failed to alter the change in filtration fraction produced by alpha ANP. The results suggest that increased synthesis of intrarenal dopamine is not required for the renal effects of alpha ANP in man.

RCT Entities:   Population Interventions Outcomes