Plasmatic renin activity in patients treated with L-dopa and inhibitor of dopa decarboxylase (IDC).

Plasmatic renin activity (PRA) was studied in patients receiving L-dopa, together with a decarboxylase inhibitor, at rest times and after periods of physical exertion. Although we can superimpose the results from unrelated Parkinson's disease patients on those of the control group, the results are inversed in stabilized patients (lowered PRA) and dyskinetic patients (increased PRA). There is a definite correlation between the increase in PRA and intensity of the dyskinesia. Dosage is the only other factor differentiating the two groups of Parkinsonians treated. The figures relative to arterial pressure are studied in the various groups.