EFFECT OF CYCLOSPORINE-A ON RENAL CORTICAL RESISTANCES MEASURED BY COLOR DOPPLER FLOWMETRY ON RENAL GRAFTS

Doppler spectra were recorded at different cyclosporin A (CSA) levels (trough and peak) in 30 stable renal-transplanted outpatients: 15 with unimpaired renal function (plasma creatinine < 150 mumol/1) and 15 wi th renal impairment (plasma creatinine 150-350 mumol/l). Pulsatility ( PI) and resistive indexes (RI) have been measured in the renal artery at the hilum and in the renal cortex. RI and PI were markedly increase d (p < 0.0001) in the cortex at peak time while in the renal artery no significant changes were observed. These variations were statisticall y related with CSA blood levels (PI = p < 0.02; r = 0.54, RI = p < 0.0 5; r = 0.45). These effects were also found in the presence of renal d amage. CSA dose-dependently reduces cortical blood flow, causing a per sistent arteriolar vasoconstriction and a reduction in diastolic flow. This effect can be measured in man in a noninvasive and repeatable wa y using color Doppler sonograms.