[Comparison of renal hemodynamics in 2 types of arterial hypertension, essential and renovascular, in man. Physiopathological implications].

Split renal function tests were studied in 41 patients with unilateral stenosis of the main renal artery in comparison with 36 subjects with essential hypertension. The two populations were matched for sex, age (39 +/- 10 vs 37 +/- 11 years (+/- 1 standard deviation) and systemic arterial pressure (193/114 +/- 29/15 vs 205/110 +/- 30/17 mmHg). The PAH clearance (CPAH) was decreased in essential hypertensives. The decrease was similar in the right (160.3 +/- 56.9 ml/min/m2) and left kidneys (158.7 +/- 45 ml/min/m2). The inulin clearance (Cin) was similar in both kidneys (35.2 +/- 12.5 vs 33.6 +/- 11.6 ml/min/m2). In addition, in essential hypertensive, CPAH was negatively correlated with blood pressure (p less than 0.01). In patients with renal artery stenosis, CPAH of the "stenotic" kidney was reduced (91.5 +/- 47.8 ml/min/m2) as well as Cin (22.9 +/- 9.3 ml/min/m2). In contrast, a significant increase in CPAH (194.1 +/- 63.8 ml/min/m2) and Cin (47.6 +/- 12.6 ml/min/m2) was observed in the contralateral kidney. Kidney function (CPAH and Cin) was not correlated with blood pressure in the "stenotic" kidney. CPAH and Cin of the non stenotic kidney were positively and significantly correlated with systemic arterial pressure (p less than 0.01). Cin was positively correlated with CPAH (p less than 0.001) in all kidneys in renovascular or in sustained essential hypertensives. However, in the contralateral kidney of renovascular hypertensives, a significant upward resetting of the correlation was observed. The Cin/CPAH was increased in the stenotic kidney (25.7 +/- 7.6%), as well as in the contralateral kidney (25.6 +/- 6.2%).(ABSTRACT TRUNCATED AT 250 WORDS)