Effects of thromboxane synthesis inhibitor triflusal on renal hemodynamics in microalbuminuric diabetic patients

Triflusal (2-acetoxy-4-trifluormethylbenzoic acid) is a platelet-antiaggregant drug that selectively inhibits thromboxane synthesis with little effect on prostacyclin production. In this study, we evaluated the effect of 5-day administration of 900 mg/day triflusal on glomerular filtration rate (GFR), renal plasma flow (RPF), urinary albumin excretion (UAE), thromboxane B2 (TXB2), 6-ketoprostaglandin F1 alpha (PGF1 alpha), and PGE2 in nine normotensive insulin-dependent diabetic patients with UAE between 30 and 103 micrograms/min. Plasma TXB2 and plasma renin activity (PRA) were also determined. After administration of triflusal, we observed a reduction in microalbuminuria (59 +/- 25 vs. 33 +/- 22 micrograms/min, P less than 0.01), an increase in RPF (648 +/- 119 vs. 722 +/- 134 ml.min-1 x 1.73 m-2, P less than 0.01), and a reduction in filtration fraction (0.24 +/- 0.04 vs. 0.20 +/- 0.03, P less than 0.01). Triflusal produced a significant reduction in both plasma TXB2 (130 +/- 39 vs. 52 +/- 32 pg/ml, P less than 0.02) and urine TXB2 (523 +/- 249 vs. 312 +/- 11 pg/min, P less than 0.02), without changes in PRA and UAE of 6-keto-PGF1 alpha and PGE2. Metabolic control and arterial blood pressure did not change during the study. These results suggest that platelet-antiaggregant therapy can reduce microalbuminuria in diabetic patients. This effect could be mediated by a reduction in the transglomerular hydraulic pressure through a vasodilation of efferent arterioles secondary to renal thromboxane synthesis inhibition.