EFFECTS OF CILOSTAZOL, A PHOSPHODIESTERASE INHIBITOR, ON URINARY-EXCRETION OF ALBUMIN AND PROSTAGLANDINS IN NON-INSULIN-DEPENDENT DIABETIC-PATIENTS

Microalbuminuria is characteristic in diabetic nephropathy and is thou ght to be influenced by renal hemodynamics, especially by the metaboli sm of prostaglandins (PGs) in glomruli. To reduce urinary albumin excr etion in patients with non-insulin-dependent diabetes mellitus (NIDDM) , we administered 100 mg of cilostazol, a phosphodiesterase inhibitor, daily for 3 months. The urinary albumin index (UAI: mug albumin/mg cr eatinine) decreased significantly after 3 months of administering cilo stazol. Urinary excretions of thromboxane B2 (TXB2), a stable metaboli te of thromboxane A2, decreased significantly after treatment. However , it had no effects on urinary excretions of PGE2 and 6-keto PGF1alpha (6KF), a stable metabolite of prostacyclin. The ratio 6KF/TXB2 has be en known to reflect the renal metabolism of PGs. In this study, urinar y 6KF/TXB2 ratio increased significantly in parallel with a significan t reduction of UAI. Cilostazol had no adverse effects on the control o f blood glucose and lipids. In conclusion, cilostazol has a beneficial effect on UAI in patients with NIDDM by reducing renal production of TXB2, which increases 6KF/TXB2 ratio.