Effect of Oral Adsorbent on the Progression of Diabetic Nephropathy

Dr. K. Okada, Second Department of Internal Medicine, Nihon University School of Medicine, Itabashi-ku, Tokyo 173 (Japan) Dear Sir, It has been reported that the administration of an oral adsorbent delays the progression of chronic renal failure in man [1]. Although its mechanism is unclear, we have recently reported that the administration of an oral adsorbent delays the occurrence of glomerular sclerosis by delaying the appearance of glomerular hypertrophy, systemic hypertension and proteinuria in nephrectomized rats [2]. Since it is postulated that all kidney diseases progress through the same nonimmunological mechanisms [3], it is suggested that oral adsorbents have a protective effect on the progression of diabetic nephropathy as well as nondiabetic renal failure. However, it is not clear when an oral adsorbent should be prescribed in diabetic nephropathy. We therefore examined whether the administration of an oral adsorbent at an early stage had an effect on diabetic nephropathy. 36 male Sprague-Dawley rats weighing 120-135 g were made diabetic, following a 24-hour fast, by intravenous injection of 65 mg streptozotocin/kg body weight (BW) and intraperitoneal injection of 0.6 ml/l00 g BW of 30% glucose in 0.9% saline solution. Induction of the diabetic state was confirmed by the development of a persistent and heavy glycosuria and a blood glucose (BG) level in excess of 400 mg/dl. 24 rats demonstrating the diabetic state were on ad libitum water and standard rat chow (CE-2, Clea Japan Inc., Tokyo). After 4 weeks, the rats underwent uninephrectomy by resection. Two weeks later, the rats were divided