STUDIES ON PYRAZINOYLGUANIDINE .6. PREVENTION OF CATARACTS IN STZ-DIABETIC RATS

This study was designed to determine whether pyrazinoyl-guanidine (PZG ) can attenuate cataract development in streptozotocin (STZ)-induced d iabetic rats. After a single, intraperitoneal dose of STZ (45 mg/kg in 0.05 mol/l sodium citrate buffer), Sprague-Dawley rats (250-260 g) we re divided into three groups. Beginning a week later, each group of di abetic rats received twice daily for 24 weeks by gavage one of the fol lowing: vehicle (saline 10 ml/kg), PZG (35 mg/kg), or captopril (15 mg /kg). PZG treatment prevented the development of diabetic cataracts (p = 0.0009 compared to vehicle). In contrast to PZG, 38% of vehicle-tre ated rats exhibited cataracts after 12 weeks, increasing to 89% after 16 weeks. At week 16, 22 % of captopril-treated rats exhibited catarac ts, a 75 % reduction from vehicle-treated rats (p = 0.4289 compared to vehicle; p = 0.0571 compared to PZG). These results indicate that cap topril can attenuate cataract formation in STZ-diabetic rats, whereas PZG completely suppresses it.