BRADYKININ EXCRETION IS INCREASED IN SEVERELY HYPERGLYCEMIC STREPTOZOTOCIN-DIABETIC RATS

The renal kallikrein-kinin system (KKS) was studied in pair-fed strept ozotocin (STZ)-induced diabetic rats and compared with age-matched con trols. Twelve weeks after STZ injection, rats were normotensive, showe d hyperglycemia, proteinuria, polydipsia and reduced glomerular filtra tion rate (GFR) and body weight. The activities of urinary prekallikre in (PRLK) and kallikrein (KLK) were reduced accompanied by an up to 3- fold increase of bradykinin (BK) excretion compared to controls. The i ncreased BK excretion suggests that the renal KKS in STZ-diabetes is a ctivated and that the reduction in urinary PKLK and KLK activity may b e due to an increased consumption of these enzymes or to a negative fe edback mechanism. The stimulation of the renal KKS in STZ-diabetcs cou ld reflect an attempt of the organism to balance glomerular hypertensi on.