The study of renin-angiotensin-aldosterone in experimental diabetes mellitus

It is generally accepted that hypertension and other vascular pathologies i ncrease in diabetes mellitus (DM) patients as a result of the renin-angiote nsin-aldosterone (RAA) system. In this study, changes in the renin-angioten sin-aldosterone (RAA) system level was determined in Streptozotocin (STZ)-i njected rats. A total of 46 female Wistar albino rats (180-220 g body weigh t) was utilized in these experiments. STZ was given intraperitoneally to in duce diabetes in rats. Streptozotocin (60 mg kg(-1) body weight) was dissol ved in 0.1 M citrate-phosphate buffer (pH 4-5). The non-diabetic rats were injected with sterilized buffer alone to act as a control group. Blood gluc ose levels were 398 +/- 8.2 mg dl(-1), 488 +/- 11.75 mg dl(-1) and 658 +/- 29.6 mg dl(-1) at days 3, 12 and 30 respectively. The level of plasma renin activity (PRA) was measured as 7.69 +/- 1.07 ng ml(-1) h(-1); 1.82 +/- 0.2 2 ng ml(-1) h(-1) and 0.67 +/- 0.12 ng ml(-1) h(-1) at days 3, 12 and 30, r espectively. These values showed that the PRA levels are decreased with inc reased time period. Serum angiotensin converting enzyme (ACE, E.C. 3.4.15.1 ) levels were increased at days 12 and 30 (p < 0.05 and p < 0.005), whereas serum aldosterone levels were increased at days 3 and 12 (p < 0.05). The l evel of urea and creatinine increased at days 12 and 30 (p < 0.05 and p < 0 .005, respectively) when compared to the control group. The data from these experiments indicate that the PRA level decreased whereas ACE activity lev el increased in diabetic rats compared with the control. Aldosterone levels increased at the first stage of the experiment, but then decreased by the end of the experiment as a result of changes in renin and ACE levels. Copyr ight (C) 1999 John Wiley & Sons, Ltd.