effect of 72 hours' continuous infusion of long acting natriuretic peptide on acute ischemic renal failure in the rat

ABSTRACT

Atrial natriuretic peptide [ANP1-28] protects the kidneys against acute renal failure in animals; however, its use in humans has been disappointing. Long acting natriuretic peptide [LANP1-30] has natriuretic and diuretic actions similar to ANP1-28, but it has a longer halflife and a diff e rent receptor site of action. These differences comprise this study, specifically, to see if LANP1-30 has better renal protection than ANP1-28, which may make it useful in the treatment of acute renal failure. Subjects/Three groups of male Sprague- Dawley rats were used, each with a body weight between 250-300 gm. Group 1 [ischemia only, n=6] had right nephrectomy followed by 30 minutes of left renal pedicle clamping. Group 2 [LANP Peptide treated, n=7] had renal ischemia similar to Group 1, followed by an intraperitoneal bolus of 10 mg of LANP1-30 and placement of mini-osmotic pumps delivering LANP1-30 at a rate of 1mg/hr for 72 hours. Group 3 [controls, n=6] was used to measure the baseline creatinine level and had no renal ischemia or surgery. 72 hours post renal ischemia, the weight loss in the ischemia group was similar to the peptide treated group [7.65 +/- 1.14% and 10.03 +/- 0.9% body weight loss, re s p e c t i v e l y, p=0.126]. The ischemia group had significantly higher creatinine levels compared to the controls [66.3 +/- 5.3 versus 30.1 +/- 0.9 mmol/l, p=0.002]. The peptide treated group had higher creatinine [174.1 +/- 77.8 versus 66.3 +/- 5.3 mol/l, p=0.035] and LANP1-30 levels [673.14 +/- 69.64 versus 45.83 +/- 8.45 pg/ml, p=0.001] than the ischemia group. Prolonged use of LANP1-30 has no renal protective effect