Beneficial effect of atrial natriuretic factor on ischemically injured kidneys in the rat. A new approach to improve early renal function

In a rat experimental study we investigated whether the atrial natriuretic peptide by itself is able to improve early renal function after an ischemic injury. Two groups of Wistar male rats underwent a right nephrectomy and a left renal artery occlusion for 30 min and were infused for 2 hr after ischemia with isotonic saline or rat atrial natriuretic peptides (alpha ANF: 28 amino acids (AP 28) and atriopeptin III (AP 24): 24 amino acids). ANF infusion increased the urinary flow (P less than 0.001), the urinary sodium concentration (P less than 0.001), the sodium excretion rate (P less than 0.0001), and improved the glomerular filtration rate (GFR) recovery (P less than 0.02) determined at the end of the 2-hr infusion period. AP 24 exhibited higher natriuretics activities than AP 28. The effect of both peptides upon GFR recovery was equivalent. These effects of ANF observed after acute ischemia suggest that this peptide may be beneficial on the resumption of renal function in the early phases following transplantation.