Atrial natriuretic peptide and dopamine in a rat model of ischemic acute renal failure.

Atrial natriuretic peptide (ANP) has been shown to reverse experimental models of ischemic acute renal failure (ARF). However, infusion of ANP has been associated with systemic hypotension making its use in clinical ARF impractical. Therefore, in this investigation, dopamine (D) was combined with intravenous (i.v.) atriopeptin III (AP III) to determine if this regimen was effective in reversing ARF while preventing systemic hypotension and maintaining renal blood flow (RBF). Four groups of Munich-Wistar rats were studied. Group 1, sham-ARF; Group 2, renal artery (RA) clamp (55 min) followed by i.v. saline; Group 3, RA clamp followed by i.v. AP III-D; and Group 4, RA clamp followed by i.v. D only. All infusions were begun after RA clamp release and continued for four hour. Mean arterial pressure in Group 3 rats given AP III-D were similar to that in Group 2, slightly less than that in Groups 1 and 4 (P less than 0.05), but consistently greater than 100 mm Hg during the four hour infusion. RBF in Group 3 was elevated above the level in Group 1 at P less than 0.05. Glomerular filtration rate (GFR), depressed by 52% in Group 2, was corrected to control (sham-ARF) levels in Group 3. In Group 4 there was a small but significant increase in GFR compared to Group 2 (P less than 0.05), but it remained less than that in sham-ARF or AP III-D treated ARF rats (P less than 0.01). Urine flow rate and urine sodium excretion rate were more than sixfold higher in Group 3 than any other group.(ABSTRACT TRUNCATED AT 250 WORDS)