Atrial natriuretic peptide blocks renin response to renal hypotension

The authors have reported that the renin response to systemic hypotension is inhibited in the presence of elevated atrial pressure and that elevations in atrial pressure of similar or larger magnitude cause graded increases in plasma atrial natriuretic peptide (ANP). Therefore they tested the hypothesis that comparable increments in plasma ANP can inhibit renal hypotension-induced increases in plasma renin activity (PRA) in conscious dogs. Renal perfusion pressure was controlled using cuffs implanted around the abdominal aorta just above the renal arteries. Reducing renal perfusion pressure by 10 or 30% of control caused graded increases in PRA. Infusion of 1-28 rat ANP, which increased plasma ANP by 34.8 +/- 7.5 (SE) pg/ml, eliminated increases in PRA in response to a 10% reduction in renal perfusion pressure and markedly inhibited the response to a 30% pressure reduction. ANP and PRA were measured by radioimmunoassay. These results indicate that increments in plasma ANP which reproduce endogenous release inhibit renal hypotension-induced stimulation of PRA. Furthermore, the results provide an explanation for the inhibition of the renin response to renal hypotension during elevate atrial pressure