Atrial natriuretic peptide (ANP) is a cardiac hormone with natriuretic and 
diuretic effects. To better define the ANP hormonal system in the nephrotic 
syndrome, a condition associated with renal sodium retention, we undertook a 
study of glomerular ANP receptors in rats with puromycin aminonucleoside-induced 
nephrotic syndrome and in pair-fed controls. Nephrotic rats had significantly 
decreased serum albumin and total protein and significantly increased serum 
cholesterol, triglycerides and 24 hour urinary protein excretion. Plasma level 
of atrial natriuretic peptide was similar in both groups of rats. Competition 
binding inhibition studies in isolated glomeruli demonstrated one binding site 
in both groups of rats. The density of ANP binding sites in isolated glomeruli 
was similar in nephrotic and pair-fed rats while the binding affinity was 
increased significantly in the nephrotic rats. This is the first study to 
demonstrate alterations in renal ANP receptors in the nephrotic syndrome. 
Further studies will be necessary to determine whether alterations in glomerular 
ANP receptors contribute to renal sodium retention in the nephrotic syndrome.