Atrial natriuretic peptide inhibits mesangial cell proliferation induced by early postnephrectomy serum

Rat kidney mesangial or tubular cells were grown in tissue culture medium supplemented with sera of 20 sham-operated vs. 20 nephrectomized Charles River rats. Each cell sample was grown with or without addition of atrial natriuretic peptide (ANP) to the medium. ANP completely abolished the growth stimulatory effect of postnephrectomy serum [i.e., effect of renotropic factor(s) present in the serum] on mesangium cells. Tubular cell proliferation was unchanged. We propose that interaction between renotropin and atrial natriutetic peptide activity might be one of the possible mechanisms regulating compensatory renal growth following nephrectomy.