INTERRELATIONSHIP BETWEEN RENAL MASS AND RENOTROPIN ACTIVITY IN CONSECUTIVE GENERATIONS OF UNINEPHRECTOMIZED MICE

In offspring of uninephrectomized mouse mothers at ages 3, 5 and 7 wee ks (n = 8 in each group) fresh and dry kidney weights, protein content , mean number of glomeruli per microscopic field (GN), mean cumulative fractional glomerular area per microscopic field (GA) and mean number of nuclei per glomerulus (GC) were all significantly increased compar ed to age-matched control offspring of sham nephrectomized mothers. Se ra from mice at ages 3 and 5 weeks, offspring of uninephrectomized mot hers, stimulated mesangial cell proliferation in culture. Surprisingly , fresh and dry renal weight, GN, GA and GC were all significantly inc reased in offspring of sham nephrectomized mothers, daughters of unine phrectomized grandmothers. We speculate that elevated maternal renotro pin transferred via the placenta introduces a modification in the embr yonal interrelationship between renal mass and endogenous renotropin. This modification results in exaggerated embryonal serum renotropic ac tivity extending to puberty. Whether the humoral agent responsible for enhanced mesangial cell proliferation in vitro is identical to renotr opin remains to be elucidated.