Glomerular renin synthesis and storage in the remnant kidney in the rat

The intrarenal renin-angiotensin system can exert local control of the nephron and its circulation. In the subtotally nephrectomized model of chronic renal disease in the rat, angiotensin appears to play a prominent role in glomerular function. Glomeruli in this model demonstrate greater staining for intraglomerular renin by immunofluorescence microscopy than do those in control rats. Glomeruli from remnant nephrons contain increased renin content. Also, glomeruli from remnant nephrons contain an increased proportion of the mRNA for renin. Adriamycin-induced nephrosis did not evoke the same degree of renin staining and did not lead to increased glomerular expression of the renin gene, findings that argue against permselective defects and glomerular trapping as the sole cause of the glomerular renin in the remnant kidney model. Thus, renin synthesis and accumulation occur in the remnant glomerulus and this migration may underlie in part the dependence of glomerular function on the renin-angiotensin system in this model.