Question:

Chronic stimulation of the renin system causes recruitment of renal renin expressing cells long the media of afferent arterioles as well as hypertrophy of cells in the juxtaglomerular apparatus. Here, we aimed to define the role of NO with regard to the recruitment pattern of renin producing cells and its possible signaling pathways. We considered the hypothesis that the effect of NO involves a direct cellular effect by activating NO-sensitive guanylate cyclase (NO-GC).

Methods:

Mice harboring a cell-specific deletion of NO-GC in renin expressing cells and in preglomerular smooth muscle cells were treated with a combination of low salt diet and the ACE inhibitor enalapril for three weeks.

Results:

This regimen produced juxtaglomerular hypertrophy in NO-GC deficient mice and in controls, whilst recruitment of renin expression in arteriolar smooth muscle cells was only observed in wildtype but not in knockout animals.

Conclusion:

These findings suggest that nitric oxide and concomitant formation of cyclic GMP in preglomerular renin-cell-precursors support recruitment of renin expression along preglomerular vessels but not in the juxtaglomerular apparatus.