Angiotensin (ANG)-(1-7) constitutes an important functional end-product of the renin-angiotensin-aldosterone system that acts to balance the physiological actions of ANG II. In the kidney, ANG-(1-7) exerts beneficial effects by inhibiting growth-promoting pathways and reducing
proteinuria. We examined whether a 2-wk treatment with a daily dose of ANG-(1-7) (0.6 mg·kg(-1)·day(-1)) exerts renoprotective effects in
salt-loaded
stroke-prone spontaneously hypertensive rats (SHRSP).
Body weight, glycemia, triglyceridemia, cholesterolemia, as well as plasma levels of Na+ and K+ were determined both at the beginning and at the end of the treatment. Also, the weekly evolution of arterial blood pressure,
proteinuria, and
creatinine clearance was evaluated. Renal
fibrosis was determined by Masson's trichrome staining.
Interleukin (IL)-6,
tumor necrosis factor (TNF)-α, and nuclear factor-κB (NF-κB) levels were determined by immunohistochemistry and confirmed by Western blotting analysis. The levels of glomerular
nephrin were assessed by immunofluorescence. Chronic administration of ANG-(1-7) normalized arterial pressure, reduced glycemia and triglyceridemia, improved
proteinuria, and ameliorated structural alterations in the kidney of SHRSP as shown by a restoration of glomerular
nephrin levels as detected by immunofluorescence. These results were accompanied with a decrease in both the immunostaining and abundance of
IL-6, TNF-α, and NF-κB. In this context, the current study provides strong evidence for a protective role of ANG-(1-7) in the kidney.