Pro-inflammatory role of angiotensin II in mercuric chloride-induced nephropathy in rats

Figures & data

Figure 1.  Renal interstitial expression of angiotensin II (AngII), intercellular adhesion molecule-1 (ICAM-1), inducible nitric oxide synthase (iNOS), and macrophages (ED-1) in HgCl₂-induced nephropathy. Increased expressions of (a) Ang II, (b) ICAM-1, (c) ED-1 (macrophages), and (d) iNOS were observed in all HgCl₂-treated rats. Losartan and Enalapril diminished the induced expression of those molecules. Values shown are mean (± SD) from 10 rats/group.

Figure 2.  Renal tubular expressions of angiotensin II (AngII), intercellular adhesion molecule-1 (ICAM-1), and inducible nitric oxide synthase (iNOS) in HgCl₂-induced nephropathy. Increased expressions of (a) Ang II, (b) ICAM-1, and (c) iNOS were observed in all HgCl₂-treated rats. Enalapril diminished the expression of AngII and both Enalapril and Losartan diminished the expressions of ICAM-1 and INOS.

Figure 3.  Immunofluorescence of renal angiotensin II (AngII), intercellular adhesion molecule-1 (ICAM-1), inducible nitric oxide synthase (iNOS), and macrophages (ED-1) in HgCl₂-induced nephropathy. (a) Intense tubular expression of Ang II in tubules (arrows) and in interstitial cells (arrowheads). Magnification: ×100. (b) ICAM-1 expression in brush border of proximal tubules (arrows) and in interstitial cells (arrowheads). Magnification: ×400. (c) Increased infiltration of ED-1⁺ cells in tubulo-interstitial areas (arrows). Magnification: ×400. (d) iNOS⁺ cells in tubulo-interstitial areas (arrows). Magnification: ×400.

Figure 4.  Glomerular expression of angiotensin II (AngII), intercellular adhesion molecule-1 (ICAM-1), inducible nitric oxide synthase (iNOS), and macrophages (ED-1) in HgCl₂-induced nephropathy. In general, expression of (a) Ang II and the (b, c, d) pro-inflammatory molecules remained similar to control values. Values shown are mean (± SD) from 10 rats/group.

Table 1.  Proximal tubule changes in HgCl₂ nephropathy.

Groups	Focal necrosis (%)	Complete necrosis (%)
Control	2.84 ± 1.45^a	0
HgCl2	10.80 ± 4.52	4.51 ± 5.27
HgCl2- Losartan	3.82 ± 2.10^a	0.72 ± 0.92^a
HgCl2 -Enalapril	3.79 ± 1.12^a	1.21 ± 0.80^a

Values shown are mean (± SD) from 10 rats/group.

^ap < 0.001 vs HgCl₂-only group.

Table 2.  Serum creatinine and renal protein excretion in HgCl₂ nephropathy.

Groups	Creatinine (mg/dl)	Proteinuria (mg/24 hr)
Control	0.75 ± 0.30	0.87 ± 0.23
HgCl2	0.79 ± 0.18	0.93 ± 1.02
HgCl2-Losartan	1.15 ± 0.91	0.54 ± 0.56
HgCl2 -Enalapril	0.68 ± 0.15	1.33 ± 1.93

Values shown are mean (± SD) from 10 rats/group.

Table 3.  Interstitial and tubular correlations of angiotensin II, ICAM-1, iNOS, and infiltration of ED-1+ cells.

Parameters	Pearson (r)	p-value
Interstitial expression of Ang II vs ICAM-1	0.6603	0.0140
Interstitial expression of ICAM-1 vs ED-1	0.8536	0.0002
Interstitial expression of ICAM-1 vs iNOS	0.8554	0.0002
Interstitial expression of ED-1 vs iNOS	0.6616	0.0138
Tubular expression of Ang II vs ICAM-1	0.6375	0.0191
Tubular expression of Ang II vs iNOS	0.4077	NS

Ang II, Angiotensin II; ICAM-1, intercellular adhesion molecule-1; ED-1, monocyte/macrophages; iNOS, Inducible nitric oxide synthase; NS, no significant.