Postnatal renal development of rats from mothers that received increased sodium intake
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The newborn rat kidney is not fully developed until approximately 12 days after birth. Several lines of evidence suggest that angiotensin II (AII) participates in the postnatal development of the kidney. The aim of the present study was to analyze proliferating cell nuclear antigen (PCNA), fibronectin, α-smooth muscle-actin (α-SM-actin), and AII expression in renal cortex during development in rats born to mothers that received a normal (control) or increased (experimental) sodium intake during pregnancy. Ninety Wistar rats aged 1, 7, 15, and 30 days from the control and experimental groups were killed and the kidneys removed for histological and immunohistochemical studies. The results showed higher fibronectin, α-SM-actin, PCNA, and AII expression in the glomerular and tubulointerstitial areas of the renal cortex of 1- and 7-day-old animals, which decreased with renal development. The animals from the experimental group showed at 1 day of age a decrease in α-SM-actin, fibronectin, PCNA, and AII expression compared with controls of the same age ( P <0.05). In conclusion, our data show that increased sodium intake during pregnancy induces a reduction of α-SM-actin, fibronectin, and PCNA expression in the renal cortex tubulointerstitium and glomeruli of neonatal rats. These alterations may be related to the decrease of AII expression also observed in the renal cortex from these animals.
KeywordsRenal development Angiotensin II Sodium intake Cell proliferation Extracellular matrix
The authors thank Cleonice G.A. da Silva, Erika Delloiagono, and Rubens Fernando de Melo for expert technical assistance. Ana Paula C. Balbi was a recipient of Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, DF, Brazil, fellowship, and Dr. Roberto Silva Costa and Dr. Terezila Machado Coimbra are recipients of Conselho Nacional de Desenvolvimento Científico e Tecnológico, DF, Brazil, fellowships. These results were presented in abstract form at the American Society of Nephrology Meeting, Philadelphia, Pa., November 2002.
- 1.Nigam SK, Aperia AC, Brenner BM (1996) Development and maturation of the kidney. In: Brenner BM, Rector FC (eds): The kidney. Saunders, Philadelphia, pp 72–98Google Scholar
- 4.Thiery JP, Duband JL, Dufour S, Savagner P, Imhof BA (1989) Role of fibronectin in embryogenesis. In: Mosher DF (ed) Biology of extracellular matrix: fibronectin. Academic Press, San Diego, pp 181–212Google Scholar
- 6.Bagby SP, Kirk EA, Mitchell LH, O’Reilly MM, Holden WE, Stenberg PE, Bakke AG (1993) Proliferative synergy of angiotensin II and EGF in porcine aortic vascular smooth muscle cells. Am J Physiol 265:F239–F249Google Scholar
- 9.Gomez RA, Lynch KR, Sturgill BC, Elwood JP, Chevalier RL, Carey RM, Peach MJ (1989) Distribution of renin mRNA and its protein in the developing kidney. Am J Physiol 257: F850–F858Google Scholar
- 20.El Nahas AM, Muchaneta-Kubara EC, Zhang G, Adam A, Goumenos D (1996) Phenotypic modulation of renal cells during experimental and clinical renal scarring. Kidney Int 54:S23–S27Google Scholar
- 21.Geleilete TJ, Melo GC, Costa RS, Volpini RA, Soares TJ, Coimbra TM (2002) Role of myofibroblasts, macrophages, transforming growth factor-beta, endothelin, angiotensin-II, and fibronectin in the progression of tubulointerstitial nephritis induced by gentamicin. J Nephrol 15:633–642PubMedGoogle Scholar
- 23.Chen Y, Lasaitiene D, Gabrielsson BG, Carlsson LM, Billig H, Carlsson B, Marcussen N, Sun XF, Friberg P (2004) Neonatal losartan treatment suppresses renal expression of molecules involved in cell-cell and cell-matrix interactions. J Am Soc Nephrol 15:1232–1243Google Scholar
- 24.Johnson RJ, Iida H, Alpers CE, Majesky MW, Schwartz SM, Pritzl P, Gordon K, Gown AM (1991) Expression of smooth muscle cell phenotype by rat mesangial cells in immune complex nephritis. Alpha-smooth muscle actin is a marker of mesangial cell proliferation. J Clin Invest 87:847–858PubMedGoogle Scholar
- 25.Carey AV, Carey RM, Gomez RA (1992) Expression of alpha-smooth muscle actin in the developing kidney vasculature. Hypertension 19 [Suppl]:168–175Google Scholar