Response of the growth plate of uremic rats to human growth hormone and corticosteroids

Brazilian Journal of Medical and Biological Research

A.p.f. Barbosa²  J.d.p. Silva²  E.c. Fonseca¹  P.m. Lopez¹  M.b.c. Fernandes¹  A. Balduino¹  M.e.l. Duarte¹ 

[1] ,Universidade de Ciências e Saúde de Alagoas Departamento de Patologia Maceió AL ,Brasil

关键词: Corticosteroids;    Growth hormone;    Renal failure;    Growth retardation;    Growth plate;    Insulin-like growth factor I;   

DOI  :  10.1590/S0100-879X2006005000134

来源: SciELO

【 摘 要 】

Children with chronic renal failure in general present growth retardation that is aggravated by corticosteroids. We describe here the effects of methylprednisolone (MP) and recombinant human growth hormone (rhGH) on the growth plate (GP) of uremic rats. Uremia was induced by subtotal nephrectomy in 30-day-old rats, followed by 20 IU kg-1 day-1 rhGH (N = 7) or 3 mg kg-1 day-1 MP (N = 7) or 20 IU kg-1 day-1 rhGH + 3 mg kg-1 day-1 MP (N = 7) treatment for 10 days. Control rats with intact renal function were sham-operated and treated with 3 mg kg-1 day-1 MP (N = 7) or vehicle (N = 7). Uremic rats (N = 7) were used as untreated control animals. Structural alterations in the GP and the expression of anti-proliferating cell nuclear antigen (PCNA) and anti-insulin-like growth factor I (IGF-I) by epiphyseal chondrocytes were evaluated. Uremic MP rats displayed a reduction in the proliferative zone height (59.08 ± 4.54 vs 68.07 ± 7.5 µm, P < 0.05) and modifications in the microarchitecture of the GP. MP and uremia had an additive inhibitory effect on the proliferative activity of GP chondrocytes, lowering the expression of PCNA (19.48 ± 11.13 vs 68.64 ± 7.9% in control, P < 0.0005) and IGF-I (58.53 ± 0.96 vs 84.78 ± 2.93% in control, P < 0.0001), that was counteracted by rhGH. These findings suggest that in uremic rats rhGH therapy improves longitudinal growth by increasing IGF-I synthesis in the GP and by stimulating chondrocyte proliferation.

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