Response of the growth plate of uremic rats to human growth hormone and corticosteroids
AUTOR(ES)
Barbosa, A.P.F., Silva, J.D.P., Fonseca, E.C., Lopez, P.M., Fernandes, M.B.C., Balduino, A., Duarte, M.E.L.
FONTE
Brazilian Journal of Medical and Biological Research
DATA DE PUBLICAÇÃO
11/06/2007
RESUMO
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.
Documentos Relacionados
- Metabolic response to human growth hormone during prolonged starvation
- The effect of administration of human growth hormone on the plasma growth hormone, cortisol, glucose, and free fatty acid response to insulin: evidence for growth hormone autoregulation in man
- Plasma growth hormone responses to constant infusions of human pancreatic growth hormone releasing factor. Intermittent secretion or response attenuation.
- Growth hormone response to growth hormone-releasing peptide-2 in growth hormone-deficient Little mice
- Growth Hormone Responses to Thyroid Hormone in the Neonatal Rat: RESISTANCE AND ANAMNESTIC RESPONSE