Interrelationships between thyroid hormones and (IGFs)

• Autores: Ana María Pascual-Leone Pascual
• Localización: Anales de la Real Academia Nacional de Farmacia, ISSN-e 1697-4298, ISSN 0034-0618, Nº. 4 2, 2000, pág. 2
• Idioma: inglés
• Enlaces
  • Texto completo
• Resumen

  • Thyroid hormones and insulin-like growth factors (IGFs) play a key role in growth regulation during immature stages of life. Both endocrine factors are involved in the regulation of metabolism and their secretion is decreased in a situation of undernutrition. Although the interaction between thyroid hormones and IGFs represents a complex question, its study has produced interesting data to Biology of Development and the current Molecular Endocrinology. The interrelationship between classic hormones and growth factors, especially during periods of enhanced cell proliferation such as perinatal development, remains largely unknown. The present work shows the IGFs regulation when thyroxine (T4) is administered to neonatal and adult rats submitted to two experimental models: a) hypothyroidism induced by thyroidectomy, and b) diabetes induced by streptozotocin administration. Serum levels of IGF-I and -II in neonatal rats and IGF-I in adults as well as their liver mRNA expression were determined. It is concluded that, in addition to the mediating effect of insulin in neonatal rats and of GH in adults, thyroid hormones seem to have a direct effect on IGFs secretion by regulating liver 5´-deiodinase and, consequently, inducing changes in liver synthesis and plasma levels of T3.