Differential effects of central leptin, insulin, or glucose administration during fasting on the hypothalamic-pituitary-thyroid axis and feeding-related neurons in the arcuate nucleus

Differential effects of central leptin, insulin, or glucose administration during fasting on the hypothalamic-pituitary-thyroid axis and feeding-related neurons in the arcuate nucleus

Autor Fekete, Csaba Google Scholar
Singru, Praful S. Google Scholar
Sanchez, Edith Google Scholar
Sarkar, Sumit Google Scholar
Christoffolete, Marcelo A. Google Scholar
Ribeiro, Rogerio Silicani Autor UNIFESP Google Scholar
Rand, William M. Google Scholar
Emerson, Charles H. Google Scholar
Bianco, Antonio Carlos Autor UNIFESP Google Scholar
Lechan, Ronald M. Google Scholar
Instituição Tufts Univ New England Med Ctr
Hungarian Acad Sci
Brigham & Womens Hosp
Universidade Federal de São Paulo (UNIFESP)
Tufts Univ
Univ Massachusetts
Resumo The reductions in circulating levels of leptin, insulin, and glucose with fasting serve as important homeostasis signals to neurons of the hypothalamic arcuate nucleus that synthesize neuropeptide Y (NPY)/agouti-related protein (AGRP) and alpha-MSH/cocaine and amphetamine-regulated transcript. Because the central administration of leptin is capable of preventing the inhibitory effects of fasting on TRH mRNA in hypophysiotropic neurons primarily through effects on the arcuate nucleus, we determined whether the continuous administration of 30 mU/d insulin or 648 mu g/d glucose into the cerebrospinal fluid by osmotic minipump might also have similar effects on the hypothalamic-pituitary-thyroid axis. As anticipated, the intracerebroventricular infusion of leptin reduced fasting-induced elevations in NPY and AGRP mRNA and increased proopiomelanocortin and cocaine and amphetamine-regulated transcript mRNA in the arcuate nucleus. in addition, leptin prevented fasting-induced reduction in pro-TRH mRNA levels in the paraventricular nucleus and in circulating thyroid hormone levels. in contrast, whereas insulin increased proopiomelanocortin mRNA and both insulin and glucose reduced NPY mRNA in arcuate nucleus neurons, neither prevented the fasting-induced suppression in hypophysiotropic TRH mRNA or circulating thyroid hormone levels. We conclude that insulin and glucose only partially replicate the central effects of leptin and may not be essential components of the hypothalamic-pituitary-thyroid regulatory system during fasting.
Idioma Inglês
Data de publicação 2006-01-01
Publicado em Endocrinology. Chevy Chase: Endocrine Soc, v. 147, n. 1, p. 520-529, 2006.
ISSN 0013-7227 (Sherpa/Romeo, fator de impacto)
Publicador Endocrine Soc
Extensão 520-529
Fonte http://dx.doi.org/10.1210/en.2005-0956
Direito de acesso Acesso aberto Open Access
Tipo Artigo
Web of Science WOS:000234053500058
Endereço permanente http://repositorio.unifesp.br/handle/11600/28618

Exibir registro completo




Arquivo

Arquivo Tamanho Formato Visualização

Não existem arquivos associados a este item.

Este item está nas seguintes coleções

Buscar


Navegar

Minha conta