Decrease of transthyretin synthesis at the blood-cerebrospinal fluid barrier of old sheep.
J Gerontol A Biol Sci Med Sci
; 60(7): 852-8, 2005 Jul.
Article
en En
| MEDLINE
| ID: mdl-16079207
ABSTRACT
Transthyretin (TTR), synthesized by the choroid plexus (CP) and secreted into cerebrospinal fluid (CSF), is involved in thyroxine (T4) transport and chelation of beta-amyloid peptide, attenuating neurotoxicity. To characterize age-related changes in TTR synthesis, CSF and CPs were collected from young adult (1-2 years) and old (>8 years) sheep anesthetized with thiopentone sodium. TTR in old sheep CSF was low compared to young (n = 4 each); however, CP messenger RNA (mRNA) for TTR did not change. CPs were perfused with Ringer containing 14C-leucine to assess de novo protein synthesis, or with 125I-T4 to assess T4 transport. Protein synthesis, including TTR, was reduced in old sheep CP and in newly secreted CSF. 125I-T4 Vmax and Kd (but not Km) were reduced in old sheep CP. These age-related changes suggest reduced capacity of CP to maintain CSF T4 homeostasis and could also reduce chelation of beta-amyloid and be an added risk for Alzheimer's disease.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Envejecimiento
/
Prealbúmina
/
Barrera Hematoencefálica
/
Plexo Coroideo
Límite:
Animals
Idioma:
En
Revista:
J Gerontol A Biol Sci Med Sci
Asunto de la revista:
GERIATRIA
Año:
2005
Tipo del documento:
Article