Hypervascularization in the magnocellular nuclei of the rat hypothalamus: relationship with the distribution of aquaporin-4 and markers of energy metabolism

Détails

ID Serval
serval:BIB_52027DD312E1
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Hypervascularization in the magnocellular nuclei of the rat hypothalamus: relationship with the distribution of aquaporin-4 and markers of energy metabolism
Périodique
Journal of Neuroendocrinology
Auteur(s)
Badaut  J., Nehlig  A., Verbavatz  J., Stoeckel  M., Freund-Mercier  M. J., Lasbennes  F.
ISSN
0953-8194
Statut éditorial
Publié
Date de publication
10/2000
Peer-reviewed
Oui
Volume
12
Numéro
10
Pages
960-9
Notes
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: Oct
Résumé
In the magnocellular nuclei of the hypothalamus, there is a rich vascular network for which the function remains to be established. In the supraoptic nucleus, the high vascular density may be one element, which together with the water channel aquaporin-4 expressed in the astrocytes, is related to a role in osmoreception. We tested the osmoreception hypothesis by studying the correlation between vascular and cellular densities in the paraventricular nucleus and the supraoptic nucleus. Whether aquaporin-4 is likely to contribute to osmoreception was tested by studying the distribution in the magnocellular nuclei of the hypothalamus. The high vascular density may also reflect a high metabolic activity due to the synthesis of vasopressin and oxytocin. This metabolic hypothesis was tested by studying the regional cytochrome oxidase histochemistry, the local cerebral blood flow, and the density of glucose transporter type-1 in the supraoptic and paraventricular nuclei. All the magnocellular nuclei were characterized by an extended and intense aquaporin-4 labelling and a weak cytochrome oxidase histochemistry. The highest vascular density was found in the supraoptic nucleus and the magnocellular regions of the paraventricular nucleus. The local cerebral blood flow rates were surprisingly low in the paraventricular nucleus and the supraoptic nucleus in comparison to the cerebral cortex. Furthermore in these nuclei, the antibody for glucose transporter type-1 revealed two populations of vessels differing by their labelling intensity. The similarities observed between the different nuclei suggest that, in the hypothalamus, all magnocellular regions sense the plasma osmolarity. The low local cerebral blood flow, and the patterns of glucose transporter type-1 labelling and cytochrome oxidase histochemistry suggest that the high vascularization of these hypothalamic nuclei is not related to a high metabolic capacity in basal conditions.
Mots-clé
Animals Aquaporin 4 Aquaporins/metabolism Biological Markers Blood Vessels/anatomy & histology/metabolism Cerebrovascular Circulation Energy Metabolism Glucose Transporter Type 1 Histocytochemistry Male Monosaccharide Transport Proteins/metabolism Paraventricular Hypothalamic Nucleus/*blood supply Rats Rats, Wistar Supraoptic Nucleus/*blood supply Tissue Distribution
Pubmed
Web of science
Création de la notice
29/01/2008 15:22
Dernière modification de la notice
03/03/2018 17:12
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