Functional and morphological aspects of impaired TRH release by mediobasal hypothalamus of STZ-induced diabetic rats

Détails

ID Serval
serval:BIB_8DEB6245D23B
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Functional and morphological aspects of impaired TRH release by mediobasal hypothalamus of STZ-induced diabetic rats
Périodique
Diabetes
Auteur(s)
Bestetti  G. E., Reymond  M. J., Boujon  C. E., Lemarchand-Beraud  T., Rossi  G. L.
ISSN
0012-1797
Statut éditorial
Publié
Date de publication
11/1989
Peer-reviewed
Oui
Volume
38
Numéro
11
Pages
1351-6
Notes
In Vitro
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: Nov
Résumé
Streptozocin-induced diabetes (STZ-D) in rats is associated with marked hypothyroidism characterized by functional impairment and structural lesions of the pituitary-thyroid axis. Degenerative axonal lesions, which can be prevented by insulin administration, have been reported in the mediobasal hypothalamus (MBH) of STZ-D rats. However, direct evidence connecting anatomic MBH lesions with functional impairment is still missing. We therefore performed a combined functional and morphological investigation in 4-mo-old STZ-D male rats (diabetes lasted 1 mo), applying an in vitro model to study in the same isolated MBH 1) the basal and depolarization-induced thyrotropin-releasing hormone (TRH) release during two successive incubations of 20 min each and 2) morphological and morphometric aspects, including distribution and amount (densitometric evaluation) of immunoreactive TRH in the incubated tissue. In basal conditions, TRH release was much lower in diabetic than control MBH during both incubations (P less than .01 vs. P less than .05). In depolarizing conditions, TRH release was increased during the second incubation in control (P less than .05) and during both incubations in diabetic (P less than .01) rats, the percentage increase of the TRH release due to ionic stimulation being much higher in diabetic than control animals (P less than .01). As determined by light-microscope morphometry, the total area of dilated-axon cross sections was larger in diabetic than control MBH under basal conditions (P less than .01), thus confirming degenerative axonopathy in diabetic rats. By densitometry determination, the amount of immunoreactive TRH was higher in stimulated diabetic MBH compared with both stimulated control and basal diabetic MBH (P less than .01).(ABSTRACT TRUNCATED AT 250 WORDS)
Mots-clé
Animals Axons/pathology Blood Glucose/metabolism Body Weight Diabetes Mellitus, Experimental/*metabolism/pathology Hypothalamus, Middle/*metabolism/pathology Hypothyroidism/etiology/metabolism Immunohistochemistry Male Median Eminence/metabolism Rats Rats, Inbred Strains Thyrotropin-Releasing Hormone/*metabolism
Pubmed
Web of science
Création de la notice
11/02/2008 15:12
Dernière modification de la notice
03/03/2018 19:17
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