Functional and morphological changes in mediobasal hypothalamus of streptozocin-induced diabetic rats. In vitro study of LHRH release

Details

Serval ID
serval:BIB_75D7FA1C1FD7
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Functional and morphological changes in mediobasal hypothalamus of streptozocin-induced diabetic rats. In vitro study of LHRH release
Journal
Diabetes
Author(s)
Bestetti  G. E., Boujon  C. E., Reymond  M. J., Rossi  G. L.
ISSN
0012-1797
Publication state
Published
Issued date
04/1989
Peer-reviewed
Oui
Volume
38
Number
4
Pages
471-6
Notes
In Vitro
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: Apr
Abstract
To investigate the role of the mediobasal hypothalamus (MBH) in diabetic gonadal axis disorders, the MBHs of adult male streptozocin-induced diabetic (STZ-D) rats were examined after incubation in basal conditions or in K+-enriched medium and compared with those of controls. Diabetes lasted 1 mo. Both luteinizing-hormone-releasing hormone (LHRH) release and MBH morphology were studied. After incubation in basal conditions, the LHRH release was unchanged. By light microscopy, the dilated-axon cross sections were more numerous (P less than .01) in the basal arcuate nucleus and in the median eminence. By electron microscopy, the ratio of exocytoses to neurosecretory granules observed in the median eminence axon cross sections was smaller (P less than .05). The total LHRH immunoreactivity, the number of labeled axons, and the amount of positive material in the axons were reduced (P less than .05). After incubation in K+-enriched medium, the LHRH release was markedly reduced (P less than .01). The number and area of dilated-axon cross sections, possibly because of the relation between exocytosis and physiological dilation, were less augmented (P less than .01). Whereas the number of exocytoses and the ratio of exocytoses to neurosecretory granules were not decreased, the total LHRH immunoreactivity and the number of labeled axons were reduced (P less than .05). The releasable LHRH pool therefore seems to be exhausted in control MBH because of long-term stimulation and reduced in the MBH of STZ-D rats because of diabetes. In conclusion, STZ-D causes functional and anatomical MBH lesions that should be pathogenetically relevant for the disorders of the gonadal axis documented in this animal model.
Keywords
Animals Diabetes Mellitus, Experimental/*physiopathology Female Gonadotropin-Releasing Hormone/*secretion Hypothalamus, Middle/drug effects/physiopathology/*secretion Median Eminence/pathology/ultrastructure Microscopy, Electron Potassium/pharmacology Rats Rats, Inbred Strains Reference Values
Pubmed
Web of science
Create date
11/02/2008 14:12
Last modification date
20/08/2019 14:33
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