Document Detail


Spiral ligament pathology in quiet-aged gerbils.
MedLine Citation:
PMID:  12361880     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The ultrastructure of the spiral ligament was compared in aged and young gerbils to assess the involvement of connective tissues in the lateral wall and particularly the fibrocytes in development of presbyacusis. Pathologic features in fibrocytes of senescent gerbils spanned a wide range reflecting different stages of lateral wall involution. All of the type II, IV and V fibrocytes selectively developed cytosolic vacuoles in an early degenerative phase showing minimal strial involvement. Clear spaces indicative of interstitial edema separated the vacuolated cell bodies and their plasmalemmal processes. As a presumed intermediate phase, profiles of amorphous substance apparently derived from apoptosis/necrosis of type II fibrocytes infiltrated the type II fibrocyte area among nearly normal appearing cells. In cochlear turns with advanced strial degeneration, type II fibrocytes disappeared from the spiral prominence area leaving only type I-like fibrocytes occasionally accompanied by a collagen infiltrate. Type V fibrocytes disappeared similarly from the suprastrial area. The extent of atrophy in type II fibrocytes corresponded in general with that in the neighboring stria vascularis. Age-dependent atrophy in the lateral wall largely spared type I fibrocytes except that they often enclosed discrete amorphous foci lacking organelles. The involution thus affected principally the Na,K-ATPase-positive fibrocytes functioning in active uptake rather than passive conductance of K(+). The vacuolization and degeneration exclusive to ATPase-rich fibrocytes and the associated intercellular edema are interpreted as secondary responses, possibly as a result of impaired diffusion of K(+) through downstream marginal cells.
Authors:
Samuel S Spicer; Bradley A Schulte
Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Hearing research     Volume:  172     ISSN:  0378-5955     ISO Abbreviation:  Hear. Res.     Publication Date:  2002 Oct 
Date Detail:
Created Date:  2002-10-03     Completed Date:  2003-03-24     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  7900445     Medline TA:  Hear Res     Country:  Netherlands    
Other Details:
Languages:  eng     Pagination:  172-85     Citation Subset:  IM    
Affiliation:
Department of Pathology and Laboratory Medicine, Medical University of South Carolina, 165 Ashley Avenue, Charleston, SC 29425, USA. schulteb@musc.edu
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MeSH Terms
Descriptor/Qualifier:
Aging / metabolism,  pathology*
Animals
Cochlear Duct / metabolism,  pathology*
Female
Gerbillinae
Ligaments / metabolism,  pathology*
Male
Microscopy, Electron
Potassium / metabolism
Presbycusis / metabolism,  pathology
Sodium-Potassium-Exchanging ATPase / metabolism
Vacuoles / metabolism,  pathology
Grant Support
ID/Acronym/Agency:
P50 DC00422/DC/NIDCD NIH HHS; R01 DC00713/DC/NIDCD NIH HHS
Chemical
Reg. No./Substance:
7440-09-7/Potassium; EC 3.6.3.9/Sodium-Potassium-Exchanging ATPase

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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