Distribution of the collagen IV isoforms in human Bruch's membrane.
OBJECTIVE
To determine the distribution of the alpha1 to alpha6 chains of type IV collagen in Bruch's membrane of the human posterior pole.


METHODS
Cryosections (10 micro m) from 18 human eyes (20 months to 83 years old) were acid treated, blocked with 10% normal goat serum, incubated for 1 hour with monoclonal antibodies against type IV collagen isoform specific peptides at 1:75 dilution, and visualised with an ABC staining kit.


RESULTS
In Bruch's membrane, the alpha1(IV) and alpha2(IV) chains were identified in retinal pigment epithelial (10/18 = 55%) and choriocapillaris basement membranes (18/18 = 100%); the alpha3(IV), alpha4(IV), and alpha5(IV) chains were also found in the retinal pigment epithelial basement membrane (13/18 = 72%). In the choroid, the alpha1(IV) and alpha2(IV) chains were detected in the blood vessels (18/18=100%). The alpha6(IV) chain was not identified in any sections.


CONCLUSIONS
The heterogeneous distribution of alpha1-2(IV) and alpha3-5(IV) in Bruch's membrane could give insights into the function of this structure in health, ageing, and diseases such as age related macular degeneration.
Chen
L
L
Department of Ophthalmology, University of California, Davis, USA.
Miyamura
N
N
Ninomiya
Y
Y
Handa
J T
JT
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001485:Basement Membrane / Q000737:chemistry; D016570:Bruch Membrane / Q000737:chemistry*; D002648:Child; D002675:Child, Preschool; D002829:Choroid / Q000098:blood supply; D024141:Collagen Type IV / Q000032:analysis*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D007223:Infant; D008875:Middle Aged; D010857:Pigment Epithelium of Eye / Q000737:chemistry; D020033:Protein Isoforms
D024141:Collagen Type IV; D020033:Protein Isoforms