Br J Ophthalmol 87:212-215 doi:10.1136/bjo.87.2.212
  • Original Article
    • Laboratory science

Distribution of the collagen IV isoforms in human Bruch’s membrane

  1. L Chen1,*,
  2. N Miyamura1,
  3. Y Ninomiya2,
  4. J T Handa3
  1. 1Department of Ophthalmology, University of California, Davis, CA, USA
  2. 2Department of Molecular Biology and Biochemistry, Okayama University Medical School, Okayama, Japan
  3. 3Wilmer Eye Institute, Johns Hopkins Medical Institutes, Baltimore, MD, USA
  1. Correspondence to: James T Handa, MD, Michael B Panitch Macular Degeneration Laboratory; 3–109 Jefferson Street Building, 600 N Wolfe Street, Baltimore, MD 21287, USA; jthanda{at}
  • Accepted 22 August 2002


Aims: To determine the distribution of the α1 to α6 chains of type IV collagen in Bruch’s membrane of the human posterior pole.

Methods: Cryosections (10 μm) 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 α1(IV) and α2(IV) chains were identified in retinal pigment epithelial (10/18 = 55%) and choriocapillaris basement membranes (18/18 = 100%); the α3(IV), α4(IV), and α5(IV) chains were also found in the retinal pigment epithelial basement membrane (13/18 = 72%). In the choroid, the α1(IV) and α2(IV) chains were detected in the blood vessels (18/18=100%). The α6(IV) chain was not identified in any sections.

Conclusion: The heterogeneous distribution of α1–2(IV) and α3–5(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.


  • * Current address: Scheie Eye Institute, Philadelphia, PA, USA