okura T

Changes in Bruch's Membrane in Experimental Hypercholesteremia in Rats

PURPOSE We investigated the effect of high cholesterol diet for the aging changes in Bruchs membrane of rats. METHODS After feeding a 4% cholesterol diet for 15 weeks to three young rats 3 months old and four aged rats 23 months old, we observed the morphological changes of Bruchs membrane by electron microscopy, and made a comparison with rats fed an ordinary diet. RESULTS In one young rat fed a high-cholesterol diet, the endothelial basement membrane of the choriocapillaris formed multiple folds separated from the plasma membrane of the endothelium and showed lamellar thickening and crack in some areas. The elastic fiber layer in Bruchs membrane disappeared partly and some new microfibrils appeared. In one aged rat fed a high-cholesterol diet, the endothelial basement membrane of the choriocapillaris showed more lamellar thickening with lumps in some parts. Compared with rats fed an ordinary diet, rats fed a high-cholesterol diet showed thickening of the basement membrane and the changes were more severe. CONCLUSIONS Our data indicated that high-cholesterol diet might promote age-related changes of Bruchs membrane.

[Age-related changes in Bruch's membrane in rats].

PURPOSE We investigated rats were worth the experimental animal on the aging changes in Bruchs membrane. METHODS We did an ultramicromorphological study on the aging changes in Bruchs membrane, in male Sprauge-Dawley rats at 1,6,12 and 27 months after their birth. RESULTS With the aging, the basement membranes on both sides of Bruchs membrane have become thick. At 6 months of age, the basement membranes of the endothelial cells of the choriocapillaris were found to be multilayered and cracked and pseudopodia of the endothelium were also observed toward the retinal pigment epithelium. At 12 months of age, we found vacuoles in the basal portion of the retinal pigment epithelium, as well as fibrillae and a part of the process of a cell in the outer collagenous zone correspond with the portion of the multilayered and cracked basement membranes of the endothelial cells of the choriocapillaris. At the age of 27 months, the basement membranes were thicker and a basal laminar deposit was seen. Prominent changes such as disappearance of the elastic fibers and increase of the collagenous fibers and fibrillae were also seen in some portions. CONCLUSIONS Thus, the aging changes in Bruchs membrane of rats were remarkably reinforced in accordance with the age, it were appeared these rats were worth the experimental animal.