Ocular Lesions in Rats Rendered Chronically Diabetic with Streptozotocin

Abstract

The first results of a long-term study on rats rendered chronically diabetic with streptozotocin are presented. Besides well-known ocular changes (formation of cataracts, refractive changes, neovascularisation of iris, loss of retinal capillary endothelial and mural cells; variations in capillary diameter due to fusiform capillary microaneurysms), the formation of typical saccular microaneurysms, qualitative and quantitative changes of the capillary basement membrane ultrastructure have been observed. The basement membranes of diabetic animals showed focal thickenings containing basement membranelike and/or fibrillar material with the periodicity of collagen, but an increase of mean basement membrane width was not found compared with the controls.

Study on Changes in Basal Lamina Width of Mucosal Epithelium and of Capillary in the Lamina propria of Murine Stomach in Advance of Age

“…Capillary basal lamina thickening is found in multiple organs in diabetes mellitus [3,6,12,13] as well as in aging. The exact physiopathological mechanism leading to the basement membrane change remains un known, but the recent hypothesis proposes that basement membrane heparan sulfate proteoglycan synthesis is decreased in the diabetic state, and that the basal lamina thickening is the result of compensatory hy persecretion of type IV collagen and laminin [14], while it has been postulated that local factors, such as vasospasms or endothelial leakage, act as triggering events for thicken ing of capillary basal lamina [15].…”

“…Thickening of the basal lamina of capil laries in the kidney [2], skeletal muscle [3], heart muscle [4,5] and the retina [6] has been recognized as a marker of aging of these organs and tissues in both human and sev eral kinds of experimental animals. More over, thickening of basal lamina of the epi thelium in proportion to advancing age has been noted in the rat kidney [2] and the human retina [7].…”

Ultrastructure of the Ageing Retinal Vascular System, with Special Reference to Quantitative and Qualitative Changes of Capillary Basement Membranes

“…The present paper is basically a synthesis of results, published previously in two papers of the ophthalmic literature [16,17]. It reports our findings in the retina of spiny mice and rats by measuring the diameter of retinal capillaries and the width of their BM with respect to age, using a modifica tion of the morphometrical method of Siperstein et al [24].…”

Relation of diabetic control to development of microvascular complications

“…Studies in diabetic rats, dogs and monkeys have shown that glomerular and/or retinal capillary membrane thickening undoubtedly develops after the induction of diabetes [60][61][62][63][64][65][66][67][68][69][70][71]. This includes the streptozotocin-hyperglycaemic rats studied by Mauer [71].…”