CHANGES OF EXTRACELLULAR-MATRIX IN A BABOON (PAPIO-HAMADRYAS) MODEL OF INSULIN-DEPENDENT DIABETES - STUDIES USING ELECTRON-MICROSCOPY AND X-RAY-DIFFRACTION TECHNIQUES

Extracellular matrix plays an important role in many physiological fun ctions and its abnormalities are thought to play a key role in the pat hogenesis of diabetic complications. In this paper we used the techniq ues of electron microscopy, immunostaining and X-ray diffraction to do cument some of the early events in the changes of extracellular matrix in a model of insulin dependent diabetes in baboons. Our results show that thickening of basement membrane and enlargement of mesangium are demonstrable in the glomeruli of prepubertal diabetic baboons within 2 years from the onset of diabetes. Concomitant with this was the accu mulation of type IV collagen and laminin in the mesangium. By contrast , even the very sensitive technique of X-ray diffraction failed to dem onstrate changes in the equatorial direction of collagen molecules of the skin and tendon. We conclude that changes of glomerular extracellu lar matrix are demonstrable early in insulin dependent diabetes even i n prepubertal baboons. These can be used as endpoints in evaluating th e efficacy of pharmacological agents such as aminoguanidine in prevent ing diabetic complications. Copyright (C) 1996 Elsevier Science Irelan d Ltd.