Time-Dependent Alterations in Rat Macrovessels with Type 1 Diabetes

Figure 4

Examples of electron micrographs of aorta. (a) EM micrographs (8,700x magnification) showed a distinct organization of SMCs within each layer, sandwiched by elastic bands (El). The arrowed line in the 50 day control image illustrates a typical elastic band width measurement. In the diabetic aorta, patches of SMC disorganization were evident. Nuclei (N) of cells from diabetic animals often appeared to have a different spatial orientation with invaginated membranes (50 days). The cytoplasm (Cy) was more spread out with finger-like projections in the diabetic samples. The matrix surrounding the SMC contained a mixture of collagen (Col) and elastin (El). (b) Micrographs (21,600x magnification) show SMC nuclei (N) surrounded by cytoplasm (Cy) either rich in cytoskeletal fibers (clear ⊳) as seen in the control samples, or in secretory vesicles (white ⊳) as noted in the diabetic samples. Mitochondria (m) had an increased incidence of swelling or disruption in the diabetic samples. The nuclei contained heterochromatin (→) lining the inner nuclear envelope.