Structural organization of collagen fibrils in media aortic wall.
Small-angle X-ray diffraction patterns of bovine, human and porcine media aortic wall show meridional reflections corresponding to a periodicity which suggest a molecular packing typical of tendon collagen. However the meridional intensity distribution of stretched air dried aortic samples appears different from that of air-dried tendon, probably because of the presence of a large amount of type III collagen with the environment, which are specific for aortic tissue. The stretched wet aortic samples show a marked decrease in intensity, revealing an extensive disorder in the axially-projected structure of the fibrils. When a loading system simulating the effect of blood pressure is applied to a ring of aorta, no evidence of orientation of collagen is seen by X-ray diffraction, as would be expected if collagen fibrils had an isotropic distribution inside the aorta media. Scanning electroni microscopy supports the existence of a network of collagen fibrils surrounding elastic lamellae.
D000328:Adult; D000818:Animals; D001011:Aorta / Q000648:ultrastructure*; D002417:Cattle; D003094:Collagen / Q000032:analysis*; D003593:Cytoplasm / Q000648:ultrastructure*; D003599:Cytoskeleton / Q000648:ultrastructure*; D006801:Humans; D008297:Male; D008855:Microscopy, Electron, Scanning; D013552:Swine; D014961:X-Ray Diffraction
D003094:Collagen