흰쥐 폐장 미세혈관 구조의 Corrosion Casting에 의한 주사전자현미경적 관찰

Abstract

The pulmonary microvasculatures of normal rats were studied by mean of the vascular casting method. The various methods used previously to demonstrate pulmonary vasculature, concluded with unsatisfactory results. Recently scanning electron microscope(SEM) study of the vascular casts, using Mercox CL-2B as a cast media, have shown three dimensional distribution of the pulmonary vessels, bronchial vessels and alveolar capillary networks. Ten ml of the cast media was injected via inferior vena cava under the speed of 2 ml per min until the thoracic aorta was filled with injected resin. Also osmium impregnation of methyl-methacrylate vascular casts was done to get rid of charge-up phenomena. The processed vascular casts were observed with a Hitach S-520 scanning electron microscope operated at 15 KV. The pulmonary arteries repeated branching as far as the pulmonary arterioles, and the formed rich, basket-like anastomosing capillary networks in the alveolar walls. These capillary networks were collected into the tributaries of the pulmonary veins. The pulmonary arteries usually traveled parallel with the bronchial tree, but the pulmomary veins were situated further away from the bronchial tree. On the surface of the pulmonary arterial casts were longitudinally arrange oval imprints of the endothelial nuclei. While on the surface of the venous casts were more rounded nuclear imprints and revealed marked constriction o circular striations. The alveolar capillaries revealed hexagonal or pentagonal rings of interconnecting vascular networks. In some areas, the vascular rings were fused together, conposed a square network. The bronchial tree was supplied by the bronchial arteries which form the coarse capillary plexus extending as far as the terminal bronchioles. Occasionally the capillary plexus was connected with adjacent capillary networks in and around the alveolar walls. The walls of the pulmonary artery revealed only a single layer of vasa vasorum, But those of pulmonary vein were surrounded by more complicated and well developed vasa vasorum than pulmonary arterial side.