Author performed this experiment to define the most important factor preventing the intimal thickening. An endothelium of abdominal aorta in the rat was denuded by two different wires having same caliver. The degree of injury was limited to the endothelial cells in one, and extended to the internal elastic lamina in another. The results showed that at 72 hours, in the case of superficial injury, the entire injury site was covered by new regenerating cells, but in the case of disruption of the internal elastic lamina, the migrating smooth muscle cell completely reached into the intima and resulted in intemal thickening. Similar findings persisted to 1 week later. Above results suggest the most important factor preventing the intimal thickening in endothelial injury is the depth of the injury which limited within the endothelial cells without extending into the internal elastic lamina and medial smooth muscle cells.
Rats ; Animals

Ultrastructural study of the effects of amiodarone on the liver tissue was performed. Rats were fed with amiodarone containing diet and were sacrificerd at 1st, 3rd, 4th, 5th and 8th weeks of experiment. Charateristic lisosomal inclusion bodies were appeared form first week, which were more prominent and increased in size at the 5th and 8th week of experiment. These inclusion bodies were found in hepatocytes, Kupffer cells, bile duct epithelial cells and fibroblasts but most prominent in hepatocytes. The lysosomal inclusion bodies could be divided into four types; those characterized by (1) dense bodies with packed crystaloid contents, (2) multilamellated bodies, (3) irregular shaped bodies with varying electron density and 4. dense bodies containing stacks of fine membranous structures. All types were found in all experimental groups. But the type 1 and 2 were predominent at early stage, while type 3 and 4 were more prominent at later stage According to these findings, the formation of the lysosmal inclusion body was a characteristic change in derangement of phospholipid metabolism. And amiodarone could induce disturbance of phospholipid metabolism in all kinds of cells in liver tissue.
Rats ; Animals