Electron microscopic studies were made in rats to elucidate fine structure of the fat-storing cell and the role of the R.E.S, cells on hepatic uptake of lipid. 1) Fat-storing cell. The fat-storing cell of normal rats is clearly diffrenciated from the R.E.S. cells lining the sinusoid in its fine structure. It is about 10μ diameter, is located in the intercellular space between two hepatocytes or in the Disse space and contains several fat droplets of fairly uniform size in the cytoplasm. However, about 30% of the fat-storing cells have no fat droplets. In rats, in which a fat emulsion was injected intravenously for two weeks, the fat-storing cell with no fat droplet disappeared and the fat droplets in the cytoplasm were significantly increased in number. The reticulum fibers were frequently, observed in close proximity to the fat-storing cell. The lack of microvilli in its cell membrane and very few pinocytic invaginations suggest that this cell has no vigorous phagocytic activity as does the littoral cell. 2) Role of the R.E.S. on hepatic uptake of lipid. Thirty minutes to three hours after forced of cream, numerous electron dense particles of lipid, measuring about 0.1μ, in diameter, -probably chylomicra-were seen in the Disse space and they appeared to be taken up into the hepatocyte by pinocytosis. However, very few or practically no lipid particles, were seen coming into the R.E.S. cell. On the other hand, when a fat emulsion was administered intravenously, lipid droplets about 0.5μ to 1.0μ in diameter, showed to be phagocytized into the Kupffer cells by the process of pinocytotic invagination of the cell membrane or engulfed by the cytoplasmic projections soon after the infusion. However, no lipid drops were seen to be taken up into the hepatocyte at this time. Thirty minutes to two hours after the infusion, numerous small dense particles of lipids, about 0.1μ in diameter, were seen in the Disse space, being pinocytosed into the hepatocytes. They seemed to be liberated from the Kupffer cells in which fat drops have been picked up. When a fat emulsion was administered intravenously under the R.E.S. blockade, uptake of lipid into the Kupffer cell and the subsequent accumulation of lipid in the hepatocyte were delayed. In the uptake of lipid by the hepatocyte, certain physicochemical propeties of the fat droplets may be the determining factors, and the R.E.S. seems to play a role in the disposal of intravenously introduced fat, probably conditioning it in such a way as to enable the hepatocyte to phagocytiz it in its altered form.
1) Three different degrees of the obstructive jaundice were made by means of three differently shaped plastics which encircledthe common bile ducts of dogs at the nearest part of them to the duodenum and the expansion of which made them narrower, namely, complete obstruction, 50 per cent stricture and 30 per cent stricture at one week after the operation and after that, strictures increased in intensity gradually. 2) It generally could be said that most of all changes, both biochemical and histopathologic, became near the maximum untill one week after stricture and did not show marked behavior subsequently. 3) None of some liver function tests except Index of Jaundice expressed difference of strictures correctly and Index of Jaundice, itself, was not directly proportional to the degree of stricture. 4) The most remarkable difference of histopathological findings between complete and incomplete obstructive jaundice was that the cell infiltration was found in the latter and not in the former. 5) No marked difference on liver cell damage was found between the complete and incomplete obstruction.
We studied Talafant's method for the preparation of bilirubin diglucuronide and obtained the results as follows. 1) The molar ratio of bilirubin glucuronide fraction prepared by this method proves to be 1.98 in average, which is quite close to the theoretical value in its purity. 2) Spectrophotometric properties of this fraction coincide well with those of the estertype bilirubin that we know in our laboratory. 3) On the paper chromatography this fraction separates into two spots one of which proves to be a contaminant. 4) The amount of the bilirubin glucuronide fraction harvested by our method is quite minimal (being 2.78% in average), but it is somewhat better than by the original method of Talafant. This seems to be due to the fact that we used the so-called 'crude bilirubin' of Sakamoto et al. as the material.