Cholesterol uptake of isolated rat hepatocytes is accelerated by several kinds of phosphatidylcholine

AbstractUptake of cholesterol by isolated rat hepatocytes in a serum-free medium was remarkably enchanced by dispersion with several kinds of phosphatidylcholine. Of the various phosphatidylcholines tested, dilinoylphosphatidylcholine had the strongest accelerating effect, while dipalmitoylphosphatidylcholine was the weakest. The abilities to accelerate cholesterol uptake were in proportion to the content of unsaturated fatty acid in the phosphatidylcholine used. It was confirmed by electron microscopy that there is no relation between the size of the cholesterol-phosphatidylcholine complex and uptake. These data suggest that recognition of unsaturated fatty acids in phosphatidylcholine by isolated cells enhances uptake of cholesterol.Cholesterol uptake(Isolated rat hepatocyte)PhosphatidylcholineUnsaturated fatty acidDioleoylphosphatidylcholineDipalmitoylphosphatidylcholin

〓

このL-Ky.調製法は従来の方法に比較して, 操作が簡単で, 極めて高収量に得られる.又このL-Ky.硫酸塩は2,3の化学的性状から極めて高純度なものであることを確認した.そして十分に生化学的実験に供することができる物質である.L-kynurenine was isolated in a pure crystalline form from rat hair. L-kynurenine which was extracted from rat hair at hot water was separeted with Sephadex G-10 and crystallized from ethanol. The rat hair was very useful for a simplified preparation of L-kynurenine, for hair of 30g yielded 120mg

Relationships between Salivary Melatonin Levels, Quality of Sleep, and Stress in Young Japanese Females

A decrease in the quality of sleep is believed to cause anxiety and worsen depression. Comparisons of salivary melatonin levels with different factors including quality of sleep, state and trait anxieties, and depression, were conducted to examine whether there is a relationship between melatonin, presumably associated with sleep, and psychological stress. The saliva of healthy young females was collected during the daytime and before they went to bed at night (when they were awake and resting in a sitting position), and salivary melatonin levels were measured. The quality of sleep was scored using the Pittsburgh Sleep Quality Index (PSQI)–-a questionnaire method. State and trait anxieties, and depression were scored using other questionnaire methods: the State-Trait Anxiety Inventory (STAI) and Self-Rating Depression Scale (SDS), respectively. The following findings were obtained: (1) Salivary melatonin levels measured during the daytime and before going to bed were higher in females with a high depression score, compared to those with a low score, and there was a correlation between the depression scores and salivary melatonin levels measured at night; and (2) salivary melatonin levels measured before going to bed at night (in a sitting position) were higher in females with a high state anxiety score, suggesting a correlation between state anxiety scores and salivary melatonin levels during the night. Both depression and a sense of anxiety are forms of psychological stress. Therefore, it is assumed that, when a person is under psychological stress, the action of melatonin as a ligand on its receptor is reduced. Meaning psychological stress may induce oxidative stress in the body. On the other hand, no correlation was noted between the quality of sleep and salivary melatonin levels during the night, presumably because saliva was collected when the subjects were awake and sitting, rather than sleeping