Significant Increase In Cholesterol Research Articles

Cytolytic mechanism of attenuated preparation (OK-432) of Streptococcus haemolyticus against ascites hepatoma, AH 130 and AH 41 C cells.

In order to gain insight into the mechanisms by which OK-432 (a lyophilized preparation of an attenuated strain of Streptococcus haemolyticus) treatment lyzed tumor cells, the in vivo effect of the agent on some enzymes, cellular components and surface properties of ascites hepatoma, AH 130 and AH 41 C cells, was studied in comparison with the effect of 5-fluorouracil (5FU) and cyclophosphamide (CP) on these parameters. Administration of OK-432 (0.5 mg/rat/day) to AH 130 cell-bearing rats for 4 days was found to enhance leakage of intracellular potassium and calcium, cause a decrease in hexokinase activity, cause a decrease in saturated fatty acids but a significant increase in cholesterol, unsaturated fatty acids of total phospholipids and 2, 4, 6-trinitrobenzenesulfonate binding to phosphatidylethanolamine as compared with the control cells. OK-432 administered for 2 days to AH 41 C cell-bearing rats also enhanced the leakage of the intracellular cations and the proportion of arachidonic acid in total phospholipids. On the other hand, significant alterations of these parameters in the cells were not demonstrated by 5FU and CP treatments. OK-432 treatment is considered to have an important influence on the lipid metabolism of the cells resulting in an increase in membrane fluidity which is related to leakage of essential components and hexokinase, consequently the leakage appears to inhibit the cell growth.

Effect of physical activity upon cholesterol synthesis in the rat liver

The effect of physical activity upon the synthesis of cholesterol and of fatty acids in rat liver was investigated. The serum cholesterol level, and cholesterol and fatty acids content in the liver was also determined. There was a significant increase of cholesterol and of fatty acid synthesis in the exercised rats as compared to the controls. There was no difference in the serum cholesterol level between the two groups studied. It is suggested, that the observed changes probably are due to an increased secretion of thyroid hormone. L'effet de l'activité physique sur la synthèse du cholestérol et des acides gras dans le foie de rat a été étudiée. Le niveau du cholestérol sérique et la teneur du foie en cholestérol et en acides gras ont été aussi dosés. La synthèse du cholestérol et des acides gras est augmentée de façon significative chez les rats exercés. Il n'y avait pas de différence quant au niveau du cholestérol sérique entre les deux groupes étudiés. Il est suggéré que les changements observés sont probablement dus à la sécrétion augmentée de l'hormone thyroïdienne. Die Wirkung der körperlichen Aktivität auf die Synthese von Cholesterin and Fettsäure in der Leber der Ratte wurde untersucht. Auch der Serumcholesterinspiegel und der Cholesterin- and Fettsäurengehalt der Leber wurde bestimmt. Es wurde ein signifikanter Anstieg der Cholesterin- and Fettsäurensynthese in den exerzierten Ratten gefunden, verglichen mit den Kontrolltieren. Es gab keinen Unterschied zwischen den zwei untersuchten Gruppen, was den Serumcholesterinspiegel betrifft. Es wird darauf hingewiesen, dass die observierten Veränderungen wahrscheinlich Folge sind einer vermehrten Sekretion von Schilddrüsenhormon.

The effect of short-term stress (tournament bridge playing and performance of surgery) on serum lipids

Summary Tournament bridge playing and surgery were used to study the effects of “stress” on normal people. The lipoprotein levels in blood were not altered significantly by 4 to 8 hours of such stress. Total cholesterol increased significantly after the performance of surgery and approached significance after bridge playing. However, control subjects, under no stress during a comparable period to that of the bridge playing, also showed a significant increase in cholesterol. There was little change in the mean triglyceride level, but in individuals, both bridge players and controls, elevation or depression of the triglyceride concentrations from the initial levels was observed; these changes were not related to stress. The results show that severe stress of 4 to 8 hours' duration need not be associated with changes in the levels of cholesterol, lipoproteins or triglycerides, and do not therefore support the concept that short-term stress necessarily contributes to atherogenesis by the mechanism of temporary serum lipid elevations. The possible longterm effects of nervous overactivity on lipid metabolism were not considered.