We evaluated the effect of vitamin E on the growth of cultured bovine aortic endothelial cells (BAEC). A high concentration of glucose (≥200mg/dl) in the culture medium reduced the replication of BAEC. Addition of vitamin E at a physiological concentration of 6μg/ml restored the impaired replication of BAEC cultured with a high concentration of glucose. Vitamin E had no effect on the growth of BAEC cultured with 100mg/dl glucose. Proliferation of BAEC was not significantly affected by exposure to mannitol at levels equimolar with a high concentration of glucose (600mg/dl), indicating that a high osmolality was not related to the glucose-induced reduction of replication of the cells. BAEC cultured in a high glucose medium may be susceptible to oxidative stress, and the benefit effect of vitamin E may be partly due to a reduction in oxidative damage. Vitamin E may protect endothelial cells against glucose-induced injury.
Oral submucous fibrosis is a chronic disease of obscure etiology affecting the oral cavity. Several histologic and epidemiologic studies on this condition have been conducted, but the biochemical aspects have not yet been thoroughly explored. Hence the present study was undertaken to study the hematological status and trace elements in this condition. There was no change in the cell count, whereas increases in platelet count, eosinophil number, and erythrocyte sedimentation rate were observed. There was a significant decrease in the levels of hemoglobin, iron, ceruloplasmin, copper and zinc; and they correlated well with the progression of the disease. Consideration of these findings should open new avenues for exploration of the disease from new perspectives.
Alterations in liver microsomal drug-metabolizing enzymes and phospholipids following oral administration of chloroquine to rats for 14 days were investigated. An increase in cytochrome P450 and cytochrome b5 contents and an increase in the activities of NADPH cytochrome c reductase and NADH microsomal cytochrome reductase were observed. A decrease in cholesterol and an increase in phospholipids were noted in the microsomal membranes, which altered the membrane fluidity, which may be of importance in controlling different membrane functions. The increase in different fractions of microsomal phospholipid is probably due to an increased incorporation of acetate into phospholipids.
Our previous study demonstrated that reticuloendothelial system function can be monitored by in vivo clearance of chondroitin sulfate iron colloid [Ishida, H. et al. (1991): J. Biochem. Biophys. Methods; Ishida, H. et al (1992): J. Biochem. Biophys. Methods; Tsujinaka, T. et al. (1993): JPEN]. In the present study hepatic clearance of radiolabeled chondroitin sulfate iron colloid (CS59Fe) was investigated in detail. When administered intravenously, CS59Fe was taken up by not only Kupffer cells but also liver endothelial cells and liver parenchymal cells. Radioactivity per 106 cells was highest in Kupffer cells. When binding of CS59Fe to isolated liver cells was examined at 4°C, the association of CS59Fe showed a good linearity on a double-reciprocal plot, giving Nr (number of receptors) and Kp (membrane-particle constant). Nr was greatest of all for Kupffer cells. When CS59Fe was pretreated with plasma, the Nr increased and Kp decreased in Kupffer cells and liver endothelial cells, whereas Kp increased in liver parenchymal cells. However, no influence was found as a result of pre-treatment of CS59Fe with fibronectin or heated plasma. The addition of mannan had no effect. This in vitro chondroitin sulfate iron colloid binding assay may be useful to evaluate effects of various mediators on phagocytosis of hepatic cells.
We previously reported that the feeding of the safflower oil diet results in lower acetyl-CoA carboxylase activity in the liver compared with the feeding of a beef tallow diet. We also suggested that sympathetic activity (norepinephrine turnover rate and α1-adrenergic receptor binding) in the liver was higher in the safflower oil diet group. In order to confirm the effect of dietary fats consisting of different fatty acids on the hepatic acetyl-CoA carboxylase activity related to sympathetic activity, we chemically sympathectomized rats by treating them with 6-hydroxydopamine. The sympathectomized rats and control rats were then meal-fed a safflower oil diet or a beef tallow diet for 8 weeks. Sympathectomy abolished the difference in acetyl-CoA carboxylase activity in the liver between the two dietary groups. The percentage of body fat was increased by sympathectomy, resulting in no difference between the safflower oil diet group and the beef tallow diet group. These results support the hypothesis that, the intake of a safflower oil diet decreases hepatic acetyl-CoA carboxylase activity by increasing the sympathetic activity.
In the serum from patients with certain neurological diseases, antibodies against GM1 ganglioside are detected in high titers, suggesting that these antibodies may be involved in the pathological process. In this present study the liposome immune lysis assay was applied to determine anti-ganglioside antibodies in serum, and the results were compared with those of the commonly used enzyme-linked immunosorbent assay, where gangliosides are fixed on a solid surface. This liposome method is based on the measurement of a fluorescent dye released from liposomes by complement-mediated immune lysis. The value of the specific release of a fluorescent dye from liposomes by the serum from normal control individuals was used as a criterion to evaluate the antibody level. The values of the specific marker release from liposomes by anti-GM1 antibodies were scarcely correlated with the titers of IgM or IgG antibodies measured by the enzyme-linked immunosorbent assay, suggesting that the nature of anti-GM1 antibodies detected by the two assay methods may be different. The antibodies detected by the liposome immune lysis assay may represent those involved in membrane lysis, which occurs in the pathogenesis of some neurological diseases.
We have developed a sensitive immunoprecipitation (IP) assay that uses anti-Torpedo californica (Tc) acetylcholine receptor (AChR) antibody for measuring anti-AChR antibodies in sera from patients with myasthenia gravis (MG). With this assay, we simultaneously detected two types of anti-AChR antibodies in MG sera: enhancing-type antibodies that accelerate the binding of anti-Tc AChR antibody to human AChR and blocking-type antibodies that inhibit the binding of α-bungarotoxin to AChR. Antibodies were detected in 80% of the MG sera, 45% being the enhancing- and 35% the blocking-type antibodies. The inhibitory activities of these blocking-type antibodies correlated well with the titers of blocking-type antibodies obtained by the Concanavalin A assay. The titers of the enhancing-type antibodies also were correlated with those of non-blocking-type antibodies ass measured by the standard IP assay.