Fumiyo Sako

Human blood group glycosphingolipids of porcine erythrocytes

Two glycosphingolipids with human blood group A and H antigenicity were isolated from porcine erythrocyte membranes which were obtained from the pooled blood. The yield of the A- and H-antigenic glycolipids was approximately 0.2 and 0.1% of total neutral glycolipids, respectively. No B antigen was detected. Through several methods the porcine erythrocyte antigens were all found to belong to lactoseries (type 1 chain), IV2Fuc alpha, IV3GalNAc alpha Lc4Cer for type A and IV2-Fuc alpha Lc4Cer for type H, in contrast to the antigenic glycolipids in human erythrocytes, which mostly belong to neolactoseries (type 2 chain). The constituent fatty acids of the A antigen were 75% normal acids and 25% 2-hydroxy acids, and the long chain base was 95% sphingenine. This is the first demonstration of the A- and H-antigenic glycolipids on erythrocytes of pig in whose gastric mucin the human blood group A and H substances have been demonstrated.

Cytotoxicity of food dyes on cultured fetal rat hepatocytes

Abstract The cytotoxicity of 11 dyes, used as food dyes in Japan, on cultured fetal rat hepatocytes was studied. Xanthene dyes containing halogen atoms in their molecules such as phloxin, rose bengal, and erythrosine were more toxic than other groups of food dyes. In the present paper the effect of food dyes on the cell growth of hepatocytes was also examined. Phloxin was especially toxic to the cell growth and a dose-response relation was observed between the concentration of phloxin and the cell growth of hepatocytes when the dye was added 3 days after plating.

Effects of food dyes on Paramecium caudatum: Toxicity and inhibitory effects on leucine aminopeptidase and acid phosphatase activity

Abstract The toxic effect of 14 food dyes was studied in Paramecium caudatum . It was found that xanthene dyes containing halogen atoms in their molecules were more toxic than other groups of food dyes. Phloxin and rose bengal containing chlorine were especially toxic. The effect of food dyes on leucine aminopeptidase, acid phosphatase, and γ-glutamyl transpeptidase activity in P. caudatum was studied in order to investigate the mechanism of toxicity. Phloxin and rose bengal inhibited leucine aminopeptidase remarkably. The inhibitory effect of food dyes on leucine aminopeptidase in vitro is consistent with the toxic effect of the dyes on the survival time of P. caudatum . A possible correlation between toxicity and inhibition of the activity of enzymes involved in the digestive process is discussed.

Human blood group A and H glycolipids in porcine plasma: Evidence for acquisition of the erythrocyte antigens from plasma

Human blood group A‐ and H‐antigenic glycosphingolipids were isolated from pooled porcine plasma. The structures of the A‐active hexa‐ and H‐active pentaglycosylceramides of lactoseries (type 1 sugar chain) were the same as those in porcine erythrocytes. These results endorse biochemically the previous observations that the A and H antigens on porcine erythrocytes are taken up from plasma.

Induction of γ-glutamyl transpeptidase and glutathione S-transferase in cultured fetal rat hepatocytes by laccaic acid and monascus pigments

The cytotoxicity of 8 natural dyes, commercially available as food additives in Japan, was studied on cultured fetal rat hepatocytes. Laccaic acid, one of the carminic acid samples and monascus pigments were found to be very toxic to cultured hepatocytes. Laccaic acid caused an increase in gamma-glutamyl transpeptidase activity. An 11-fold increase was seen 4 days after such addition, a significantly greater elevation than that produced by either the water or acetone solvents employed, or other dyes which have no toxic effects. On the other hand, monascus pigments had an increasing effect on both gamma-glutamyl transpeptidase and glutathione S-transferase, the later enzyme being elevated approximately 9 times greater than control values within 2-4 days. The increases in gamma-glutamyl transpeptidase and glutathione S-transferase activities by laccaic acid and monascus pigments could be inhibited by the simultaneous addition of either actinomycin D or cycloheximide. This suggests that the induction of these enzymes requires transcription and translation processes.

Characterization of neutral glycosphingolipids from porcine erythrocyte membranes.

1. Six neutral GSL fractions were purified from porcine erythrocyte membranes. 2. They were identified to be LacCer (14% of total neutral GSLs), 2-hydroxy acid-rich and -poor Gb3Cer (3 and 7%, respectively) and Gb4Cer (71%) by means of NMR spectrometry. 3. Monohexosylceramides (5%) were composed of GlcCer and GalCer with near amount. 4. All these GSL classes contained a high concentration (more than 20% of total acids in each class) of 2-hydroxy fatty acids. 5. GalCer and GlcCer contained considerable amounts of C16- and C18-acids, and of C18-phytosphingosine, whereas C24-acids and C18-sphingosine were predominant in the other GSLs. 6. A minor GSL fraction (less than 1% of total neutral GSLs) which migrated more slowly than Gb5Cer on a thin layer plate and composed of several GSL components contained L-fucose.

Characterization of acidic glycolipids in porcine plasma

Acidic glycosphingolipids including two sulfatides and five gangliosides were isolated from porcine plasma. They were characterized by NMR spectrometry as galactosylceramide-I3-sulfate and lactosylceramide-II3-sulfate, gangliosides GM3, GD3, GM1, GD1a and fucosyl GM1.