Effects of Dietary Amino Acids on Brain Amino Acids and Transmitter Amines in Rats with a Portacaval Shunt

The etiologic relationship between disturbances in metabolism of amino acids and amines and hepatic coma was investigated by examining the effects of diets containing various mixtures of amino acids on brain amine metabolism in rats with a portacaval shunt, using a method for simultaneous analysis of amino acids and amines. Rats with a portacaval shunt were fed on four different amino acid compositions with increased amounts of various amino acids suspected to be etiologically related to hepatic coma, such as methionine, phenylalanine, tyrosine, and tryptophan. The animals were killed 4 weeks after operation. During the experimental period, these animals did not become comatose, but exhibited various behavioral abnormalities. Marked increase in the plasma and brain levels of the augmented amino acids, especially methionine and tyrosine, were observed in rats with a portacaval shunt. Brain noradrenaline, dopamine, and serotonin levels were significantly decreased when the brain tyrosine level was increased. These results indicate that in rats with a portacaval shunt the dietary levels of amino acids greatly influence the brain levels of both amino acids and transmitter amines.     

Pumpkin (Cucurbita sp.) seed globulin VI. Proteolytic activities appearing in germinating cotyledons

N--benzoyl D,L-arginine p-nitroanilide (BAPA), leucine p-nitroanilide(LPA) and casein hydrolytic activities were assayed in germinatingcotyledons. BAPA hydrolytic activity was not detected in dryseeds, but increased rapidly from 1 to 4 days of germinationand then decreased. LPA and casein hydrolytic activities weredetected in dry seeds and increased from 2 to 4 days. Caseinhydrolytic activity decreased faster than the other two activities. BAPA hydrolytic enzyme was partially purified. It was inhibitedby p-chloromercuribenzoate and activated by ß-mercaptoethanoland dithiothreitol, but was not affected by EDTA, phenylmethylsulfonylfluoride, pumpkin trypsin inhibitor and several divalent cations.It had no ability to hydrolyze globulin or the chain to produce F_ß or smaller polypeptides,respectively, which was referred to as proteolytic activityI in the preceding paper (14), but released small peptides andamino acids from the chain and F_ß. However, it wasdifferent from proteolytic enzyme II which was present in dryseeds and inhibited by EDTA (14). Pumpkin trypsin inhibitor was purified. Its molecular weightwas estimated to be 10,500 by gel filtration. It did not inhibitthe BAPA hydrolytic enzyme. Both proteolytic activities I andII were also not reduced by the inhibitor (14). The inhibitoryactivity decreased gradually during germination. (Received November 9, 1979; )     

Ecological studies ofRoparidia fasciata in Okinawa island I. Distribution of single- and multiple-foundress colonies

To compare between a single-foundress colony and a multiple-foundress colony at the pre-emergence state of a social wasp, R. fasciata, nest distributions and colony terminations were investigated in 8 sites with different environmental conditions. Marking experiments were also conducted in two sites at high wasp density.

1. Foundress populations were composed of single-foundress colonies in sites C, D and E, new environments where have recently suited for inhaviting, at low wasp density. In sites like A and B which were used year after year, at high wasp density, coexistence of multiple-and single-foundress colonies was observed.
2. From the marking experiment, nests initiated by a single foundress were more distant away from the nest where the original foundress emerged the fall before, compared to multiple-foundress nests which were initiated by multiple foundress.
3. Greater percentage of colony termination was observed in single-foundress nests than in multiple-foundress nests, and the colony termination in single-foundress colonies increased with the nest density.
4. Ant predation was the key factor causing the variation of the percentage of colony termination.

     

Effect of glucose on protein phosphorylation in rat pancreatic islets

Isolated rat pancreatic islets, incubated in the presence of extracellular ³²Pi to steady state ³²P incorporation into cellular phosphopeptides, were exposed to glucose for 10 min. Glucose (16.7 mM) significantly stimulated the phosphorylation of six phosphoproteins with molecular weights of 15,000, 35,000, 49,000, 64,000, 93,000 and 138,000. Mannoheptulose (16.7 mM) markedly inhibited glucose-stimulated phosphorylation of these six phosphoproteins. This protein phosphorylation might be important in mediating glucose-stimulated insulin release.     

The nucleotide sequence of 5S ribosomal RNA from Schizosaccharomyces pombe

The nucleotide sequence of 5S rRNA from the fission yeast, S. pombe, has been established by post labeling procedures combined with cataloging RNase T1- and A-oligonucleotides derived from unlabeled 5S rRNA. The sequence consists of 119 nucleotides without a modified base and shows more dissimilarities (at 38 positions) from that of S. cerevisiae than from that of humans (at 33 positions).     

Biological effects of anti-idiotypic antibodies on lymphocyte function: I. Analysis of the effects on B lymphocytes of combining site and framework-directed anti-T-15 idiotypic antibodies

Anti-idiotypic antibodies against TEPC-15 myeloma protein (BALB/c origin) were raised in allogeneic animals by immunization of A/J mice with the myeloma protein. The antibody activities were fractionated into two specificities by TEPC-15 immunoadsorbent affinity columns by elution with free hapten (phosphorylcholine, PC), followed by elution with acidic buffer (glycine- HCl, pH 2.3). Idiotype binding analysis indicated that the fraction eluted with hapten could be inhibited in its binding to TEPC-15 by free hapten (i.e., binding site-directed anti-idiotypic antibody), whereas the acid-eluted fraction could not (i.e., framework-directed anti-idiotypic antibody). When analyzed for their biological activities on PC-specific B lymphocytes producing T-15 idiotype-bearing antibodies, both anti-idiotypic antibody fractions had similar suppressive effects on the in vitro production of antiphosphorylcholine antibody in culture.     

Inhibitory effects of condiments and herbal drugs on the growth and toxin production of toxigenic fungi

The effects of thirteen kinds of powdered herbal drugs and seven kinds of commercial dry condiments on the growth and toxin production ofAspergillus parasiticus, A. flavus,A. ochraceus, andA. versicolor were observed by introducing these substances into culture media for mycotoxin production.Of the twenty samples tested, cinnamon bark completely inhibited the fungal growth, while the others only inhibited the toxin production.The inhibitors were easily extracted from the samples with solvents such as hot water, chloroform, or ethanol.The extracts from coptis, philodendron bark, mustard, green tea leaves, and zanthoxylum completely inhibited the aflatoxin production ofA. parasiticus, however, they had little or no inhibitory effect againstA. flavus.     

Pumpkin (Cucurbita sp.) seed globulin I. Purification, characterization, and subunit structure

A heat stable globulin present in the cotyledons of pumpkinseeds was prepared as crystals which were soluble in a dilutesaline solution below pH 4.5 or in a solution with a high ionicstrength at neutral pHs. The protein was nearly homogeneousby ultracentrifuge analysis, and had a molecular weight of about112,000 daltons. Sodium dodecyl sulfate-polyacrylamide gel electrophoresisseparated the globulin into two subunits, and ß,corresponding to molecular weights of about 63,000 and 56,000daltons, respectively. By reduction of disulfide bonds, thetwo subunits were each separated into two polypeptide chainswith molecular weights of around 36,000 and 22,000 daltons,judged by gel electrophoresis. The amino acid composition ofwhole globulin indicated high contents of arginine, glutamicacid and aspartic acid. The total number of half-cystine residuewas nine and only one residue was shown to be free. The subunitstructure of the globulin is discussed. The protein has beenshown to have oxaloacetate decarboxylase activity, and thisfact was confirmed. However, the activity decreased markedlyat pH 4.5 in a fairly short period. It did not require Mn⁺⁺,and the K_m for oxaloacetate was determined to be 4.1 mM. (Received April 9, 1976; )     

An endo-(1→6-β-D-glucanase from Mucor hiemalis

An endo-(1→6)-β-D-glucanase (EC 3.2.1), isolated from the culture filtrate of Mucor hiemalis, was purified by ammonium sulphate fractionation and gel filtration. The homogeneity of the enzyme was confirmed by disc electrophoresis. The enzyme had a wide range of temperature and pH stability, high substrate specificity, and an action pattern of the endo-type.