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Biomedical subjects

S Takeda

Publications and source records attributed to S Takeda.

At least 865 records · Page 48Linked to original sources

[A device for the drug-capsule administration into the rat stomach and its pharmacological application (author's transl)].

To assess the absorption of drugs given in capsule form to rats, the method of administration was studied using gastric-cannulated rats. The body weight of these rats remained the same as even when given casein hydrolysate and vitamins in addition to the usual chow diet. Indomethacin (IM) capsule (2 mg/capsule) was given and the plasma concentration and anti-inflammatory action of IM were studied. The maximum plasma concentration was seen at 2 hr after administration of one capsule. The carrageenin-induced edema of rat hind paw was inhibited with the ingestion of only one capsule. In addition, the time course of the plasma concentration of IM correlated with that of the inhibitory effect of carrageenin-induced edema. In the case of administration of a barium sulfate capsule to the cannulated rats, the transfer of the barium sulfate was clearly observed on the X-rays. Our findings suggest that this approach to the estimation of drugs is feasible, at least in experimental animals.

Animals↗

Study of agglutination of mouse mammary carcinoma (FM3A) cell induced by egg agglutinin of Rana catesbiana. II. Phytohemagglutinin P and protamine.

When mouse mammary carcinoma (FM3A) cells were treated with egg agglutinin of Rana catesbiana for 15 min at 25 degrees C, percent total particle number of both cell aggregates and single cells was in direct proportion to the cell electrophoretic mobility. Phytohemagglutinin P mediated agglutination proceeded with biphasic kinetics: the higher the concentration of phytohemagglutinin P the shorter was the lag period between the first and second stages of agglutination. In protamine-mediated agglutination, the percent total particle number was reduced at low concentrations, while the electrophoretic mobility reduced only at high concentrations. Agglutinating and cytotoxic activities of these three reagents were in an intimate relation: the higher the agglutinating activity, the greater was their cytotoxic activity.

Agglutination↗

Antigenicities of stem bromelain. Contribution of three-dimensional structure and individual amino acid residues.

The contribution of three-dimensional structure and individual amino acid residues to the antigenicities of macromolecular protein was investigated for a thiol protease stem bromelain as antigen. The extent of the participation was demonstrated by a decrease in antigenicity when the enzyme was denatured in 8 M urea before and after reductive cleavage of intrapeptide disulfide bonds or modified in particular amino acid residues. The results showed that the enzyme treated with 8 M urea without reductive cleavage of disulfide bonds preserved about 90% of antigenicity to antibodies against native stem bromelain, while the enzyme denatured after the reductive cleavage of disulfide bonds brought about almost 80% disappearance of the antigenicity. Modification of individual amino acid side chains revealed that lysine was the most immunodominant amino acid, showing 2.5% contribution per residue, and tyrosine followed with 1.2%. However, acidic amino acids such as flutamic and aspartic acids were found to be as low as 0.3%, and tryptophan was 0.2%. These data suggest that most of the antigenic determinants of stem bromelain are of the steric conformation in which lysine and/or tyrosine are most frequently involved as immunodominant amino acids.

Amino Acids↗

Pharmacological studies of gardenia fruit. V. Mechanisms of inhibitory effect of genipin on gastric acid secretion and its facilitatory effect on bile secretion in rats.

In the experiment on continuous perfusion of rat stomach in vivo, genipin inhibited only the gastric acid secretion induced by carbachol, but not by tetragastrin, or histamine. In the experiment on isolated organs, genipin showed a weak competitive anti-acetylcholine action on the intestinal contraction. Based on these facts and results reported previously, it is conceivable that anti-cholinergic action at least partly contributes to the genipin-induced inhibitory effect on gastric functions. Erythritol clearance was increased with the increase in bile flow by administration of genipin. Genipin showed a significant choleretic action, and just then the concentration of biliary bile acid was decreased inversely. In the relationship between bile flow and biliary bile acid excretion rate, the slope of regression line obtained from genipin-treated group was not significantly different from that of control, and these lines were approximately parallel to each other. Genipin did not affect the concentration of sodium, potassium, chloride, or bicarbonate in the bile collected during the initial stage, in which bile flow was increased, after administration. It is concluded from these results that genipin-induced choleretic action proceeds by a mechanism wherein water is driven along osmotic gradient which originates in the transport of bile acid-independent fraction from hepatocytes into canaliculi, mainly through active Na+ transport.

Animals↗

Pharmacological studies on iridoid compounds. II. Relationship between structures and choleretic actions of iridoid compound.

The relationship between the structures and the choleretic actions of iridoid compounds was examined. Only patrinoside and villoside accelerated bile secretion among the iridoid glucosides but all of the iridoid aglycones increased it after intravenous administration rats. The choleretic effects of villoside, patrinoside aglycone, and 11-deoxy patrinoside aglycone were far weaker in comparison with those of other active iridoid compounds. When an equimolar amount of patrinoside, its aglycone, or 11-deoxy patrinoside aglycone was administered intravenously, their periodical patterns of choleretic activities nearly paralleled with those of isovaleric acid excreted in the bile. Patrinoside was partly hydrolyzed into its aglycone by the artificial gastric juice or the intestinal content. After intraduodenal administration of patrinoside (1 g/kg), the amount of patrinoside enough to exert a choleretic action was detected in the portal blood. These findings indicate that the hemiacetal moiety of iridoid compounds plays an important role in exerting a strong choleretic action and that patrinoside shows the same action following saponification of isovalerate of C-1 position in the liver.

Animals↗

Neuropathological comparative studies on experimental allergic neuritis (EAN) induced in rabbits by P2 protein-ganglioside complexes.

The light microscopical examinations were performed on the peripheral nerve (PN) lesions in rabbits induced by bovine peripheral nerve (BPN) myelin and by its components. Morphology of the PN lesions induced by P2 protein-ganglioside complex were equivalent to those induced by PN myelin (original EAN); and some of them were more remarkable in severity than the original EAN. The lesions were composed of myelin destruction, numerous macrophages containing myelin debris, completely demyelinated axons and remyelinating fibers. P2-I, acid treated P2-I and P2-II proteins induced PN lesions. Histologically they were moderate to minimal in severity in that order. However, when each protein was injected as the complex with ganglioside, PN lesions obviously became severer, respectively. These findings indicate the possibility that the P2-ganglioside complex may be involved in the chemical principle of EAN, and also the findings strongly support the theory proposed by Nagai et al. that gangliosides may play an essential role in rabbit EAN to give P2 protein a special conformation necessary for antigenic activity.

Animals↗

Metabolism, antitumor activity, and acute toxicity of 5-fluoro-1,3-bis(tetrahydro-2-furanyl)-2,4-pyrimidinedione by oral administration to animals.

The metabolism, antitumor activity, and acute toxicity of 5-fluoro-1,3-bis-(tetrahydro-2-furanyl)-2,4-pyrimidinedione (FD-1) were investigated in animals, compared with 5-fluoro-1-(tetrahydro-2-furanyl)-2,4-pyrimidinedione (FT). It was found that after oral administration of FD-1, the level of 5-fluorouracil (5-FU) was maintained higher and longer than after administration of FT, and that a large amount of 5-FU was released from FD-1 by liver microsomal drug-metabolizing enzymes or spontaneous hydrolysis via 5-fluoro-3-(tetrahydro-2-furanyl)-2,4-pyrimidinedione (3-FT) and FT. FD-1 had a significant activity against the solid form of Ehrlich carcinoma, sarcoma-180, hepatoma AH130, Yoshida sarcoma, Walker carcinosarcoma-256, and leukemia L1210 and P388, but not the ascitic forms, and it produced greater inhibition of tumor growth than FT. The acute toxicity of FD-1 was less than that of FT.

Administration, Oral↗