PubMed Health⌕ Search

Biomedical subjects

H Fujimura

Publications and source records attributed to H Fujimura.

At least 199 records · Page 11Linked to original sources
PubMed1985

Interaction of BW755C, a potent inhibitor of lipoxygenase and cyclo-oxygenase, with mitochondrial cytochrome oxidase.

The interaction between BW755C (3-amino-1-[m-(trifluoromethyl)phenyl]-2-pyrazoline), a potent inhibitor of both lipoxygenase and cyclo-oxygenase, and respiratory chain in mitochondria and electron transport particles (ETP) from rat livers was examined. BW755C accelerated the oxygen uptake by mitochondria without the addition of substrate for the respiratory chain. Spectrophotometric study revealed that BW755C was quickly oxidized by cytochrome oxidase in mitochondria to a compound possessing an absorption maximum at 524 nm. p-Phenylenediamine (p-diaminobenzene, PPDA), which, like BW755C, serves as an electron donor to cytochrome oxidase, was shown to inhibit the generation of active oxygen in macrophages; the inhibition was stronger than that of BW755C. These results strongly suggest that the oxidative conversion of BW755C by mitochondrial cytochrome oxidase is associated with its potentially inhibitory action on the active oxygen-generating system in phagocytes.

4,5-Dihydro-1-(3-(trifluoromethyl)phenyl)-1H-pyraz↗
PubMed1985

Cholagogic effect of ginger and its active constituents.

The effect of bile secretion in rats was examined in order to clarify the stomachic action of ginger and also to investigate its active constituents. The results showed that mainly the acetone extracts of ginger, which contain essential oils and pungent principles, caused an increase in the bile secretion. Further analyses for the active constituents of the acetone extracts through column chromatography indicated that [6]-gingerol and [10]-gingerol, which are the pungent principles, are mainly responsible for the cholagogic effect of ginger.

Animals↗
PubMed1985

Novel nonnarcotic analgesics with an improved therapeutic ratio. Structure-activity relationships of 8-(methylthio)- and 8-(acylthio)-1,2,3,4,5,6-hexahydro-2,6-methano-3-benzazocines.

Conversion of the 8-phenolic 1,2,3,4,5,6-hexahydro-2,6-methano-3-benzazocines to the corresponding 8-thiophenolic analogues was achieved by three different routes. Diazotization of 8-amino-2,6-methano-3-benzazocine (2) followed by the reaction with CH3SNa afforded 8-(methylthio)-1,2,3,4,5,6-hexahydro-2,6-methano-3-benzazocine (3). Another route using Grewe cyclization was also examined for the synthesis of 3. As the most effective route, Newman-Kwart rearrangement of benzazocines was selected and closely investigated. 8-(N,N-Dimethylthiocarbamoyl)oxy derivatives (6a-e) rearranged to 8-(N,N-dimethylcarbamoyl)thio derivatives (7a-e) in good yields. Reductive cleavage of 7a-e and subsequent methylation or acylations gave the title compounds (3, 8-24). Although analgesic activities of sulfur-containing benzazocines decreased compared to the corresponding hydroxy compounds, the N-methyl derivative (S-metazocine, 8) showed potent analgesic activity.

Acylation↗
PubMed1985

Possible involvement of beta 2-adrenoceptors in hyperthermic effect of l-ephedrine in rats.

The experiments were conducted in order to examine the mechanism of hyperthermia induced by l-ephedrine in rats. beta-Adrenoceptor agonists have been known to enhance normal body temperature. Therefore, the effect of various beta-adrenoceptor agonists on body temperature in rats was examined to clarify the mechanism of action of l-ephedrine. The results showed that drugs with beta 2-adrenoceptor agonist activity and l-ephedrine caused hyperthermia in rats and this effect was selectively inhibited by pretreatment of animals with propranolol (a mixed beta-adrenoceptor antagonist) or butoxamine (a selective beta 2-adrenoceptor antagonist). These results suggest that hyperthermic action of l-ephedrine may largely be due to its effect on beta-adrenoceptors.

Albuterol↗
PubMed1985

Effects of butorphanol and its metabolites on the levels of monoamines and their metabolites in the rat brain.

The effects of butorphanol and its main metabolites, norbutorphanol and hydroxybutorphanol, on the contents of monoamines and their metabolites in various regions of the rat brain were compared with those of morphine and pentazocine using the HPLC-ECD method. The administrations of morphine and pentazocine increased dopamine turnover in the striatum and hypothalamus in a drug dose-dependent manner. The stimulative effects of butorphanol on the dopamine system were weaker than those of morphine and pentazocine, and there were no dose-dependencies in these effects of butorphanol. Butorphanol, morphine and pentazocine increased 5-HT turnover, but there was no drug dose-dependent effect in the case of butorphanol. These differences for the effects of butorphanol from those of morphine and pentazocine seemed to result from the antagonist-agonist property of butorphanol and from a different manner of interaction with the opioid receptor. The effects of butorphanol on the levels of the norepinephrine system were weak. It was considered that the effects of butorphanol on monoamine turnover were produced by the action of butorphanol itself, because norbutorphanol and hydroxybutorphanol showed little change on the level of monoamines and their metabolites.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1985

Cephem antibiotics and alcohol metabolism.

Mechanisms of the disulfiram-like reaction of cephem antibiotics were studied. Changes in ethanol (EtOH) and acetaldehyde (AcH) levels in the blood with EtOH loading following daily intravenous administration of cephem antibiotics were determined in rats and the following were found: The daily intravenous injection of cefazolin, cefotiam (CTM), cefsulodin, cefoxitin or ceftizoxime in no way varied the changes in the EtOH and AcH levels in the blood with EtOH loading. The daily intravenous injection of cefmetazole, cefoperazone, cefamandole, latamoxef, cefmenoxime or cefotetan caused the AcH level in the blood to be elevated significantly until at least 8 hours after the EtOH loading, but was inert on the EtOH level on the blood. The daily administration of 1-methyl-2-tetrazoline-5-thione (TZ), a compound having a partial structure similar to those of the cephem antibiotics elevating the AcH level in the blood on EtOH loading, was inert on the EtOH level in the blood but elevated the AcH level in the blood. The daily administration of 1-(2-dimethylaminoethyl)-2-tetrazoline-5-thione (MTZ), a compound having a partial structure similar to that of CTM, was inert either on the EtOH or AcH level in the blood. The cephem antibiotics elevating the AcH level in the blood all had a (1-methyl-1H-tetrazol-5-yl) thiomethyl group in the 3 position of the aminocephalosporanic acid nucleus. It was though that the disulfiram-like reaction caused by the cephem antibiotics was derived from the elevation of AcH level in the blood.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetaldehyde↗
PubMed1985

[Antitumor effect of OK-432 (3)--mechanisms of tumor growth inhibition by OK-432 induced activated macrophages].

Spleen cells and peritoneal exudate cells obtained from BALB/c mice which had received an i.p. injection of 0.1 mg of OK-432 4 days previous to sacrifice, were examined by Winn's neutralization assay for their antitumor activity against Meth-A sarcoma cells in BALB/c mice. Both of the cell preparations clearly inhibited the growth of admixed Meth-A cells, but when these same cell populations were treated on a Sephadex G-10 column, the effector activity seen in Winn's assay disappeared. The effector cells responsible for tumor inhibition were therefore considered to be cytotoxic macrophages. However, the inhibitory effect of these cytotoxic macrophages in Winn's assay was not evident in either X ray (300 rad)-irradiated BALB/c mice or in nu/nu BALB/c mice. These results indicate that the antitumor activity of cytotoxic macrophages is associated with a sequential immune mechanism in which T cells may play an important role.

Animals↗
PubMed1984

The effect of clidanac, a potent anti-inflammatory drug, on mitochondrial respiration: a consideration on the uncoupling activity of optical enantiomers.

The uncoupling activities of clidanac and its dechlorinated derivative on oxidative phosphorylation were examined using isolated rat liver mitochondria. Clidanac was found to uncouple the oxidative phosphorylation and no difference was detected in the uncoupling potency of the two enantiomorphs. Dechlorclidanac was significantly less effective in the uncoupling activity than clidanac.

Animals↗
PubMed1984

[The effects of various drugs on the binding site of bilirubin in serum albumin].

In the presence of various drugs, the concentration of free bilirubin which was released from the first binding site of bilirubin in serum albumin was evaluated, using a sensitive method based on static fluorescence quenching of dansyl serum albumin. Bilirubin bound to human serum albumin more strongly than to bovine serum albumin. Non-steroidal anti-inflammatory drugs, fenamates and allylphenyl propionic acids, affected the bilirubin-serum albumin interaction. Flufenamic acid and ketoprofen released bilirubin from human serum albumin. The bilirubin bound to the serum albumin was not influenced by the presence of indomethacin, but clidanac strongly dissociated bilirubin from the bilirubin-serum albumin complex. Sulfa-drugs, antibiotics, steroidal agents, warfarine, tolubutamide and phenytoin showed no significant effects on the bilirubin-serum albumin interaction. The fluorescence quenching method may be useful to evaluate the interaction of drug-bilirubin-serum albumin.

Animals↗