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Biomedical subjects

T Satoh

Publications and source records attributed to T Satoh.

At least 1,333 records · Page 74Linked to original sources
PubMed1978

Comparison of effects of acetaminophen on liver microsomal drug metabolism and lipid peroxidation in rats and mice.

Studies were conducted to determine the in vivo effect of acetaminophen (AAP) on the lipid peroxidation, drug metabolizing enzyme activity and microsomal electron transfer system of rat and mouse liver. AAP was found to inhibit ethylmorphine N-demethylase activity in the presence of NADPH and this inhibition of the enzyme was due to decrease in cytochrome P-450 content, but not due to change in lipid peroxidation in liver microsomes. Kinetical data showed that AAP administration had no effect on Km values of ethylmorphine N-demethylase, however, a decrease in the Vmax values was seen in rats and mice. There was no significant effect of AAP on both NADPH-cytochrome c reductase and the content of cytochrome b5 3 hours after this administration to rats and mice. On the other hand, AAP induced a significant decrease in NADH-ferricyanide reductase in mice, but not in rats. The greatest decrease in cytochrome P-450 observed among the components of the liver microsomal electron transfer system of rats and mice.

Acetaminophen↗
PubMed1978

Glutathione depletion by aniline analogs in vitro associated with liver microsomal cytochrome P-450.

Enzymic depletion of glutathione (GSH) in vitro by aniline analogs was mostly dependent on the cytochrome P-450 level in liver microsomes. In a case of acetaminophen (AAP), active metabolite of AAP formed through liver microsomal drug metabolizing enzymes consumed GSH. The active metabolite formed binds, at least in part, covalently to liver microsomal proteins. In addition, species differences in the extent of GSH depletion by AAP in vitro was related to the amounts of the active metabolite of AAP bound covalently to liver microsomal protein(s) by experiments using 14C-AAP. Similar depletion of GSH was also seen with other aniline analogs such as aniline itself and p-chloroaniline, but not with acetanilide, in four animal species. These in vitro results obtained here strongly support the well-known findings concerning both GSH depletion and covalent binding in vivo of the active metabolite after AAP treatment.

Acetaminophen↗
PubMed1977

Light-activated, -inhibited and -independent denitrification by a denitrifying phototrophic bacterium.

Effects of illumination on denitrification by a freshly isolated denitrifying phototrophic bacterium were investigated. Denitrification activity was induced when cells were grown in either light or darkness in the presence of nitrate without oxygen. Denitrification of nitrate with malate as the electron donor by cells at a phase of exponential growth occurred independently of illumination while that by cells in a stationary phase was activated. Effects of illumination on denitrification varied with electron donors. Using malate or succinate, denitrification by cells in a stationary phase was accelerated by illumination, inhibited when glucose or lactate was used, and independent of illumination when pyruvate was used. Denitrification by cells in an exponential phase was independent of illumination when succinate, malate or pyruvate was used and inhibited by it when glucose or lactate was used. Effects of illumination on the denitrification of nitrite were similar to those involving nitrate. Effects of various inhibitors on denitrification were examined in light-succinate and dark-lactate systems. Differences between the two systems are discussed.

Aerobiosis↗
PubMed1977

Effect of pretreatment with tricresylphosphates and phenobarbital on the metabolism and toxicity of procaine in rats.

We examined the effects of pretreatment with phenobarbital and tricresylphosphates, TOCP and TCP, on the metabolism and toxicity of procaine in rats. A single administration of procaine at a dose of 250 mg/kg intraperitoneally to adult rats caused convulsion, however, phenobarbital (80 mg/kg intraperitoneally daily, 4 days) pretreatment protected against the toxicity or procaine. In contrast, pretreatment of rats with TOCP (10 mg/kg per os) or TCP (10 mg/kg per os) revealed a higher incidence of toxicity as compared to control rats. Mortality in procaine-treated rats was significantly decreased with phenobarbital-pretreatment and, conversely, increased with TOCP and TCP. Paralysis, convulsion and death were induced at the brain level of procaine of 0.303 +/- 0.025, 0.480 +/- 0.026 and 0.565 +/- 0.018 mumole/g brain wet weight, respectively. Toxic effects of procaine were, therefore, concluded to be due to the accumulation of the drug in the brain.

4-Aminobenzoic Acid↗
PubMed1977

The pharmacokinetics of ochratoxin A in rats.

The absorption and tissue distribution of ochratoxin A (OCT A) following a single oral dose of OCT A were investigated in adult, male Wistar rats. In experiments concerning excretory patterns of OCT A, 14C-OCT A was used. A relatively large amount of OCT A was found in the circulating blood 48 hours after dosing. The patterns of absorption, tissue distribution and excretion of OCT A were affected by acute catarrhal enteritis produced by OCT A and/or ochratoxin alpha(OCT alpha). Quantitative data show that OCT A is distributed mostly in the kidney and this finding is closely associated with the tissue specifity of OCT A-induced nephrotoxicity. OCT A was found to be hydrolyzed to its major metabolite, OCT alpha by addition of the homogenate of pancreas, duodenum and ileum. Approximately 56% of OCT A administered was excreted in both urine and feces as the unchanged toxin and OCT alpha during 120 hours following dosing. A relatively larger amount of OCT alpha was detected as compared with that of OCT A.

Animals↗
PubMed1976

Rhodopseudomonas sphaeroides forma sp. denitrificans, a denitrifying strain as a subspecies of Rhodopseudomonas sphaeroides.

From polluted water of a lagoon pond a new type of denitrifying photosynthetic purple bacteria was isolated. With respect to morphology, fine structure, photopigments, requirement for growth factors, the range of utilization of organic substrates for phototrophic growth and DNA base ratio, the denitrifying strains show the closest resemblance to Rhodopseudomonas sphaeroides and were therefore described as a subspecies named R. sphaeroides forma sp. denitrificans. The new isolates grow well with nitrate anaerobically in the dark accompanying the evolution of nitrogen gas. They cannot assimilate nitrate as the nitrogen source for growth.

Aerobiosis↗