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Biomedical subjects

H Okuda

Publications and source records attributed to H Okuda.

At least 487 records · Page 27Linked to original sources

Aminopeptidases and arylamidases in normal and cancer tissues in humans.

Multiforms of aminopeptidases and arylamidases in normal human liver, stomach, lung, ileum, colon, rectum, and kidney, and cancer tissue from human liver, stomach, and lung were separated by triethylaminoethyl cellulose column chromatography. The aminopeptidases and arylamidases were solubilized from human tissues by treatment with bromelain, and their column chromatograms on triethylaminoethyl-cellulose gave different patterns of multiforms of enzymes in these tissues. The fractions of enzymes separated specificities toward L-leucyl-beta-naphthylamide, L-leucinamide, L-methioninamide, L-phenylalaninamide, and L-alaninamide. The activity of aminopeptidase toward L-leucinamide and of arylamidase toward L-leucyl-beta-naphthylamide was higher in human stomach cancer tissue and lower in hepatic cancer tissue than in normal stomach and liver, respectively. In lung cancer tissue, the activity of aminopeptidase toward L-leucinamide was abnormally low, while the activity of arylamidase toward L-leucyl-beta-napthylamide was similar to that in normal lung. The substrate specificities or patterns of the multiforms of these enzymes in cancer tissue from human liver, stomach, and lung were shown to differ from those of normal liver, stomach, and lung, respectively, by triethylaminoethyl cellulose column chromatography.

Alanine↗

Triglyceride metabolism in epididymal adipose tissue of obese animals.

Experiments were carried out to elucidate the mechanism of triglyceride accumulation in epidiymal adipose tissue of obese mice made by goldthioglucose injection. Specifically, fat mobilization and its deposition were investigated. In goldthioglucose-treated mice, the weight of the epididymal adipose tissue was 1,200 percent of that of control mice, while adrenaline-induced lipolysis and lipase activity of the tissue were 272 and 450 percent of control respectively. These results suggest that deposition of fat far exceeds fat mobilizing activity in the adipose tissue of the obese mice. It was found that triglyceride synthesis from glucose increased in the adipose tissue of these mice. Therefore, it is suggested that obesity in gold thioglucose-treated mice may not be due to decrease in fat mobilization but to increase in triglyceride synthesis from carbohydrate.

Acetates↗

Mechanism of actions of adrenaline and ACTH in fat mobilization.

Starvation did not cause increase of hormone-sensitive lipase in rat epididymal adipose tissue. Adrenaline did not activate lipase in the fat cells, although it accelerated the release of free fatty acids from the cells. The results suggest that the mechanism of the stimulation of lipolysis by adrenaline is different from that in the cyclic AMP theory. Adrenaline-sensitive fat globules were prepared by hypotonic treatment of fat cells. Lipolysis in the fat globules was stimulated by adrenaline. It was shown that adrenaline-induced lipolysis in the fat globules was not due to activation of lipase but to initiation of a reaction between lipase and triglyceride. It is well known that calcium ions are essential for ACTH-induced lipolysis and that the hormone stimulates calcium uptake into adipose tissue. It was demonstrated that calcium ions accelerated formation of a complex between fat and lipase. The mechanism of the actions of adrenaline and ACTH are discussed on the basis of these results.

Adipose Tissue↗