Ichiro Nakazawa

In vitro activity of the fatty acyl desaturases of human cancerous and noncancerous tissues.

The microsomal desaturase activity of human cancerous and noncancerous tissues was measured in vitro using 1-14C,-11,14-eicosadienoic and 1-14C-oleic acids as substrates. Tissues used were a case of ovarian cancer, a urinary bladder cancer, a rectal cancer, and a nonspecific colonic ulcer with appropriately normal tissues. When 11,14–20∶2 was used as substrate, radioactive tetraene and triene were produced. The tetraene was identified by radio gas chromatography as arachidonic acid (5,8,11,14–20∶4), and the triene had a retention time of 5,11,14–20∶3. Thus, the possibility arises that a Δ8 desaturase was involved. In the Δ6 desaturase, with the urinary bladder

Effect of transplanted human ovarian cancer tissue on liver lipid metabolism of nude mice

The changes in the lipids of liver tissues of nude mice with and without transplanted human cancerous tissues were studied to clarify the effect of transplanted human tumor tissues on host liver lipid metabolism. The total lipid was extracted and separated into phospholipid, triglyceride, and other fractions by thin layer chromatography. The amounts of methyl esters of fatty acids of each lipid fraction were measured by quantitative gas liquid chromatography after each lipid fraction had been subjected to methanolysis by 5% HCl-methanol. The phospholipid content of liver tissues of six tumor bearing nude mice was increased and the triglyceride content decreased in comparison with these fractions in three control nude mice. The ratio of the phospholipid fatty acid content to the triglyceride fatty acid content (phospholipid∶triglyceride [PL∶TG]) of six tumor bearing nude mice was distributed between 7.6 and 33.5, whereas PL∶TG ratios of three control nude mice were distributed between 1.7 and 3.8. This result was similar to that reported for human liver tissues of patients with malignant neoplastic disease, indicating that nude mice with transplanted human cancer may be useful for clarifying the mechanisms of the lipid-chemical changes of liver tissues of patients with malignancies.