ラット脂肪組織の脂質合成におよぼす正常人血清および血清中添加インスリンの影響

Rat epididymal adipose tissue was incubated in the normal human serum in the presence and absence of insulin, and the incorporation of labeled glucose and acetate into major lipid fractions and individual fatty acids was compared as these in Kreb's bicarbonate buffer. The results were as follows: 1) The incorporation of (14)C from 1-(14)C glucose or 1-(14)C acetate into fatty acids of adipose tissue was increased by the serum containirlg 50μU/ml of added insulin, but the incorporation was inhibited about 20% by serum with 800μU/ml of added insulin. 2) The percentage of recovered cpm incorporated into various fatty acids showed some difference in the serum as compared to the values in buffer. Although the percentage of 14:0 and 16:1 was decreased and 16:0 and 18:0 was increased by the serum, the changes found in these fatty acids were less sensitive to the effect of added insulin. The formation of 18:1 was most sensitive to added insulin in serum and the change of synthesis of this fatty acid reflects most specifically the stimulatory or inhibitory effect of insulin on the formation of total fatty acids in serum. 3) The effect of insulin as was found in fatty acid formation in serum was also appeared in the formation of non-saponifiable fraction in serum, but the glycerol formation was almost independent on insulin effect. 4) Dialyzed sernm with 200μU/ml of added insulin stimulated the fomation of total fatty acids remarkably, but the formation of 18:1 was also depressed in this condition, then, it is conceivable that the formation of 18:1 has some difference in nature as compared to others.