Studies of Incorporation of Radioactivity into Lipids by Human Blood: IV. Abnormal Incorporation of Acetate 1-C-14 into Fatty Acids by Whole Blood and Platelets from Insulin Independent Diabetics

Abstract

The incorporation of acetate 1-C-14 into fatty acids by whole blood and platelets from insulin independent diabetics has been determined. Whole blood from insulin independent diabetics incorporates significantly less C-14 into fatty acids than does whole blood from controls. As in previously reported studies done with blood cells from ketotic and nonketotic insulin dependent diabetics, a decreased percentage of fatty acid C-14 in palmitic acid (16:0) is found. This, however, exists as an isolated abnormality in whole bLiod from insulin independent diabetics. This abnormality may persist in some patients even when the fasting blood sugar is normal. The incorporation of acetate C-14 into fatty acids by platelets from insulin independent diabetics is quite similar to that of the control group. However, the pattern of incorporation of C-14 into fatty acids is abnormal. Percentage of C-14 in both myristic and palmitic acids is decreased, while percentage of C-14 in saturated and unsaturated fatty acids with retention time corresponding to 20:0 or greater is increased. These abnormalities bear no relationship to the fasting blood sugar at the time of study. These findings apparently mean that de novo synthesis of fatty acids is impaired in blood cells from both insulin dependent and insulin independent diabetics, while chain lengthening is relatively little affected.