抄録
The authors studied the in-vitro incorporation of 1-C-14-acetate into major fatty acids by diabetic whole blood and platelets suspended in own plasma. Although the C-14 incorpo-ration into fatty acids is generally suppressed in diabetes, relatively great suppression of C-14 incorporation is observed at palmitate and myristate made via malonyl Co-A pathway and relatively less suppression is seen at stearate and 20-carbon fatty acids made via chain-lengthening pathway. The grade of abnormalities of the C-14 incorporation seems to be closely related to the severity of diabetes.
With 1.47 ×10-2 Mol/l alloxan, the typical diabetic pattern of C-14 incorporation is repro-duced both in whole blood and platelet suspension derived from healthy subjects. At a given concentration of alloxan, the diabetic pattern appears more strongly in platelet suspension than in whole blood. In platelet suspension, alloxan can definitely reproduce the diabetic pattern even at the concentraton of 0.2 ×10-2 Mol/l (28.5mg%).
Both dehydroascorbic and ascorbic acids also reproduce the typical diabetic pattern of C-14 incorporation in healthy whole blood and in platelet suspension. Between these two compounds dehydroascorbic acid exhibits stronger effect in either whole blood or in platelet suspension. And between the two incubation media, platelet suspension show more extensive pattern of diabetic C-14 incorporation at a given concentration of either one of dehydroascorbic and ascorbic acids. In platelet suspension of healthy subjects the diabetic pattern is clearly reproduced with ascorbic acid at the concentration of 5.68 ×10-6 Mol/l (Img%).
As C14O2 production from the incubated whole blood with one of alloxan, dehydroascorbic and ascorbic acids is definitely increased as compared with that from control samples, the above three compounds seem to accelerate the function of citric acid cycle.
Some uncouplers of oxidative phosphorylation such as barbital, progesterone, cortisone, 1, 2-naphthoquinone and vitamin K3 also reproduce the typical diabetic pattern of C-14 incor-poration.
From the results described above it could be suggested that alloxan, dehydroascorbic and ascorbic acids act as uncouplers of oxidative phosphorylation and bring about suppressed production of ATP which in turn reproduce the diabetic pattern of C-14 incorporation, and that the “-CO”radical of the above three compounds functions as an important key factor for the appearance of the diabetic pattern of C-14 incorporation in both healthy whole blood and platelet suspension.
