Using the postimplantation rat conceptus model, we analyzed with gas-liquid chromatography, the
fatty acid composition in major
lipid groups (
phospholipids,
triglycerides,
nonesterified fatty acids, and
cholesterol esters) of yolk sacs and embryos cultured for 48 hours under control, hyperglycemic, and
arachidonic acid-supplemented hyperglycemic conditions. In all experimental conditions the yolk sacs had greater
fatty acid content than the embryos in all
lipid groups except in
nonesterified fatty acids. The
fatty acid level in embryonic
nonesterified fatty acids was significantly higher (p less than 0.05) in
hyperglycemia-exposed embryos than found with
arachidonic acid supplementation. Total yolk sac
triglycerides were greater with added
glucose (p less than 0.05) than with the addition of
arachidonic acid to the same medium.
Oleic acid, a
fatty acid associated with essential
fatty acid deficiency, was increased in the embryonic
phospholipids and
nonesterified fatty acids of conceptuses exposed to excess
glucose, as well as in the
culture media of this group, compared with the control or
arachidonic acid-supplemented, hyperglycemic group (p less than 0.05). The results of this study demonstrate that diabetes-related
embryopathy is associated with quantitative and qualitative abnormalities in major
lipid groups. Furthermore, the elevation in embryonic
oleic acid level suggests that the teratogenic mechanism could be related to a deficiency in
essential fatty acids. The pattern of essential
fatty acid deficiency and
embryopathy was preventable with
arachidonic acid supplementation in this experimental model.