Decreased docosahexaenoic acid levels in retina and pigment epithelium of frogs fed crickets.
Whole retina, rod outer segments, and retinal pigment epithelium of frogs (Rana pipiens) fed crickets for more than 1 year had significantly lower levels of docosahexaenoic acid (22: 6n-3) than the same tissues of frogs fed crickets for less than 1 month. Decreases in 22:6n-3 levels in these tissues were compensated for by increases in the n-6 polyunsaturated fatty acids (PUFAs), primarily 22:5n-6. There were no changes in the levels of saturated, monoenoic, or dienoic acids. Analysis of diacyl phospholipid molecular species (PLMS) revealed decreases in both the 22:6(n-3)-containing dipolyenoic molecular species in phosphatidylethanolamine and phosphatidylserine, and the monopolyenoic molecular species in phosphatidylcholine. These PLMS were replaced by species containing 22:5n-6 or other n-6 PUFAs. Examination of fatty acid methyl esters of total lipids extracted from crickets revealed that less than 1 mol% fatty acids were of the n-3 family, while more than 30 mol% were of the n-6 family. Thus, frogs raised on an n-3-deficient diet have reduced levels of n-3 PUFA in their retinas, rod outer segments, and retinal pigment epithelium. Although such changes have been reported for mammals, this is the first report of the effects of n-3 deficiency on the lipids of amphibians.
Chen
H
H
Cullen Eye Institute, Baylor College of Medicine, Houston, TX 77030.
Wiegand
R D
RD
Anderson
R E
RE
D000818:Animals; D002855:Chromatography, Thin Layer; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage*; D004281:Docosahexaenoic Acids / Q000378:metabolism*; D015525:Fatty Acids, Omega-3 / Q000378:metabolism; D006135:Gryllidae; D010743:Phospholipids / Q000378:metabolism*; D010857:Pigment Epithelium of Eye / Q000378:metabolism*; D011894:Rana pipiens; D012160:Retina / Q000378:metabolism*; D012374:Rod Cell Outer Segment / Q000378:metabolism
D004042:Dietary Fats, Unsaturated; D015525:Fatty Acids, Omega-3; D010743:Phospholipids; D004281:Docosahexaenoic Acids