Vitamin E distribution in ocular tissues following long-term dietary depletion and supplementation as determined by microdissection and gas chromatography-mass spectrometry.
Vitamin E is thought to be important for protection of polyunsaturated fatty acids (PUFA) from oxidative damage. A microbiochemical procedure using microdissection and gas chromatography-mass spectrometry was developed to determine vitamin E distribution in ocular tissues in a rodent model, with the eventual goal of using it in a study of phototoxic degeneration of the retina, where PUFA oxidation is potentially the causal mechanism. Sample preparation was achieved by freeze-drying the retina followed by micro-dissection to obtain the desired structures for analysis. A deuterated alpha-tocopherol internal standard is added to the tissue sample before extraction and derivatization which are achieved in a single step. The data presented show the vitamin-E content in various structures of the retina, particularly the outer segments and retinal pigment epithelium (RPE); however, the vitamin E content of other ocular tissues is also included. Data were obtained from albino and pigmented rats receiving vitamin E-depleted, supplemented, and regular chow diets, and from rabbits and cats receiving regular chow diets formulated for each species. Within all dietary groups the highest concentration of vitamin E was located in the RPE followed by the outer segments of the photoreceptor cells. Other ocular tissues consistently contained lower amounts of vitamin E. Different tissues were depleted of vitamin E at different rates and this points out the importance of determining vitamin E levels in tissues of interest in studies on the consequences of dietary depletion.
Stephens
R J
RJ
SRI International, Menlo Park, CA 94025.
Negi
D S
DS
Short
S M
SM
van Kuijk
F J
FJ
Dratz
E A
EA
Thomas
D W
DW
D000818:Animals; D002415:Cats; D002849:Chromatography, Gas; D013058:Mass Spectrometry; D010786:Photoreceptor Cells / Q000378:metabolism; D010857:Pigment Epithelium of Eye / Q000378:metabolism; D011817:Rabbits; D051381:Rats; D011919:Rats, Inbred Strains; D012160:Retina / Q000378:metabolism* / Q000648:ultrastructure; D012374:Rod Cell Outer Segment / Q000378:metabolism; D013997:Time Factors; D014810:Vitamin E / Q000008:administration & dosage / Q000378:metabolism*; D014811:Vitamin E Deficiency / Q000378:metabolism
D014810:Vitamin E