V. the Role of Microsomes in Vitamin a Esterification in the Visual Cycle* J. Stevens Andrews and Sidney Futterman
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چکیده
In the course of light adaptation in the retina, the visual pigment, rhodopsin, which is located in the visual cell outer segment, releases vitamin A aldehyde (2, 3). The aldehyde is then enzymatically reduced to vitamin A (3) by reduced triphosphopyridine nucleotide (4) in the outer segment. The vitamin A is subsequently converted to vitamin A ester by the particulate matter of retinal tissue (5, 6). In view of these observations it has been generally assumed that the esterification of vitamin A also occurs in the outer se,ments of visual cells. In this report evidence is presented that this assumption is incorrect and that the esterification reaction occurs in retinal microsomes.
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