Extracellular glucose dependence of rhodopsin regeneration in the excised mouse eye.
To study the process of rhodopsin regeneration a superfused excised whole eye preparation of the albino mouse was developed. With this preparation, complete regeneration could be observed after each of the first two illuminations (bleaching 15-20%), and incomplete regeneration after a third illumination. Regeneration was minimal at extracellular glucose concentrations of 0 or 1 mM with improved regenerations at higher concentrations. Maximum regenerations were observed at glucose concentrations of 4-10 mM. First-bleach regenerations were as follows: 0 mM glucose, 20%; 1 mM, 8%; 2 mM, 45%; 3 mM, 82%; 4 mM, 115%; 5.1 mM, 121%; 7 mM, 120%; and 10 mM, 126%. The effects of reduced glucose were reversible. After an initial bleach with 0 or 1 mM extracellular glucose that exhibited minimal regeneration, the re-addition of glucose (5.1 mM) restored the ability of the eye to regenerate rhodopsin following a second bleach, but only to the level prior to that bleach. Mitochondrial substrates fumarate (10 mM) or pyruvate (10 mM) partly substituted for glucose, exhibiting first-bleach regenerations of 56 and 85%, respectively.
Ostroy
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SE
Department of Biological Sciences, Purdue University, West Lafayette, IN 47907.
Friedmann
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AL
Gaitatzes
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CG
D000818:Animals; D004305:Dose-Response Relationship, Drug; D005123:Eye / Q000187:drug effects; D005260:Female; D005947:Glucose / Q000494:pharmacology*; D008027:Light; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D012243:Rhodopsin / Q000096:biosynthesis*; D013997:Time Factors
D012243:Rhodopsin; D005947:Glucose