Journal ArticleDOI
Vitamin A is stored as fatty acyl esters of retinol in the lacrimal gland.
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Data show that the lacrimal gland stores vitamin A as fatty acyl esters of retinol, which is similar to that of other tissues which require vitamin A.Abstract:
Many tissues which require vitamin A store the vitamin as long-chain fatty acyl esters of retinol. As part of a study designed to characterize vitamin A metabolism in the lacrimal gland, which transports retinol from blood to lacrimal gland fluid, extracts from lacrimal glands of rabbits and rats were analyzed by non-aqueous high performance liquid chromatography. Retinyl linoleate, retinyl palmitate, and retinyl stearate were identified in these extracts by their co-elution with standards, their retention time relative to retinyl palmitate, and their susceptibility to hydrolysis by saponification. Retinyl palmitate was present in rabbit lacrimal gland at 51.0 +/- 10.1 ng/g tissue. After treatment of vitamin A-deficient rabbits with orally administered [11,12-3H] retinyl acetate, the radiolabeled esters retinyl linoleate, palmitate, and stearate were extracted from the lacrimal glands. These data show that the lacrimal gland stores vitamin A as fatty acyl esters of retinol.read more
Citations
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Journal ArticleDOI
A Comparison of Vitamin A and Cyclosporine A 0.05% Eye Drops for Treatment of Dry Eye Syndrome
TL;DR: Both vitamin A eye drops and topical cyclosporine A 0.05% treatments led to significant improvement in blurred vision, tear film BUT, Schirmer I score results, and impression cytologic findings in patients with dry eye syndrome (P < .05).
Journal ArticleDOI
Chromatographic and electrophoretic analysis of biomedically important retinoids
TL;DR: HPLC with UV detection is still the method of choice for highly sensitive and selective retinoid determination, as well as for high sample throughput and robustness.
Journal ArticleDOI
Vitamin A Esterification in Human Epidermis: A Relation to Keratinocyte Differentiation
Hans Törmä,Anders Vahlquist +1 more
TL;DR: The in vivo esterification of vitamin A may be enhanced in terminally differentiating keratinocytes and also be of importance in relation to pathologic keratinocyte differentiation, according to a presumed pH gradient in upper epidermis.
Journal Article
The relationship between secretion of retinol and protein by the lacrimal gland.
TL;DR: Under all conditions of stimulation with pilocarpine and VIP that were studied, the retinol:protein ratio in lacrimal gland fluid of normal rabbits remained constant at 3.3 ngretinol/mg protein, which suggests that retinols is protein-bound in Lacrimal glands fluid.
Book ChapterDOI
Reversed-phase high-performance liquid chromatography of retinyl esters.
TL;DR: It has been found that mobile phases of acetonitrile with chlorinated hydrocarbons provide rapid and satisfactory separation of the most common retinyl esters in biological tissues, including the usually difficult-to-separate retinyl palmitate and retinyl oleate.
References
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Book ChapterDOI
Retinoids in Photosensitive Systems
TL;DR: The chapter describes the critical role of retinoid-binding proteins in the normal functioning of the vertebrate visual system and describes their occurrence as covalently linked prosthetic groups in the light-sensitive pigments.
Journal ArticleDOI
Retinol esterification by rat liver microsomes. Evidence for a fatty acyl coenzyme A: retinol acyltransferase.
TL;DR: Direct evidence for retinol esterification catalyzed by a microsomal acyl-CoA:retinol acyltransferase is provided and indirect evidence for a pool of fatty acyl -CoA in isolated liver microsomes that is available to react with [3H]ret inol to form esterified ret inol is indirect.
Journal ArticleDOI
The composition of liver vitamin a ester and the synthesis of vitamin a ester by liver microsomes.
Sidney Futterman,Andrews Js +1 more
TL;DR: The fatty acid composition of vitamin A ester isolated from the liver of the calf, sheep, rabbit, man, rat, frog, trout, and cat is described, and evidence is provided that the synthesis of vitamin C ester in the liver occurs in the microsomes.
Journal ArticleDOI
Metabolism of the retina. iv. the composition of vitamin a ester synthesized by the retina.
Journal Article
Retinol secretion by the lacrimal gland.
TL;DR: Dose-response studies show that intravenously administered pilocarpine and intra-arterial acetylcholine stimulate secretion of retinol by the lacrimal gland in a dose-response manner, and these observations are similar to the effects of cholinergic drugs and VIP on protein secretion by the Lacrimal glands.