Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0086543 (cataract)
 29,165 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Glucocorticoid-induced cataract formation appears to proceed via oxidation or peroxidation steps possibly caused by multiple activities of glucocorticoid in the living system. Attempts were made to modify GC-induced metabolic changes and prevent cataract formation using intermediates of the citric acid cycle. The compounds were applied to the embryos at 3, 10 and 20 hr after the administration of hydrocortisone succinate sodium (HC:0.25 mumol/egg) to 15-day-old eggs. At 48 hr after HC treatment the lenses were classified and analyzed. Almost all lenses were classified as stage IV-V (greater than 94%). However, the application of sodium isocitrate (IC:15 mumol/egg) which was the most potent among several intermediates tested showed a significant preventive effect against cataract formation. The administration of IC prevented the decline of GSH, the elevations of LPO and reduced the marked elevation of glucose in the lens caused by HC. The IC treatment also diminished the elevation of LPO in blood and liver. The above effects by IC on HC-induced events may be due to the action of IC in preventing the early decline of hepatic GSH caused by HC. Possibly IC was utilized as an intermediate of the citric acid cycle and a substrate for isocitrate dehydrogenase in cytosol to modify GC-induced metabolic changes.
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PMID:Preventive effect of isocitrate on glucocorticoid-induced cataract formation of developing chick embryo. 191 99

In this paper various changes in glutathione level, which were influenced by balance of its synthesis, degradation, transport and utilization, were analysed in chick embryos administered with glucocorticoid (GC) or buthionine sulfoximine (BSO; an inhibitor of glutathione synthesis). When BSO (30 mumol egg-1) was administered twice to chick embryos on day 14 and 15, the GSH in both the lens and the liver decreased to 15-20% and 30-40% of the age-matched control level, respectively, between 24 and 48 hr after the second treatment, then began to recover. Although this decline in the GSH level in these tissues was greater and more prolonged in embryos treated with BSO than with GC, the former embryos maintained lens transparency even up to 144 hr by a visual examination. However, histological changes in the lens occurred after 96 hr and more significantly 144 hr after second administration of BSO. The changes mainly consisted of pale epithelial cells on the anterior peripheral surface of the lens, irregular height of the epithelial cells at the equator, clefts between the epithelium and the cortex and swelling of almost all the cortical fibers. These observations may suggest that BSO treatment could produce the beginning of a cataract. Embryos with GC-cataract revealed the following changes at 48 hr: loss of transparency, elevation of LPO (TBA-reacting substance) in the lens, the blood and the liver. These were not observed in BSO-treated embryos during the experimental period. The GC-cataract may well depend on the generation of LPO. BSO cataract, having a distinct mechanism compared to that caused by GC, develops more slowly in GSH-depleted lenses. The BSO-treated chick embryos will be a useful model to screen the risk factors which accelerate cataract formation.
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PMID:Comparison of lens biochemistry and structure between BSO-treated and glucocorticoid-treated developing chick embryos. 906 74

A dependency was found between total protein content and cataract maturity (P=-0.91, p<0.01). LPO intensity sharply increased and remained stably high after appearance of lens opacity. A strict negative correlation was found between the content of polyunsaturated fatty acids in earwax and lens nucleus (P=-0.7, p<0.01). The content of conjugated dienes, crotonic aldehyde, and Schiff bases decreased during cataract development. The content of vitamins B(2), A, and E decreased with increasing brown coloration of lens nucleus. Studying the parameters of lipid metabolism in wax-producing glands of the external ear canal we can evaluate the disturbances in lipid metabolism in the lens, which was confirmed by the correlation between fatty acid composition of the earwax and lens nucleus. These data do not demonstrate the dependence of the lens state on earwax, but suggest general features of the process in organs and tissues during aging. Some markers in the blood of patients with cataract change during progress of lens opacity and intensification of brown coloration of lens nucleus, but these changes are inspecific and reflect general activation of peroxidation processes and antioxidant system.
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PMID:Systemic markers of age-related changes in the lens. 2286 16