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)

Carbamylation of lens proteins induced conformational changes and may play a role in the development of cataracts in uremic patients. Thus, the activities of the urea cycle enzymes: carbamyl phosphate synthetase I, ornithine transcarbamylase, argininosuccinate synthetase, argininosuccinase and arginase, were determined in lens, retina and ciliary body-iris of calf and rabbit. No ornithine transcarbamylase activity was found in ciliary body-iris, lens and retina of calf and rabbit whereas carbamyl phosphate synthetase I, argininosuccinate synthetase, argininosuccinase and arginase activities in calf lens were 5.02 +/- 0.21, 9.50 +/- 0.29, 9.17 +/- 0.16 and 6.32 +/- 0.19 [mumol (g protein)-1 hr-1], respectively. Except arginase, the activities of carbamyl phosphate synthetase I, argininosuccinate synthetase and argininosuccinase in lens were 30-50% of the values in retina or ciliary body-iris. The Km for each of the substrates was obtained for argininosuccinate synthetase, argininosuccinase and arginase of calf lens. Activities of carbamyl phosphate synthetase I, argininosuccinate synthetase, argininosuccinase and arginase in clear human lenses, aged 67-87 years, were 0.11 +/- 0.01, 0.67 +/- 0.01, 0.20 +/- 0.01 and 0.58 +/- 0.03 (mumol lens-1 hr-1), respectively. Two-fold increase in the activity of arginase was found in senile cataracts, but all other enzymes had 36-87% decreases in activities. It is likely that the rise in arginase activity in cataracts could facilitate polyamine synthesis through ornithine and ornithine decarboxylase and additional formation of cyanate, a carbamylating compound, both of which have been implicated in cataract formation. Further, decreased activities of argininosuccinate synthetase and argininosuccinase together with increased arginase activity could lead to the depletion of arginine in senile cataracts.
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PMID:Urea cycle enzymes in retina, ciliary body-iris, lens and senile cataracts. 649 61

Caffeic acid phenethyl ester (CAPE) was isolated from propolis (a product of honeybee hives) that has been used in folk medicine as a potent antiinflammatory agent. CAPE is cytotoxic to tumor and virally transformed but not to normal cells. Our main goal was to establish whether CAPE inhibits the tumor promoter (12-O-tetradecanoylphorbol-13-acetate)-induced processes associated with carcinogenesis. Topical treatment of SENCAR mice with very low doses (0.1-6.5 nmol/topical treatment) of CAPE strongly inhibits the following 12-O-tetradecanoylphorbol-13-acetate-mediated oxidative processes that are considered essential for tumor promotion: (a) polymorphonuclear leukocyte infiltration into mouse skin and ears, as quantified by myeloperoxidase activity; (b) hydrogen peroxide (H2O2) production; and (c) formation of oxidized bases in epidermal DNA, as measured by 5-hydroxymethyluracil and 8-hydroxylguanine. A 0.5-nmol dose of CAPE suppresses the oxidative burst of human polymorphonuclear leukocytes by 50%. At higher doses (1-10 mumol), CAPE inhibits edema and ornithine decarboxylase induction in CD-1 and SENCAR mice. Interestingly, we discovered that 12-O-tetradecanoylphorbol-13-acetate-induced H2O2 production in bovine lenses also is inhibited by CAPE. Cumulatively, these findings point to CAPE as being a potent chemopreventive agent, which may be useful in combating diseases with strong inflammatory and/or oxidative stress components, i.e., various types of cancer and possibly cataract development.
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PMID:Inhibition of tumor promoter-mediated processes in mouse skin and bovine lens by caffeic acid phenethyl ester. 768 Feb 81