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)

A strain of rats with symptoms of inherited galactosemia (cataracts, hepatosplenomegaly, aminoaciduria etc) was produced by selection and inbreeding of Wistar rats highly susceptible to the galactosemic effect of galactose. The salient biochemical feature of these rats, like human galactosemics, is manifested as a decrease in the activity of galactose-I-phosphate uridyltransferase (Gal-I-PUT) in liver tissue and erythrocytes. However, the cross experiments have shown that the decrease in Gal-I-PUT activity was not required for expression of main galactosemia symptoms. Genetic analysis of cataract formation demonstrated that this trait was controlled by a single dominant gene. High transport rate of 14C-galactose into erythrocytes was a characteristic of galactosemic rats. Genetic analysis demonstrated that this trait was under the control of a single dominant gene, similar to the cataract formation. The intracellular accumulation of galactose ensured by its high transport, simultaneously with a decrease in Gal-I-PUT activity, were assumed to be the main reasons of galactosemic symptoms. The glucose transporter isolated from erythrocytes of the galactosemic rats, when integrated into the liposome membrane transferred more actively galactose into the liposomes than that of the control galactose resistant rats.
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PMID:[Elevated galactose transport into cells as the cause of development of hereditary galactosemia in rats]. 344 43

Hachimi-jio-gan (Rehmannia Eight Formula, pa-wei-ti-huang-wan or Bawei dihuang wan) is one of traditional Chinese medicines which has been used for treating various senile disease for a few hundred years. This drug was evaluated for its therapeutic efficacy to rat galactosemic cataract from the suppressive rate of variance of some biochemical parameters, whose variation with cataractogenesis or the advance of cataract have been reported already. The dose of 500mg of Hachimi-jio-gan/day/200g of rat body weight suppressed significantly the variations of hydration rate, Na/K ratios, and calcium ion level in the lens with the advance of galactosemic cataract, especially when the drug was administered by the pre- or concurrent-administration before or with 30% of galactose diet respectively. This drug also could delay the progressive rate of lens opacification. However, the drug had no effect to suppress the galactitol accumulation in the lens. From these results, we presume that a drug action of Hachimi-jio-gan may control the balance of sodium, potassium and calcium ions which are important in relation to the maintenance of lens transparency. Then, we realized, that this drug may have a prophylactic efficacy to diabetic cataract, though a more detail study should be needed to apply this drug to human cataract disease.
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PMID:The evaluation of therapeutic efficacy of hachimi-jio-gan (traditional Chinese medicine) to rat galactosemic cataract. 350 15

Lenses of rats maintained on a 50% galactose diet displayed the development of a progressive cataract which was cortical at 3-11 days, and progressively internalized (nuclear as well) and mature at 16-20 days of feeding. Lens fiber plasma membranes were isolated from female rats subjected to the galactose diet and from controls at 11, 19, and 31 days of feeding, and analyzed by SDS-PAGE. Examination of the fiber plasma membranes from whole lenses of galactose-fed rats demonstrated the limited proteolysis of MP26 into MP23-24, in both the cortical and mature stages of the resultant cataracts. The limited proteolysis of MP26 was first evident in the lens cortex at 11 days of galactose feeding, and was evident as well, and more severe in proportion, in the lens nucleus at 19 days of feeding. The greatest proportion in MP26 limited proteolysis was observed in whole lenses at 31 days of galactose feeding. The regional progression of MP26 limited proteolysis closely paralleled the morphological progression of the galactose-induced cataract in the rat. The proportion of lens MP26 which underwent limited proteolysis into MP23-24 increased the longer the animals were kept on the galactose diet.
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PMID:Limited proteolysis of MP26 in lens fiber plasma membranes of the galactose-induced cataract in the rat. 353 34

Galactosaemia has been suggested as a contributory factor in the pathogenesis of some presenile and senile cataracts. To assess whether galactosaemia plays any part in the development of atopic cataracts a galactose tolerance test was carried out in eight atopic dermatitis patients whose cataracts had appeared between the ages of 12 and 39 years. In seven patients a normal result was obtained and in one the result was just above normal. Impaired galactose tolerance appears to have no role in the pathogenesis of atopic cataract.
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PMID:Galactose tolerance in patients with atopic cataracts. 365 34

Secondary ion mass spectrometry (SIMS) is a surface analytical technique with high sensitivity for elemental detection and microlocalization capabilities within the micrometre range. Quantitative analysis of epoxy resins and gelatin have been reported (Burns-Bellhorn & File, 1979). We report here the first application of this technique to quantitative microlocalization in the context of a physiological problem--analyses of sodium, potassium and calcium in normal and galactose-induced cataract in rat lens. It is known that during the development of galactose-induced cataract the whole lens content of potassium is decreased, sodium is increased and, in late stages, calcium concentration increases. Whether these alterations in diffusible ions occur homogeneously or heterogeneously is not known. Standard curves were generated from epoxy resins containing known concentrations of sodium, potassium or calcium organometallic compounds using the Cameca IMS 300 Secondary Ion Mass Spectrometer. Normal and cataractous lenses were prepared by freezing in isopentane in a liquid nitrogen bath followed by freeze-drying at -30 degrees C. After dry embedding in epoxy resin, 10 microns thick sections of lens were pressure mounted on silicon wafers, overcoated with gold, and ion emission measured under the same instrumental conditions used to obtain the standard curves. Quantitative analysis of an area 27 microns in diameter, or a total analysed volume of 1.1 microns3, was performed by using a mechanical aperture in the ion optical system. Ion images provided qualitative microanalysis with a lateral resolution of 1 micron. Control rat lenses gave values for sodium and potassium content with a precision of +/- 17% or less. These values were compared to flame photometry and atomic absorption measurements of normal lenses and were accurate within 25%. Analysis of serum and blood also gave accurate and precise measurements of these elements. Normal rat lenses had a gradient of sodium, and, to a lesser degree, of potassium from the cortex to the nucleus. Development of galactose-induced cataract was heterogeneous by morphological criteria, beginning at the lens equator and spreading from the cortex into the nucleus. However, the loss of potassium and increase in sodium concentration occurred at early stages in both the cortex and nucleus cells, possibly because these cells are interconnected by gap junctions. There is a local alteration in elemental content prior to morphologically demonstrable cataract formation.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Quantitative microlocalization of diffusible ions in normal and galactose cataractous rat lens by secondary ion mass spectrometry. 382 Feb 81

Previous cytochemical and biochemical studies have shown an increase in the activity of acid phosphatase and arylsulfatase during the induction of galactose cataracts in rat lenses. It was postulated that these enzymes may be involved in lens fiber degradation observed during cataractogenesis, however, the role of these enzymes in the repair process was not ruled out. The present investigation has evaluated the level of acid phosphatase activity in lenses in which the induction of opacity is inhibited with the aldose reductase inhibitor sorbinil and during the recovery of galactose induced opacity. Sprague-Dawley rats received 50% galactose diet, or galactose diet with sorbinil, or laboratory chow diet. Following 20 days on this diet all rats received lab chow plus 50 mg kg-1 sorbinil (recovery diet). The lenses were removed at desired intervals following the initiation of the above three diets and following the transfer of animals to the recovery diet. Cytochemical localization and biochemical quantitation of acid phosphatase activity were performed with methods previously reported. Most of the enzyme activity was localized within the epithelial cells and superficial cortical fibers. In the epithelial cell layer, the enzyme activity was primarily localized in lysosomes and at extracellular sites near the epithelial cell membrane which abut each other and cortical fibers. In cortical fibers the enzyme activity was observed at various extracellular sites between the cell membranes of neighboring fibers. The effect of sorbinil, if any, and the possible role of acid hydrolases in the repair process during cataract reversal is discussed.
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PMID:Acid phosphatase II. Cytochemical localization in lenses of normal and galactose-fed rats. 392 63

We tried to counteract the appearance of galactosemic cataracts in weaned rats by high doses of vitamin E. Rats were fed a diet containing 33% galactose. Cataract development was monitored by biomicroscopy and by several biochemical parameters: K+/Na+ ratio, aldose reductase activity, level of protein and non-protein sulfhydryl (SH) groups. Vitamin E was given parenterally at a dose of 100 mg/kg/day. The K+/Na+ ratio drops after 15 days of galactosemia, while the level of the aldose reductase rises after only 5 days of treatment. The non-protein SH groups lens contents fall from the 5th day of treatment onwards, while protein SH groups are not affected. In short-term experiments vitamin E does not prevent biochemical changes caused by galactosemia. The oxidative insult does not seem to be primarily involved in galactose cataract.
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PMID:Changes of some biochemical parameters of the lens in galactose-treated weaned rats with and without vitamin E therapy. 392 May 97

Aldose reductase is implicated in the pathogenesis of sugar cataracts; therefore, inhibition of this enzyme subsequent to cataractogenesis may represent a therapeutic approach for the restoration of lens physiology despite the persistence of diabetes or galactosemia. In the present study, the effect of aldose reductase inhibition subsequent to stage-I cataract formation was investigated in the galactose-maintained rat. Our results indicated that despite continuation of galactose feeding the aldose reductase inhibitor, Sorbinil, a spirohydantoin, arrested further progression and promoted a reparative process. Quantitative analysis of scanning electron micrographs indicated that the afflicted lens regions were contained and their cellular components stabilized with regard to fiber hydration and interdigitation. The reparative process involved: decrease in lens dulcitol, gradual recovery of fiber thickness and partial restoration of lens myo-inositol content. At this stage of cataractogenesis, despite continuance of galactose feeding, the effects of Sorbinil treatment were comparable to the reparative process achieved by restoration of a normal diet.
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PMID:Reversal of stage-I sugar cataract by Sorbinil, an aldose reductase inhibitor. 392 28

NADPH and NADP+ levels were measured in rat lens from normal controls, from galactose-fed and diabetic rats during the first week of cataract formation. The level of NADPH in normal rat lens was determined to be 12.3 +/- 0.4 nmol/g wet weight, and that of NADP+ 4.6 +/- 0.2 nmol/g wet weight. In early cataract formation NADPH levels decreased rapidly during the first 2 days and then remained stable at 76% of control for galactose-fed and 84% for diabetic rats. NADP+ levels increased by 38% of control for galactose-fed and 54% for diabetic rats. Calculated NADPH/NADP+ ratios dropped from 3.36 +/- 0.21 to 1.86 +/- 0.16 in galactose fed rats, and from 2.81 +/- 0.15 to 1.61 +/- 0.16 in diabetic rats (P less than 0.001 for both experimental groups). These data are consistent with rapid NADPH oxidation during onset of lens cataracts. No significant changes in aldose reductase enzymatic activity levels were observed in either the galactosemic or the diabetic rats during the times measured.
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PMID:Aldose reductase, NADPH and NADP+ in normal, galactose-fed and diabetic rat lens. 392 85

Sorbinil, an aldose reductase inhibitor, in combination with diet normalization, arrested stage-II galactose cataract and restored lens transparency. During the reversal process, determination of lens dry weight, dulcitol and myo-inositol content as well as individual fiber cell ultrastructure offered a comprehensive index of lens integrity. In this study, young rats received a 50% galactose diet for 10 days to produce a stage-II sugar cataract. Then they were placed on one of the following diets: 50% galactose and Sorbinil (20 mg/kg); 50% galactose; normal diet, normal diet and Sorbinil (20 mg/kg). From each group, equal numbers were sacrificed at 5, 10 and 20 days. Although differences were obtained after 5 and 10 days, the 20-day reversal period provided the most significant findings. Only the combination of Sorbinil and normal diet restored lens transparency, normalized lens myo-inositol content and dry weight and partially restored fiber cell integrity as evidenced by diminished granulation and increased fiber synthesis. Neither Sorbinil treatment during galactose administration nor normal diet alone were sufficient to protect against further cataractogenesis, thus indicating a synergistic effect of Sorbinil in combination with normal diet.
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PMID:Synergism of sorbinil and normal diet on reversal of stage-II sugar cataract. 393 Nov 5


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