Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011849 (diabetes)
 277,896 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the lens, disorders of the metabolism occur, and, with them, active permeability (the cation pump with uptake of K and release of Na) changes to passive permeability and consequently Na ions enter with water. As a result, the lens increases in weight and a subcapsular (permeability) cataract develops. It is shown that the cattle lens in vitro increases in weight the lower the pH (6.5 greater than 7.5 greater than 8.5) of the surrounding fluid becomes. In a further experiment, 1 ml of buffered liquids with different pH were injected into the anterior chamber of the eyes of freshly slaughtered cattle. Here, too, the mechanically undamaged, untouched lens increased in weight more greatly as the pH (5.5 greater than 6.5 greater than 7.5 greater than 8.5) of the injected fluid was lowered. The significance of the lowering of the pH, e.g., in local inflammation (iritis, cyclitis, retinitis, etc.) or general acidoses (diabetes mellitus, galactosemia, hunger, extracorporeal circulation for atrophic kidney. Albright-, Love-, Fanconi-syndrome) for the appearance of incipient subcapsular clouding of the lens is pointed out.
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PMID:[Lens changes occuring as a result of lowered pH (acidosis) (author's transl)]. 1 65

Cataracts removed intracapsularly by cryoprobe technique from human diabetics were analyzed for sugars and polyols by gas liquid chromatography. The contents of sorbitol and fructose of lenses followed blood glucose levels at least up to 250 mg/dl. Studies indicate that human lens is capable of synthesizing substantial amounts of polyol pathway metabolites given exposure to high glucose levels such as are prevalent in diabetes. The synthesis of sorbitol was found to be susceptible to quercitrin, an inhibitor of aldose reductase. The implications of these findings in the formation of cataracts in diabetic individuals have been discussed.
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PMID:Implications of aldose reductase in cataracts in human diabetes. 10 20

Immediately after cataract extraction, lenses from diabetic and nondiabetic patients were collected, classified, and assayed or incubated in high-glucose medium. The distribution of cataract types within the diabetic and nondiabetic groups was almost identical. The aldose reductase (AR) inhibitor AY22,284 (Alrestatin) was as effective in blocking sorbitol formation in diabetic as in nondiabetic lenses. While there was no difference in the level of intralenticular glucose, the diabetic lens produced significantly more sorbitol than did the nondiabetic lens. Also, the activity of polyol dehydrogenase (PD) was much lower in the diabetic population. The diabetic lenses swelled slightly more (P <.2) than nondiabetic lenses in high glucose media, and AY22,284 was effective in reducing the swelling of diabetic lenses in 35.5 mM glucose medium. While these results are preliminary, they suggest that diabetes, in some way, may confer on the human lens an increased susceptibility to osmotic stress via the sorbitol pathway. It is also reassuring to note that an AR inhibitor is no less effective in blocking the more active AR in the diabetic than in the nondiabetic lens. The therapeutic implications of this are discussed.
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PMID:Efficacy of Alrestatin, an aldose reductase inhibitor, in human diabetic and nondiabetic lenses. 12 68

In some tissues containing aldose reductase, increased flux through the polyol pathway has been implicated as being causative in diabetic complications (e.g., cataracts, peripheral neuropathy). We have found CP-45,634 (d-6-fluoro-spiro[chroman-4,4'-imidazolidine]-2',5'-dione) to be a highly potent, structurally novel, uncompetitive inhibitor of calf lens aldose reductase (IC50 approximately 5 X 10(-7)M). In a system in which sorbitol accumulation in isolated rat sciatic nerves was monitored in the presence of high (50 mM) glucose concentrations, CP-45,634 produced inhibition of polyol accumulation at levels as low as 1 X 10(-6)M. To determine if in vitro activity would translate to in vivo models, sorbitol accumulation in rat sciatic nerves was measured 27 hr after induction of diabetes with streptozotocin. Orally administered CP-45,634 was effective at dose levels as low as 0.25 mg/kg, t.i.d., and at 0.75 mg/kg produced an 85% inhibition of sorbitol accumulation. Two weeks after induction of diabetes by streptozotocin, sorbitol levels in rat lens and the sciatic nerve rose to 21,203 nmole/gm and 1,161 nmole/gm, respectively. Subsequent oral administration of CP-45,634 (2.5 mg/kg, b.i.d.) for 1 wk reduced these levels by 92% in nerves and 90% in lenses. In galactosemic rats, CP-45,634 inhibited the rise in lens galactitol and effectively delayed cataract formation at oral doses as low as 5 mg/kg/day. These high levels of in vivo activity suggest that CP-45,634 has potential for assessing the role of the polyol pathway in diabetic complications.
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PMID:CP-45,634: a novel aldose reductase inhibitor that inhibits polyol pathway activity in diabetic and galactosemic rats. 12 97

1. Cataract formation in streptozotocin-induced diabetes in rats was reduced by approximately 85% when a diet rich in maize oil (300 g/kg diet) (fat diet) was given, thus confirming results of earlier studies. However, the concentration of sorbitol in the lens of diabetic animals remained high, the values for diabetic rats given the standard diet and the fat died being 65 and 40 mumol/g protein respectively. 2. With the standard diet, the fatty acid profile of the triglycerides of the epididymal fat pads was characterized by a greater relative proportion of saturated fatty acids for the diabetic animals compared to that for the normal animals. The fat diet moderated the tendency towards saturation in the diabetic animals. 3. The fat diet had other effects on the diabetic animals; these included a reduced mortality rate, increased body-weight, a decrease in the daily water intake, and in the daily urinary excretion of glucose and urea. 4. In the diabetic animals the fat diet had no effect on the specific activities in the liver of hexokinase (EC 2.7.1.1), glucokinase (EC 2.7.1.2), phosphofructokinase (EC 2.7.1.11) and pyruvate kinase (EC 2.7.1.40). However, the specific activity of glucose-6-phosphatase (EC 3.1.3.9) was reduced, while that of malate dehydrogenase (decarboxylating) (NADP) (EC 1.1.1.40) was increased. The NAD+:NADH ratio, as calculated from liver pyruvate and lactate concentrations, tended to increase. 5. The results suggested that the fat diet moderated the long-term metabolic effects of diabetes.
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PMID:The effect of an unsaturated-fat diet on cataract formation in streptozotocin-induced diabetic rats. 13 11

The influence of daily subcutaneous cortisol injections (10 mg/kg) on the development of cataracts in streptozotocine (STR) diabetes was studied in 6 groups of Wistar rats (n = 10). Cataracts occurred only in the two groups subjected to high STR doses (60 mg/kg). We were astonished to find that in cortisol-treated diabetic animals there were lower blood glucose levels, fewer cases of glucosuria, and less pronounced cataracts than in rats treated with STR only. As STR had been administered after the start of cortisol therapy, it is assumed that the steroid had caused a protection of pancreatic B cells against STR and the onset of a less severe diabetes.
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PMID:[The influence of cortisol treatment on the development of diabetic cataracts in rats (author's transl)]. 13 12

Using the age-sex-specific data collected in the Framingham Heart Study 1948--1964 together with ophthalmic diagnoses made in the Framingham Eye Study in 1973--1975, the following variables were found to be associated with senile cataract: education, casual blood sugar, systemic blood pressure, height, vital capacity, serum phospholipid and hand strength; with senile macular degeneration: systemic blood pressure, height, vital capacity, left ventricular hypertrophy, hand strength and history of lung infection; with diabetic retinopathy: casual blood sugar, urine sugar and other specific elements of diabetes; with ocular hypertension: systemic blood pressure, height, casual blood sugar and pulse rate. No variables were identified as associated with open-angle glaucoma. The paper stresses the need for corroboration of these findings, which may be a mix of real and chance associations, and the need for additional analyses before any of these associations are considered evidence of factors related to risk of ophthalmic disease.
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PMID:The Framingham Eye Study. II. Association of ophthalmic pathology with single variables previously measured in the Framingham Heart Study. 14 82

The authors report a case of Steinert's disease in a woman and discuss the endocrine profile of this disease after giving an account of the criteria of diagnosis. Disorders of gonad function are mild in women, primary testicular atrophy is very frequent in man with reduction in 17-ketosteroids and testosterone. Thyroid function was normal but, in a few cases, a low fixation curve was found (our case) corrected by TSH stimulation. The frequency of cataract emphasizes the interest of this sign for detection. Diabetes, associated with hyperinsulinism, seemed more frequent than in a population without Steinert's disease. The pathogenesis of these endocrine disorders appears secondary and is ill explained if one considers it as a single disease. Better knowledge, no doubt linked to progress in biochemistry of normal and myopathic muscle, will help to explain the pathogenesis.
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PMID:[Endocrine aspects of Steinert's disease]. 18 36

The analysis of IgE in aqueous humor yielded an average concentration of 3.4 +/- 0.97 U/ml for 22 cataract patients and 5.5 +/- 3.42 U/ml for five uveitis patients. The IgE level in aqueous humor (IgEa.h.) of the cases examined is most probably, beside hematoocular diffusion of serum IgEs, the result of intra-ocular IgE production. In comparison with (mostly normal) IgEs levels, the IgEa.h. concentration appears relatively elevated, not only with uveitis patients, but also with cataract patients, above all when lenticular opacity is accompanied by other ophthalmic diseases (glaucoma, high myopia, diabetes). This "increase" of IgEa.h. concentration in very probably due to the radioimmunosorbent (RIST) technique employed, the most sensitive method available at the time of the present study. Thus, the calculated IgEa.h. value in the cataractous eyes should be regarded simply as approximate to the normal IgEa.h. concentration. These values are of clinical significance however, since a reference IgEa.h. mean-value is indispensable to the interpretation of pathologically high IgEa.h. levels and ethics do not permit of IgEa.h. determination in healthy eyes. The mean IgEa.h. levels of the delayed-type uveitis and cataract patients examined reveal no significant differences. IgEa.h. determination could make a contribution to the etiological clarification of, for example, immediate-type uveitis cases and intra-ocular parasitosis and serve as an appropriate model to study intra-ocular immunomechanisms.
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PMID:Immunoglobulin E in human aqueous humor and corresponding serum. A physiopathological and clinical study. 31 97

Oral administration of quercitrin, an inhibitor of aldose reductase, leads to a significant decrease in the accumulation of sorbitol in the lens of diabetic Octodon degus. The onset of cataract is effectively delayed when quercitrin is continuously administered. Thus in these diabetic animals, as in galactosemic rats, the use of an effective aldose reductase inhibitor impedes the course of cataract development. These observations support the hypothesis that in diabetes, as in galactosemia, aldose reductase plays a key role in initiating the formation of lens opacity.
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PMID:Diabetic cataracts and flavonoids. 40 44


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