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)

Cholesterol synthesis rate, as determined by 3-hydroxy-3-methylglutaryl coenzyme A reductase activity, is characterized in the major organs of genetically diabetic mice. Both C57BL/Ks db+/db+ and C57BL/6 ob+/ob+ mice are hyperinsulinemic and insulin-resistant. These animals demonstrate loss of the circadian rhythm of hepatic reductase activity and a tendency for increased intestinal activity. As a result, proportionally more endogenous cholesterol synthesis occurs in intestinal mucosa than liver in genetically diabetic animals. Thus, the alterations in activity of 3-hydroxy-3-methylglutaryl coenzyme A reductase which are observed in animal models of diabetes are the result of diminished insulin effect rather than insulin level.
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PMID:Hepatic and intestinal 3-hydroxy-3-methylglutaryl coenzyme A reductase activity in genetically diabetic mice. 687 Aug 77

Rats with streptozotocin-induced diabetes stop growing, develop high cholesterol and triacylglycerol levels in plasma, and have decreased activity of the rate-limiting enzyme in cholesterol synthesis, 3-hydroxy-3-methylglutaryl CoA reductase (EC 1.1.1.34), in liver and increased activity in small intestine. They also eat more than normal. To determine the contribution of hyperphagia to these changes in lipid metabolism, we restricted intake of chow to the amount eaten ad lib by normal rats. Rats were meal-fed for 8 or 22 days from the time diabetes was induced. This regimen normalized reductase activity in both liver and intestine at mid-dark and mid-light, and all but eliminated high plasma cholesterol and triacylglycerol levels, although plasma insulin remained low and glucose remained high. Activation of hepatic reductase by endogenous phosphatase in vitro was reduced in hyperphagic diabetic rats but was normal in diabetic rats eating a normal amount of food. We conclude that hyperphagia, rather than direct effects of insulin deficiency as is usually assumed, is responsible for perturbations of lipid metabolism in chronically diabetic rats. These results support the proposal that hyperphagia increases the input of dietary and newly synthesized cholesterol from the small intestine, and that this increased input raises plasma cholesterol level and inhibits reductase activity in liver.
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PMID:Preventing hyperphagia normalizes 3-hydroxy-3-methylglutaryl-CoA reductase activity in small intestine and liver of diabetic rats. 695 13

Several vitamins have been demonstrated to interfere with the pathogenesis of some metabolic diseases, mainly by three different mechanisms: 1) vitamin malabsorption, 2) errors in vitamin metabolism, 3) vitamin dependent syndromes. The latter is due to a deficiency of the apoenzyme whose coenzyme is the vitamin itself. In this case pharmacological, instead of nutritional doses of the vitamin may be needed. The vitamins which interfere with inborn metabolic errors are reviewed; for each vitamin the corresponding diseases which may be treated are indicated. The vitamins are: 1) thiamine (leucinosis); b) nicotinic acid (hyperlipoproteinemia); c) biotin (beta-methyl-crotonyl-glycinuria, propionic aciduria); d) pyridoxine (infantile convulsions, familial pyridoxine responsive anemia, homocystinuria, cystathioninuria, xanthurenicaciduria); e) cobalamins (congenital intrinsic factor deficiency, cobalamin malabsorption, transcobalamin deficiency, methylmalonic aciduria) f) folic acid (congenital folic acid malabsorption, formimino-transferase deficiency, methylenetetrahydrofolic reductase deficiency, Lesch-Nyhan syndrome); g) vitamin D (phosphatic diabetes, Prader's type rickets, Albright's syndrome; essential hereditary hypophosphatemia, etc). It is noteworthy that the vitamin therapy of these diseases, not only corrects the metabolic errors, but can also promote the healing or the amelioration of the psycho-physical growth, of central nervous system alterations and of other lesions.
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PMID:[Vitamins in metabolic diseases]. 702 68

We examined the effect of streptozotocin-induced diabetes on the rate-limiting enzyme in cholesterol synthesis, 3-hydroxy-3-methylglutaryl CoA reductase (EC 1.1.1.34), in liver and small intestine of rats. During the acute phase of insulin deficiency (first day), food intake, plasma cholesterol, and reductase specific activity in liver all decreased. By 3 days, food intake, plasma cholesterol, and reductase activity in small intestine were all increasing. After 1 week, total reductase activity in small intestine was 2.5 times normal, whereas activity in liver remained low. Thus diabetes shifted the major site of cholesterol synthesis from the liver to the small intestine. These data support the proposal that hyperphagia by diabetic rats leads to increased input of both dietary and newly synthesized cholesterol by the small intestine into thoracic lymph and thereby contributes significantly to their hypercholesterolemia. The possibility that diabetes affected the F--inhibitable activation of reductase in vitro was also tested. There was no evidence of an effect in small intestine, but activation of reductase in vitro was decreased by 1/3 in liver. These data suggest that, in liver, either the activity of the activator was decreased or the fraction of reductase in the active state was increased after more than 12 hr of insulin deficiency.
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PMID:Total hydroxymethylglutaryl CoA reductase activity in the small intestine and liver of insulin-deficient rats. 704 79

Arylsulfonylamino acids, displaying a wide range of inhibitory activities versus rat lens aldose reductase (RLAR), were analyzed for enzyme selectivity in several test systems. These RLAR inhibitors were found not to produce significant inhibition of genetically-linked reductases (aldehyde reductase, ALR), catalytically similar reductases (Pachysolen tannophilus xylose reductase, PTXR), functionally distinct oxidoreductases (glutathione reductase, GR, lactate dehydrogenase, LDH, and gamma-transaminase, GABA-T), and thymidylate synthase (TS). These data suggest that aldose reductase differs significantly from other oxidoreductases in its inhibitor binding domain(s). Furthermore, the aldose reductase selectivity demonstrated by the arylsulfonylamino acids suggests that these compounds may not inhibit other key metabolic transformations in various cell types and that they may function as selective probes for studies of the relationship between aldose reductase mediated biochemical changes and the pathologies of chronic diabetes.
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PMID:Enzyme selectivity analyses of arylsulfonylamino acid aldose reductase inhibitors. 750 72

Peptide fragments of rat liver 5 alpha-reductase were synthesized according to the published primary sequence data. The peptide were used (i) in free form and (ii) linked to keyhole limpet hemocyanin (KLH), respectively, for immunization of rabbits. Resulting antisera showed positive reaction with the respective peptide-antigen in an ELISA. In Western blot experiments the antisera specifically recognized a 26,000 mol wt protein in extracts from female and male rat liver. All antisera, as well as isolated immunoglobulins, showed inhibition of 5 alpha-reductase activity in microsomes prepared from rat liver. Positive immunohistochemical reactions were observed in the perinuclear cytoplasm of hepatocytes. No reaction was seen in Kupffer- and connective tissue cells. Acinar heterogeneity of the immunoreaction was seen in the male rat liver with a gradient from the portal canal to the central vein. After androgen-deprivation a considerable increase in immunoreactivity was seen in male rat liver cells, indicating androgen-dependent suppression of the enzyme in male liver.
Exp Clin Endocrinol Diabetes 1995
PMID:Distribution of rat hepatic steroid 5 alpha-reductase 1 as shown by immunohistochemistry. 755 73

Diabetic neuropathy (DN) is chronic complication which occurs in 50% of long standing diabetes mellitus. DN is a consequence of hyperglycemia probably through the following mechanisms: a) activation of aldose-reductase, intracellular sorbitol accumulation and myoinositol depletion, reduced activity of Na+/K+ATPase, loss of Na+ channels and demyelination; b) proteins glycation; c) microangiopathy; the first mechanism being the best known and the most reliable. DN may be subclinical or clinical. The main clinical picture is a peripheral, bilateral, symmetric polyneuropathy with a "socks and gloves" sensory impairment, muscular weakness, hyporeflexia, plantar ulcers and arthropathy. Less frequent syndromes are proximal motor neuropathy and mononeuropathy of cranial nerves or thoraco-abdominal roots. Diagnosis is based on clinical data, and may be sustained on impaired nerve conduction velocity, abnormal evoked somatosensory potentials, or sural nerve biopsy. These methods are highly sensitive but unspecific. Etiopathogenic treatment is based on glycemic control and aldose reductase inhibitors. Improvement in clinical, electrophysiologic and histopathologic data have been obtained with the latter. Symptomatic treatment includes carbamazepin, phenytoin, tricyclic antidepressives and a phenotiazin. Mononeuropathies tend to complete recovery in less than 6 months. Polyneuropathy is thought to be irreversible and progressive; however, with excellent glycemic control or with aldose reductase inhibitors nerve damage may be stabilized or even reversed.
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PMID:[Diabetic neuropathy. Current concepts on etiopathogenesis, diagnosis, and treatment]. 755 46

Apolipoprotein (a)-Lp(a)-is reported to be an independent risk factor for coronary artery disease and for hemodialysis (HD) access occlusion. Homology with plasminogen may predispose to thrombosis. High concentrations usually have been reported in patients on HD and on continuous ambulatory peritoneal dialysis (CAPD), but near-normal values in many kidney transplants (TP). We used Pharmacia immunoradiometric assay in 52 patients on HD, 58 on CAPD, 94 after TP, and 56 controls. The Lp(a) mean levels for CAPD, HD, TP, and control groups were 738, 647, 348, and 368 U/l and the medians were 542, 537, 96 and 143 U/l, respectively. The means and medians for CAPD and HD were significantly greater than those for TP and controls (p < 0.003 for means and < 0.005 for medians). We found no significant difference between: (1) Lp(a) means or medians comparing HD and CAPD or TP and controls; (2) Lp(a) means for the 33 patients with insulin-dependent diabetes mellitus and the 171 without; (3) number of occlusions of HD fistulae or grafts in patients with high Lp(a) values and without; (4) mean Lp(a) for CAPD patients on gemfibrozil and also for TP patients on 3-hydroxy-methylglutaryl coenzyme 1 reductase inhibitors, or diet alone, before and after treatment, and (5) mean Lp(a) values for HD and CAPD patients with and without myocardial infarction. Lp(a) did not correlate significantly with fractional shortening or left ventricular end systolic or diastolic diameter by echocardiogram or with ejection fraction. For TP patients, Lp(a) and serum creatinine correlated (p = 0.004), and mean Lp(a) for 71 TP on ciclosporin A exceeded that for the other 23 patients (p < 0.03). Lp(a) fell in 13 of 14 patients after TP (mean fall 77%). The dominant Apo(a) isoform in 10 of 13 patients on CAPD or HD with high Lp(a) values was the equivalent of S2 (Utermann). Lp(a) in HD or CAPD is often elevated and regulated by both genetic and renal failure factors, but falls after TP with return of renal function and mainly genetic regulation. Lp(a) was not a risk factor for coronary artery disease in HD or CAPD patients and did not fall significantly with two drugs or diet.
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PMID:Comparison of Lp(a) concentrations and some potential effects in hemodialysis, CAPD, transplantation, and control groups, and review of the literature. 756 98

A case of acute inflammatory myopathy associated with the use of pravastatin, a new hydrophilic 3-hydroxy-3 methylglutaril coenzyme A reductase inhibitor, is reported. The patient, a 69-year-old man was affected by non-insulin-dependent diabetes mellitus and hypertension. He assumed pravastatin (20 mg/day) because of hypercholesterolemia. He was admitted with acute myopathy of the lower limbs which resolved in a few days after pravastatin discontinuation. A previously unknown hypothyroidism, probably due to chronic autoimmune thyroiditis, was evidenced. Muscle biopsy (left gastrocnemius) revealed a perimysial and endomysial inflammatory infiltrate with a prevalence of CD4+ lymphocytes. While lovastatin and simvastatin have been associated with toxic myopathy, pravastatin-associated myopathy could represent a distinct, inflammatory entity.
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PMID:Pravastatin-associated myopathy. Report of a case. 760 76

This study estimated the cost-effectiveness of the 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors available in Canada for the primary prevention of coronary heart disease (CHD). A model of the cost-effectiveness of therapy used to modify low-density lipoprotein (LDL) cholesterol and high-density lipoprotein cholesterol levels was developed in the primary prevention of CHD based on risk functions from the Framingham Heart Study and Canadian data on coronary risk factors and the cost of treating the leading manifestations of CHD. Relative to no treatment, discounted gains in life expectancy range from 0.174 year for fluvastatin 40 mg to 0.215 year for simvastatin 10 mg. Costs per year-of-life-saved range from $38,800 for fluvastatin 40 mg to $56,200 for pravastatin 20 mg. In the incremental analysis relative to fluvastatin 40 mg, additional gains in life expectancy range from 0.011 year for pravastatin 20 mg to 0.041 year for simvastatin 10 mg, and incremental cost-effectiveness ratios range from $88,200 for simvastatin, 10 mg to $330,300 for pravastatin 20 mg. Our analysis showed that the cost-effectiveness of cholesterol-lowering therapy is sensitive to pretreatment risk of CHD, as expressed by pretreatment cholesterol levels and the presence of additional risk factors such as hypertension, diabetes, and smoking. The results of the analysis suggest that it is more cost-effective to initiate treatment with fluvastatin than with pravastatin, simvastatin, or lovastatin. Sensitivity analysis showed the results to be stable even if the lipid-lowering effect of fluvastatin is varied by 23% from the original assumption of 25% LDL reduction (ie, from 19.3% to 30.8%). Limitations of the study are recognized and discussed. A head-to-head comparison of these HMG-CoA reductase inhibitors could provide further evidence that therapy initiated with fluvastatin may be the most cost-effective way to treat patients with hypercholesterolemia who are eligible for treatment with HMG-CoA reductase inhibitors.
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PMID:Cost-effectiveness analysis of lipid-modifying therapy in Canada: comparison of HMG-CoA reductase inhibitors in the primary prevention of coronary heart disease. 758 61


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