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)

Gluconeogenesis is increased in NIDDM. We therefore examined the metabolism of glutamine and alanine, the most important gluconeogenic amino acids, in 14 postabsorptive NIDDM subjects and 18 nondiabetic volunteers using a combination of isotopic ([6-3H]glucose (20 microCi, 0.2 microCi/min), [U-14C]glutamine (20 microCi, 0.2 microCi/min), [3-13C]alanine (99% 13C, 2 mmol, 20 micromol/min), [ring-2H5]phenylalanine (99% 2H, 2 micromol/kg, 0.03 micromol x kg(-1) x min(-1)), and limb balance techniques. Alanine turnover (4.54 +/- 0.24 vs. 5.64 +/- 0.33 micromol x kg(-1) x min(-1)), de novo synthesis (3.00 +/- 0.25 vs. 4.01 +/- 0.33 micromol x kg(-1) x min(-1)), and conversion to glucose (1.02 +/- 0.09 vs. 1.56 +/- 0.17 micromol x kg(-1) x min(-1)) were increased in NIDDM subjects (all P < 0.01), while its forearm release (0.45 +/- 0.04 vs. 0.39 +/- 0.04 micromol x kg(-1) x min(-1)) was unaltered. Although glutamine turnover (4.81 +/- 0.23 vs. 4.40 +/- 0.31 micromol x kg(-1) x min(-1)) was unaltered in NIDDM, its conversion to glucose (0.57 +/- 0.04 vs. 1.08 +/- 0.10 micromol x kg(-1) x min(-1)) and to alanine (0.10 +/- 0.01 vs. 0.34 +/- 0.04 micromol x kg(-1) x min(-1)) (both P = 0.001) was increased while its oxidation (2.84 +/- 0.27 vs. 1.84 +/- 0.15 micromol x kg(-1) x min(-1), P = 0.03) and forearm release (0.77 +/- 0.05 vs. 0.62 +/- 0.09 micromol x kg(-1) x min(-1), P < 0.008) were both reduced. Our results thus demonstrate that there are substantial alterations of glutamine and alanine metabolism in NIDDM. Conversion of both amino acids to glucose and the proportion of their turnover used for gluconeogenesis are increased; release of both amino acids from tissues other than skeletal muscle seems to be increased. Finally, the reduction in glutamine oxidation, possibly the result of competition with glucose and free fatty acids as fuels, makes more glutamine available for gluconeogenesis without a change in its turnover.
Diabetes 1996 Jul
PMID:Glutamine and alanine metabolism in NIDDM. 866 34

Diabetics are prone to infection, in part, due to neutrophil dysfunction and impaired superoxide generation. The mechanism of impaired superoxide generation in diabetes remains unknown. We report herein that neutrophils from poorly controlled diabetics have impaired ability to generate superoxide in response to N-formyl-Met-Leu-Phe (FMLP) but not to 4 beta-phorbol 12-myristate 13-acetate (PMA). Phosphatidic acid, a phospholipase D (PLD) -mediated product of membrane phosphatidylcholine is decreased in response to FMLP. The impaired superoxide generation and activation of phospholipase D are readily reversible once the diabetic neutrophils are incubated in normal glucose concentration. These data show that decreased superoxide generation by neutrophils in insulin-dependent diabetics is, in part, due to impaired activation of phospholipase D and is solely due to high glucose concentrations.
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PMID:Inhibition of phospholipase D and superoxide generation by glucose in diabetic neutrophils. 869 36

Since the insulin receptor substrate-1 (IRS-1) is the major substrate of the insulin receptor tyrosine kinase and has been shown to activate phosphatidylinositol (PI) 3-kinase and promote GLUT4 translocation, the IRS-1 gene is a potential candidate for development of non-insulin-dependent diabetes mellitus (NIDDM). In this study, we have identified IRS-1 gene polymorphisms, evaluated their frequencies in Japanese subjects, and analysed the contribution of these polymorphisms to the development of NIDDM. The entire coding region of the IRS-1 gene of 94 subjects (47 NIDDM and 47 control subjects) was screened by polymerase chain reaction-single stranded conformation polymorphism (PCR-SSCP) analysis. Seven SSCP polymorphisms were identified. These corresponded to two previously identified polymorphisms [Gly971 --> Arg (GGG --> AGG) and Ala804 (GCA --> GCG)] as well as five novel polymorphisms [Pro190 --> Arg (CCC --> CGC), Met209 --> Thr (ATG --> ACG), Ser809 --> Phe (TCT --> TTT), Leu142 (CTT --> CTC), and Gly625 (GGC --> GGT)]. Although the prevalence of each of these polymorphisms was not statistically different between NIDDM and control subjects, the prevalence of the four IRS-1 polymorphisms with an amino acid substitution together was significantly higher in NIDDM than in control subjects (23.4 vs 8.5%, p < 0.05), and two substitutions (Met 209 --> Thr and Ser809 --> Phe) were found only in NIDDM patients. Equilibrium glucose infusion rates during a euglycaemic clamp in NIDDM and control subjects with the IRS-1 polymorphisms decreased by 29.5 and 22.0%, respectively on the average when compared to those in comparable groups without polymorphisms, although they were not statistically significant. Thus, IRS-1 polymorphisms may contribute in part to the insulin resistance and development of NIDDM in Japanese subjects; however, they do not account for the major part of the decrease in insulin-stimulated glucose uptake which is observed in subjects with clinically apparent NIDDM.
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PMID:Molecular scanning of the insulin receptor substrate-1 (IRS-1) gene in Japanese patients with NIDDM: identification of five novel polymorphisms. 873 21

Friedreich ataxia (FA) is associated with the expansion of a GAA trinucleotide repeat in the first intron of the X25 gene. We found both alleles expanded in 67 FA patients from 48 Italian families. Five patients from three families were compound heterozygotes with expansion on one allele and an isoleucine-->phenylalanine change at position 154 on the other one. We found neither expansions nor point mutations in three patients. The length of FA alleles ranged from 201 to 1,186 repeat units, with no overlap with the normal range, and showed a negatively skewed distribution with a peak between 800 and 1,000 repeats. The FA repeat showed meiotic instability with a median variation of 150 repeats. The lengths of both larger and smaller alleles in each patient inversely correlated with age at onset of the disorder. Smaller alleles showed the best correlation, accounting for approximately 50% of the variation of age at onset. Mean allele length was significantly higher in patients with diabetes and in those with cardiomyopathy.
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PMID:The relationship between trinucleotide (GAA) repeat length and clinical features in Friedreich ataxia. 875 56

It has been a long established principle in the treatment of diabetes that the patient or his/her family is responsible for day-to-day monitoring of metabolic control. It is believed that this concept should also now be applied in phenylketonuria. At present, self-monitoring of blood phenylalanine still requires assaying the phenylalanine concentration in capillary blood obtained by finger-stick sampling at home, via mailing to a nearby laboratory. Frequently and rapidly obtained data can guide the patient to adjust dietary phenylalanine intake, provided he and his family have been informed in detail about the disease and trained in practical diet competence. Teaching programmes for patients are to be promoted. A home-monitoring device for blood phenylalanine is at the development stage.
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PMID:Towards self-monitoring and self-treatment in phenylketonuria--a way to better diet compliance. 882 23

Phenylalanine hydroxylase catalyzes the major regulatory step of the phenylalanine degradation pathway. In view of the glucogenic nature of phenylalanine breakdown, and hence its potential contribution to glucose homeostasis, we have investigated the impact of streptozotocin-induced diabetes upon the expression of rat phenylalanine hydroxylase. Northern blot analysis revealed that induction of diabetes was associated with an increase in the in vivo abundance of hepatic phenylalanine hydroxylase-specific mRNA. This increase in mRNA abundance was maintained for at least 8 hr in liver cells isolated from diabetic animals. In contrast, phenylalanine hydroxylase immunoreactivity and enzymic activity decreased, over the 8 hr incubation period, to levels similar to those observed in liver cells from normal animals. These changes were retarded, but not prevented, by the presence of dexamethasone in incubation media. In liver cells from normal animals the abundance of phenylalanine hydroxylase-specific mRNA, immunoreactivity and enzymic activity, were largely insensitive to treatment with dexamethasone and/or glucagon over an 8 hr incubation period. It is concluded that, whereas diabetes-related alterations in phenylalanine hydroxylase-specific mRNA abundance persist after isolation of liver cells, changes in phenylalanine hydroxylase protein abundance do not. Additionally, in contrast to certain other enzymes (e.g. phosphoenolpyruvate carboxykinase) it is not possible to mimic diabetes-related alterations in the expression of phenylalanine hydroxylase, in liver cells from normal animals, by simple hormonal manipulation of incubation media. This implies that other additional factors must also contribute to diabetes-related alterations in hepatic enzyme expression.
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PMID:Differential effects of streptozotocin-induced diabetes on phenylalanine hydroxylase protein and mRNA abundance in isolated rat liver cells. 892 6

To evaluate whether granulocyte-colony stimulating factor (G-CSF) improves an impaired production of oxygen-derived free radicals by neutrophils from poorly controlled NIDDM patients, we studied the effect of G-CSF on myeloperoxidase (MPO) activity and chemiluminescence amplified by a Cypridina luciferin analog (CLA-DCL), which is dependent on O2 generation, and luminol (L-DCL), which is dependent on OCl(-) generation, in response to formyl-methonyl-leucyl-phenylalanine. Both CLA-DCL and L-DCL by neutrophils from the diabetic group (n = 15, HbA(1c) >10%) were significantly decreased (26 and 37%, respectively: P < 0.01) compared with the age-matched normal control group (n = 15), and L-DCL was more sensitive to this inhibition than CLA-DCL (P < 0.05). In both control and diabetic neutrophils, G-CSF significantly enhanced both CLA-DCL (175% in control and 156% in diabetic) and L-DCL (283% in control and 346% in diabetic). In diabetic neutrophils, the enhancing effect of G-CSF on L-DCL was more sensitive than on CLA-DCL (P < 0.001). There was a positive correlation between HbA(1c) and the enhancing effect of G-CSF on L-DCL in diabetic patients (P < 0.05), but not on CLA-DCL. MPO activity was also decreased in the diabetic group (63%, P < 0.05), and G-CSF improved this impaired MPO activity (184%, P < 0.01). Furthermore, there was a positive correlation between HbA(1c) and the improving effect of G-CSF on MPO activity (P < 0.05). Because bacterial infection still accounts for an important cause of morbidity and mortality in diabetic patients, these data suggest that G-CSF may be useful as a drug to prevent the aggravation of bacterial infection by improving neutrophil function, especially through H2O2-MPO-OCl(-) mechanism, in poorly controlled diabetic patients.
Diabetes 1997 Jan
PMID:Effect of granulocyte-colony stimulating factor on generation of oxygen-derived free radicals and myeloperoxidase activity in neutrophils from poorly controlled NIDDM patients. 897 Oct 93

1. The properties of L-arginine transport have been characterized and correlated with cGMP production (index of nitric oxide (NO)) in whole gastric glands isolated from non-diabetic and alloxan-diabetic rabbits. 2. In non-diabetic and diabetic glands, transport of L-arginine was stereoselective, Na+ and pH independent and inhibited by other cationic amino acids. L-Arginine transport was slightly inhibited by L-leucine and L-phenylalanine, but unaffected by other neutral amino acids. 3. Diabetes enhanced the Vmax for saturable L-arginine transport from 10.7 +/- 1.0 to 17.7 +/- 0.5 pmol (mg protein)-1 s-1, with negligible changes in K(m). 4. Accumulation of the membrane potential-sensitive probe tetra[3H]phenylphosphonium (TPP+) was increased 2-fold in diabetic compared with non-diabetic gastric glands, suggesting a membrane hyperpolarization. 5. Basal intracellular cGMP levels were elevated 2-fold in diabetic gastric glands, and in non-diabetic glands histamine, vasoactive intestinal peptide, and bradykinin increased cGMP levels. The NO synthase inhibitor NG-nitro-L-arginine methyl ester (100 microM) abolished basal cGMP accumulation. 6. Addition of extracellular L-arginine induced a concentration-dependent increase in cGMP levels in gastric glands isolated from non-diabetic rabbits, but had no effect on elevated cGMP levels in diabetic glands. 7. Insulin induced a rapid (5 min) concentration-dependent increase in cGMP levels in non-diabetic gastric glands, but reduced elevated cGMP levels in diabetic gastric glands. 8. The present study has identified a specific transport system for L-arginine in gastric glands which resembles the classical system y+. Our findings also provide the first direct evidence that diabetes increases the basal activity of system y+ and NO synthase in gastric glands. The differential modulation of L-arginine transport by insulin and L-arginine identified in non-diabetic and diabetic glands, may be of importance in protecting the gastric mucosa from injuries associated with diabetes.
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PMID:Diabetes and insulin-induced stimulation of L-arginine transport and nitric oxide synthesis in rabbit isolated gastric glands. 905 89

Adhesion molecule expression on peripheral blood leukocytes from diabetic patients with severe retinopathy and age-matched control subjects was assessed. Expression of CD11b, CD18, and L-selectin was measured on granulocytes and lymphocytes in whole blood within 1 hour of blood collection. Adhesion molecule expression was determined at 4 degrees C, 37 degrees C, and after stimulation with one of the chemotactic peptides, N-formyl-methionyl-leucyl-phenyl-alanine or beta-phorbol 12-myristate 13-acetate. There were no differences between diabetics and controls in CD11b expression in neutrophils at 4 degrees C, 37 degrees C, or after N-formyl-methionyl-leucyl-phenylalanine stimulation. However, during stimulation with beta-phorbol 12-myristate 13-acetate, the increase in CD11b expression in neutrophils from patients with diabetes was significantly less than in controls. In neutrophils, there was no difference between the control and diabetic participants in CD18 expression at 4 degrees C, but after warming the cells to 37 degrees C, the expression was significantly higher in patients with diabetes. The difference became even more apparent after N-formyl-methionyl-leucyl-phenyl-alanine stimulation. The increase in CD18 expression after beta-phorbol 12-myristate 13-acetate stimulation of neutrophils was similar in control and diabetic participants. There was no difference in L-selectin expression in neutrophils under any conditions. There was no difference in adhesion molecule expression on lymphocytes under similar conditions. In summary, these observations indicate that integrin expression of neutrophils from patients with diabetes and retinopathy is altered after stimulation with neutrophil-activating agents. The changes were integrin-, stimulus-, and cell-specific, which suggests that the signal transduction mechanisms may be altered in diabetic neutrophils. These alterations may be responsible for abnormal leukocyte/endothelial interactions and microvascular complications in diabetic retinopathy.
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PMID:Alterations in stimulus-induced integrin expression in peripheral blood neutrophils of patients with diabetic retinopathy. 907 29

Cathepsin A activity assayed with N-Cbz-Phe-Ala, N-Cbz-Glu-Tyr and N-Cbz-Glu-Phe as substrates, was measured in fresh corneas, lenses, aqueous humor, vitreous humor and choroid plus retinal pigment epithelium taken from normal bovine eye balls and in human intraocular fluids from the eye balls in various ocular diseases (cataract, glaucoma, diabetes, intraocular tumors). Cathepsin A exhibited a pH optimum at 5.0 and showed the highest specificity towards N-Cbz-Phe-Ala as a substrate. In bovine ocular tissues high cathepsin A activity was found in the choroid plus retinal pigment epithelium and in cornea. The lens and the vitreous humor showed low enzyme activity and the aqueous humor none at all. In the human aqueous humor of the eye with cataract cathepsin A activity was more than three times higher then in the eye with choroid tumor. In human vitreous humor in absolute glaucoma the activity was twice as high as in melanoma and almost three times higher than in the case of lung metastatic tumor. Diabetes in glaucoma increased seven fold cathepsin A activity in the vitreous humor.
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PMID:Cathepsin A activity of normal bovine ocular tissues and pathological human intraocular fluids. 910 5


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