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Query: UMLS:C0011849 (diabetes)
 277,896 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Maturity-onset diabetes of the young (MODY) is a form of non-insulin-dependent diabetes mellitus characterised by an early age of onset and an autosomal dominant mode of inheritance. Only a proportion of cases are due to mutations in the glucokinase gene. We have studied five Caucasian MODY families, including the first MODY family to be described, with five candidate genes implicated in regulation of insulin secretion. The affected subjects showed more marked hyperglycaemia than that found in subjects with glucokinase mutations. We assessed polymorphic markers close to the genes for glucokinase, hexokinase II, adenosine deaminase, pituitary adenylate cyclase-activating polypeptide receptor, and glucagon-like peptide-1 receptor. Linkage analysis with diabetes gave cumulative log of the odds (LOD) scores of less than -3, implying that mutations in these genes are unlikely to provide a major genetic contribution to this form of MODY.
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PMID:Candidate gene studies in pedigrees with maturity-onset diabetes of the young not linked with glucokinase. 859 19

Because one manifestation of diabetes is an enhancement of the lipolytic process, we evaluated the antilipolytic effects of adenosine A1 agonists in vitro and in vivo in streptozotocin (STZ)-treated diabetic rats. In vitro, we examined the responses to norepinephrine (NE) and adenosine deaminase (ADA), as well as several adenosine A1 agonists, in isolated adipocytes from normal and diabetic rats. Both NE and ADA caused dose-dependent stimulation of lipolysis, elevating glycerol release twofold to threefold over baseline. The sensitivity to both NE and ADA was significantly enhanced in adipocytes from STZ-treated as compared with normal rats. N-5'-ethyl-N(6)(cyclopentyl) adenosine-5'-uronamide (RG14202) was by far the most potent A agonist in inhibiting NE-stimulated lipolysis [50% effective concentration (EC50): 0.014 +/- 0.0008 nM), approximately 1 and 2 log units more potent than N(6)-cyclopentyladenosine (CPA) and N(6)-cyclohexyl-2'-O-methyladenosine (SDZ WAG 994), respectively. In vivo we established a model for evaluating the therapeutic utility of adenosine A1 agonists, emphasizing duration of action. In STZ rats instrumented with telemetry transmitters, the metabolic effects of CPA, RG14202, and SDZ WAG 994 were assessed 6 h after oral administration. Under those conditions, RG14202 and SDZ WAG 994, but not CPA, significantly reduced triglycerides (TRIs) and TRI/free fatty acids (FFAs), respectively. However, all three A1 agonists dose-dependently reduced mean arterial pressure (MAP) and heart rate (HR) concurrently. Thus adenosine A1 agonists can inhibit lipolysis in vitro and in vivo; however, oral administration produces long-lasting beneficial metabolic effects only at doses that also produce a significant bradycardia.
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PMID:Cardiovascular and metabolic effects of adenosine A1-receptor agonists in streptozotocin-treated rats. 912 82

We have previously reported that weekly administration of the adenosine deaminase inhibitor, 2'-deoxycoformycin (dCF), reduces the incidence of insulin-dependent diabetes mellitus (IDDM) in the BB Wistar rat, and this effect is likely due to immunosuppression by dCF. In the present study, we examined the effect of altering the dose and scheduling of dCF on prevention of IDDM in the BB rat. When rats were treated from day 25 of age with 2.5, 4, or 10 mg of dCF/kg/week, the percentage of diabetes-free animals at 120 days of age was 40, 60, and 80% respectively, compared with 10% for control animals, demonstrating increased protection against IDDM with increased dCF dose. Histological assessment of the pancreata from animals that became diabetic revealed a marked mononuclear infiltrate and a loss of positive staining for beta cell granules. In contrast, pancreata from animals that remained diabetes-free appeared normal. Protection against IDDM by dCF was time dependent and only occurred if treatments were initiated by day 30 of age. In addition, the protective effect persisted after drug withdrawal. Further studies are required to determine the optimum duration of therapy with dCF to prevent IDDM and to examine the immunological mechanism responsible for this effect.
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PMID:Immunotherapy for insulin-dependent diabetes mellitus in the "BB" rat. 921 88

Several candidate genes for non-insulin-dependent diabetes mellitus (NIDDM) map on chromosome 20, including the phosphoenolpyruvate carboxykinase gene (PCK1) and one of the maturity onset diabetes of the young genes (MODY1). Thus, we have investigated the entire long arm of chromosome 20. Linkage analyses were conducted in a total sample of 148 NIDDM families (301 NIDDM sib pairs) and in a subset of 42 early onset NIDDM families, where genetic components are likely to play a more important role (55 NIDDM sib pairs diagnosed at or before 45 years of age), using 10 highly polymorphic markers with an average map density of 7.5 cM. Using affected sib pair methods (two-point linkage and multipoint linkage analyses), significant results were obtained with the 20q13 region, in the vicinity of the PCK1 locus, only in the subset of 55 early onset NIDDM sib pairs (multipoint MLS = 2.74, P = 0.0004; MLS = 2.34, P = 0.0009 when using a conservative weighting procedure). Moreover, another region spanning the ribophorin II (RPNII, phospholipase C (PLC1) and adenosine deaminase (ADA) loci suggested linkage with NIDDM (multipoint MLS of 1.81 in all NIDDM sib pairs, P = 0.003; MLS = 1.31, P = 0.012 when using a conservative weighting procedure). Whereas our study suggests the location of a susceptibility locus for early onset NIDDM in the PCK1 gene region, further investigation in larger data sets is required to confirm these results and assess the role of other regions on chromosome 20q in human NIDDM.
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PMID:A susceptibility locus for early-onset non-insulin dependent (type 2) diabetes mellitus maps to chromosome 20q, proximal to the phosphoenolpyruvate carboxykinase gene. 928 75

We present a girl with severe combined immunodeficiency (SCID) from adenosine deaminase (ADA) deficiency who developed insulin dependent diabetes mellitus (IDDM). This combination of features has not been previously reported. Because HLA typing (DQbeta-57 Asp/Asp and DQalpha-52 Ser/Ser) showed no alleles usually associated with IDDM, and ICA were repeatedly negative even after treatment with PEG-ADA and gene transplant, hypotheses on the pathogenesis of diabetes mellitus in this patient are discussed.
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PMID:A girl with diabetes and severe combined immunodeficiency from adenosine deaminase deficiency. 936 70

Effect of alloxan induced diabetes on the activity of adenosine deaminase (ADA) was studied in the liver, spleen, stomach and small intestine of mice at two different postnatal ages (preweaned, 15-day and postweaned, 60-day). Alloxan significantly stimulates (133%) ADA activity in the liver of 15-day old mice, while it has no significant effect in the 60-day old animals. In contrast, ADA activity was moderately increased (25%) in spleen of both the ages. However, no significant influence of alloxan was observed on ADA activity of stomach at either age of mice. On the other hand, alloxan treatment increases (69%) intestinal ADA activity in 15-day old mice, with no significant change in 60-day old animals. Thus, alloxan diabetes increases ADA activity in an age- and tissue-specific manner. Stimulation of ADA activity in diabetic mice might play role in immune and other metabolic dysfunctions in diabetic conditions.
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PMID:Alloxan diabetes regulates adenosine deaminase activity in mice: tissue- and age-specific correlation. 978 39

Adenosine in the extracellular space modulates stimulated glucose transport in striated muscle. In the heart and in adipocytes, adenosine potentiates insulin-stimulated glucose transport. There is controversy regarding the effect of adenosine in skeletal muscle, with reports of both an inhibitory effect and no effect, on insulin-stimulated glucose transport. We found that, in rat epitrochlearis and soleus muscles, removing adenosine with adenosine deaminase or blocking its action with the adenosine receptor blocker CPDPX markedly reduces the responsiveness of glucose transport to stimulation by 1) insulin alone, 2) contractions alone, and 3) insulin and contractions in combination. Measurement of the increase in GLUT4 at the cell surface in response to a maximally effective insulin stimulus in the epitrochlearis muscle, using the exofacial label ATB-[3H]BMPA, showed that adenosine deaminase treatment markedly reduces cell-surface GLUT4 labeling. The reduction in cell-surface GLUT4 labeling was similar in magnitude to the decrease in maximally insulin-stimulated glucose transport activity in adenosine deaminase-treated muscles. These results show that adenosine potentiates insulin- and contraction-stimulated glucose transport in skeletal muscle by enhancing the increase in GLUT4 at the cell surface and raise the possibility that decreased adenosine production or action could play a causative role in insulin resistance.
Diabetes 1998 Nov
PMID:Removal of adenosine decreases the responsiveness of muscle glucose transport to insulin and contractions. 979 34

We studied 273 subjects with non-insulin-dependent diabetes mellitus (NIDDM) from the population of Penne, Italy. A low proportion of the adenosine deaminase (ADA)*2 allele is observed in NIDDM subjects with a body mass index (BMI) of 25 kg/m2 or less. On the contrary, a high proportion of this allele is observed in NIDDM patients with a BMI higher than 34 kg/m2. In the intermediate BMI class, the proportion of ADA*2 alleles does not differ significantly from that of normal subjects from the same population. No significant effect on the relation between ADA and BMI has been observed for the following variables: sex, age at the time of study, age at onset, therapy with insulin, and dyslipidemia. A borderline effect has been observed for the duration of disease. Several lines of experimental evidence suggest that an excess of adenosine A1 receptor activity may contribute to adiposity in NIDDM. ADA is a polymorphic enzyme that irreversibly deaminates adenosine to inosine, contributing to the regulation of intracellular and extracellular concentrations of adenosine. Since the activity of genotypes carrying the ADA*2 allele is lower than that of the more common genotype ADA*1/*1, genetic variability of the enzyme could contribute to degree of obesity in NIDDM. Our data also support attempts to ameliorate the metabolic control of diabetes through pharmacological modulation of adenosine receptors.
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PMID:Adenosine deaminase and body mass index in non-insulin-dependent diabetes mellitus. 1045 55

Adipocyte glucose transport can be impaired by prolonged hyperglycemic conditions. However, at the whole body level, lipolysis is quantitatively a more important function of adipocytes than glucose uptake. We have therefore investigated the effect of prolonged high glucose and insulin on adipocyte lipolysis in basal conditions or with maximal concentrations of adenosine deaminase (ADA), dibutyryl cyclic-AMP (dbcAMP), or isoproterenol (ISO). Neither insulin nor glucose alone affected basal or maximally stimulated lipolysis. However, insulin plus glucose increased the rate of ADA-, dbcAMP-, and ISO-stimulated lipolysis by 40-65%, and the effect was maximal by 8 h. When insulin was kept constant, the half-maximally effective concentration (EC50) of glucose was approximately 2.5 mmol/l. We also demonstrated that the effect is not glutamine-dependent and does not induce insulin resistance of lipolysis. Because the effect of insulin and glucose was evident whether lipolysis was stimulated by ADA, dbcAMP, or ISO, we hypothesized that the expression of the rate-limiting enzyme for lipolysis, hormone-sensitive lipase (HSL), was increased. Our results show that insulin plus glucose-treated cells contain approximately 40% more HSL protein than control cells, in good agreement with the increase in maximally stimulated lipolysis. We conclude that hyperglycemic-hyperinsulinemic conditions increase basal and maximal adipocyte lipolysis by a mechanism that is not glutamine-dependent and involves maintenance of cellular concentrations of HSL. The results also provide evidence that factors other than translocation of HSL to the lipid droplet are necessary to activate the enzyme.
Diabetes 1999 Sep
PMID:Long-term regulation of lipolysis and hormone-sensitive lipase by insulin and glucose. 1048 May 96

Adenosine has been implicated as an important endogenous regulator of various tissue functions. In diabetes, the responsiveness of several tissues to adenosine is altered. The aim of this study was to investigate the activities of enzymes metabolizing adenosine in tissues of diabetic rats. The cytosolic activity (V(max)) of adenosine kinase (AK) was decreased by 50% in the kidney and by 40% in the heart and liver of diabetic rats. A decrease in the V(max) of AK in diabetic tissues was not associated with a change in the K(m) for adenosine. Evaluation of AK gene transcript status showed significantly lower levels of AK mRNA in diabetic tissues as compared to normal tissues. In diabetic kidneys, the level of AK gene transcript was lowered by 50% on first day after streptozotocin administration, and these reduced levels were sustained declined during the next 10 days. Smaller changes in AK gene transcript levels were observed in the heart and liver than in the kidney. The cytosolic activities of 5'-nucleotidase, AMP deaminase, and adenosine deaminase were unchanged in kidney, heart, and liver of diabetic rats. These results suggest that the turnover of the AMP-adenosine metabolic cycle might be impaired in diabetic tissues due to the reduced activity of adenosine kinase.
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PMID:Decreased expression of adenosine kinase in streptozotocin-induced diabetes mellitus rats. 1068 43


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