Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011860 (type 2 diabetes)
 57,723 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have examined insulin binding, and insulin receptor associated tyrosine kinase activity in detergent solubilized and Ricin II-agarose purified receptor preparations from erythrocytes of obese and non-obese subjects with normal glucose tolerance and non-obese patients with NIDDM. Insulin receptor activity, as assessed by [125I Tyr A14] insulin binding, was significantly lower in erythrocyte preparations from the obese group when compared with similar preparations from non-obese subjects, with either normal glucose tolerance or NIDDM. The affinity of the receptor for insulin, however, was reduced in both obese subjects and patients with NIDDM as compared to non-obese subjects with normal glucose tolerance. Insulin receptor tyrosine kinase activity, measured in the absence (basal) and presence of insulin (0.3-3000 nM), was decreased in obese and NIDDM subjects with normal glucose tolerance and in patients with NIDDM. Insulin sensitivity, measured as the dose of insulin required for half-maximal activation of kinase activity, however, was comparable among three groups. In contrast, insulin-stimulated tyrosine kinase activity, when normalized to insulin binding activity, was unchanged in both non-obese and obese subjects with normal glucose tolerance, but was reduced approximately 60% in the NIDDM group. These findings indicate that the functional behavior of insulin receptor-kinase signaling system is markedly impaired in non-obese patients with NIDDM. Furthermore, the insulin receptor-tyrosine kinase defect (i.e. decrease in activity) observed in patients with NIDDM is probably related to a reduction in coupling efficiency between insulin binding and the activation of the receptor tyrosine kinase activity.
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PMID:Insulin-receptor tyrosine kinase activity is decreased in erythrocytes from non-obese patients with NIDDM. 792 91

Insulin receptor is a membrane-bound glycoprotein playing a key role in transmembrane signaling of insulin. Therefore, it is logical to look for abnormal structure or functions of this protein in insulin resistance syndromes, such as major insulin resistance syndromes and non insulin dependent diabetes mellitus. Cloning of the insulin receptor cDNA allowed to identify the functional domains of the protein (insulin binding site, autophosphorylation sites and tyrosine-kinase domain). Mutations of the insulin receptor gene are often observed in rare syndromes of major insulin resistance, such as leprechaunism, type A insulin resistance and Rabson-Mendenhall syndrome. However, such studies are disappointing in the case of NIDDM, in which defects of other proteins involved in insulin action should be investigated.
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PMID:[Insulin receptor and diabetes]. 793 36

We reviewed 23 Japanese patients with mutation in the insulin receptor gene. In general, patients with two mutant alleles tend to be more severely insulin-resistant than those with one mutant allele. Most of the mutations have been identified in patients with genetic syndromes associated with extreme insulin resistance. However, some patients having a mutation in the insulin receptor gene (especially in the tyrosine kinase domain), were moderately insulin-resistant. In these cases, despite having a same mutation in the insulin receptor gene, some individuals exhibited significant clinical differences (e.g. insulin resistance or glucose tolerance). Although mutations in the insulin receptor gene can cause insulin resistance, we assume that other genetic or behavioral factors may alter the clinical phenotype in patients with same mutations in the insulin receptor gene. Nevertheless, mutations in the insulin receptor gene may be a contributory cause of insulin resistance in a subpopulation (approximately 1%) of NIDDM.
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PMID:[Insulin receptor gene in an etiology of Japanese NIDDM]. 798 3

The effect of a physical training course of 1-2 month duration using cycloergometer with the intensity of VO2 max 60%, 30 min per day was observed in non-insulin dependent diabetes mellitus (NIDDM) patients. The results showed a decrease of plasma glucose and insulin levels, sigma PG and sigma IRI and an improvement of blood lipid constitution. These were accompanied by a decreased erythrocyte insulin receptor binding rate and a reduction of receptor binding sites of both high and low affinity receptors.
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PMID:Exercise therapy of non-insulin dependent diabetes mellitus a report of 10 year studies. The efficacy of exercise therapy. 803 9

A14-125I-monoiodoinsulin binding to, internalization into, and degradation inside human circulating monocytes, a cell type widely used for insulin receptor studied, from normal(32) and weight, age-matched NIDDM(31) subject were studied. The specific insulin binding, internalization and degradation were decreased in the cells from NIDDM compared to that in the cells from normal subjects. Scatchard plot analysis of these group data reveal that cells from the normal control subject contain 28,000 receptor sites per cell, while monocytes from the NIDDM patients contain 15,000 sites per cell. These results indicate that the decreased abilities of insulin binding, internalization and degradation of target cells may play a role in the cellular resistance to insulin that occurs in the NIDDM.
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PMID:[Defects in insulin binding, internalization and degradation of monocytes from patients with non-insulin-dependent diabetes mellitus]. 803 59

Current methods for the screening and diagnosis of glucose intolerance first discovered in pregnancy are reviewed and innovative approaches to the detection of metabolic disturbances in pregnancy are presented. Glucose intolerance first detected in pregnancy, termed gestational diabetes mellitus (GDM), is amongst the most significant risks of adverse fetal and maternal outcome. Normal pregnancy is characterized by both insulin resistance and pancreatic B cell compensation. In those pregnancies complicated by glucose intolerance reflected in hyperglycemia, insulin resistance appears to be heightened, both blood flow and transcapillary transport of insulin are compromised and insulin receptor and post receptor defects are exacerbated. The resulting hyperinsulinemia and hyperglycemia have, in turn, been associated with accumulated maternal fat deposition and fetal macrosomia. This cascade of events constitutes GDM or impaired glucose tolerance. The discovery of GDM is made through a process of screening and diagnosis, employing standardized oral glucose challenge tests. These tests were designed to identify those women at risk for subsequent development of non-insulin dependent diabetes mellitus. The current efficacy of glucose challenge tests has been questioned in light of increasing concern over their usefulness in detecting those women at risk for maternal and fetal complications of pregnancy. Alternative methods, including both the modification of the standardized tests, as well as the introduction of newer methodologies, such as capillary blood glucose monitoring, have been proposed. The implementation of newer approaches may result in improved detection of those women whose infants are at high risk for both metabolic and morphologic complications of persistent hyperglycemia in pregnancy.
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PMID:Detection of glucose intolerance in pregnancy. 822 93

Sulfonylurea drugs are widely used in the therapy of NIDDM. The improvement of glucose tolerance after long-term treatment of NIDDM patients with the drug can be explained by stimulation of glucose utilization in peripheral tissues that are characterized by insulin resistance in these patients. We studied whether the novel sulfonylurea drug, glimepiride, stimulates glucose transport into isolated insulin-resistant rat adipocytes. After long-term incubation of the cells in primary culture with high concentrations of glucose, glutamine, and insulin, stimulation of glucose transport by insulin was significantly reduced both with respect to maximal responsiveness (65% decrease of Vmax) and sensitivity (2.6-fold increase of ED50) compared with adipocytes cultured in medium containing a low concentration of glucose and no insulin. This reflects insulin resistance of glucose transport. In contrast, both responsiveness and sensitivity of glucose transport toward stimulation by glimepiride were only marginally reduced in insulin-resistant adipocytes (15% decrease of Vmax; 1.2-fold increase of ED50) versus control cells. Glimepiride, in combination with glucose and glutamine during the primary culture, caused desensitization of the glucose transport system toward stimulation by insulin, but to a lesser degree than insulin itself (50% reduction of Vmax; ninefold increase of ED50). Again, the maximal responsiveness and sensitivity of glucose transport toward stimulation by glimepiride were only slightly diminished. The presence of glimepiride during primary culture did not antagonize the induction of insulin resistance of glucose transport. The stimulation of glucose transport in insulin-resistant adipocytes by glimepiride is caused by translocation of glucose transporters from low-density microsomes to plasma membranes as demonstrated by subcellular fractionation and immunoblotting with anti-GLUT1 and anti-GLUT4 antibodies. Immunoprecipitation of GLUT4 from 32Pi- and [35S]methionine-labeled adipocytes revealed that the insulin resistance of GLUT4 translocation is accompanied by increased (three- to fourfold) phosphorylation of GLUT4 in both low-density microsomes and plasma membranes. Short-term treatment of desensitized adipocytes with glimepiride or insulin reduced GLUT4 phosphorylation by approximately 70 and 25%, respectively, in both fractions. We conclude that glimepiride activates glucose transport by stimulation of GLUT1 and GLUT4 translocation in rat adipocytes via interference at a site downstream of the putative molecular defect in the signaling cascade between the insulin receptor and the glucose transport system induced by high concentrations of glucose and insulin. The molecular site of glimepiride action is related to GLUT4 phosphorylation/dephosphorylation, which may regulate glucose transporter activity and translocation.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:The sulfonylurea drug, glimepiride, stimulates glucose transport, glucose transporter translocation, and dephosphorylation in insulin-resistant rat adipocytes in vitro. 824 32

Insulin action is highly likely to be primarily genetically determined (given a permissive or facilitative environment, for example sufficient calorie availability), as shown by variations in ethnic distribution, evidence for familial transmission and genotypic responses to experimentally induced metabolic stresses. Further, it is likely that the genetic predisposition to insulin resistance is closely linked to (or perhaps synonymous with) the predisposition to develop overt NIDDM. Alternatively, in the development of diabetes, the genetic basis for insulin resistance may be necessary, but not sufficient, requiring a second major gene for beta-cell vulnerability (e.g. exhaustion, deterioration of function, amyloid deposition). The future examination of the genetics of insulin action depends in large measure on the method of assessment of insulin action that is selected and its consistent application to individuals, families and populations. The phenomenological approaches currently being used to describe and define insulin resistance could be identifying many different disorders, all leading to an apparent decrease or impairment of insulin action compared with that in 'normals'. Selection of any method for determining the presence of insulin resistance, together with selection of the threshold for 'present versus absent' is, at best, difficult. It is further complicated by the frequent association of insulin resistance with a wide range of disturbances, including hypertension, dyslipidaemia and glucose intolerance--the insulin resistance 'syndrome'. A number of possible loci and candidate genes controlling insulin action have been studied, and most have been ruled out as the probable underlying cause of the majority of cases of defective insulin action. Among those genes that are unlikely to be determinants of insulin resistance (except in a few rare cases of mutations) are those for insulin, the insulin receptor, glucose transporters and the genes for many specific enzymes. While these are unlikely to be responsible for insulin resistance, such potential genetic defects cannot be fully excluded using present methods. Direct gene sequencing of polymerase-chain-reaction amplified DNA may be the ultimate approach to identifying the critical defects underlying insulin resistance. Other candidate genes regulating insulin action are likely soon to come forth, such as those controlling the generation and function of the intracellular mediators of insulin action.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Genetics of insulin action. 830 12

To study genetic susceptibility to non-insulin dependent diabetes mellitus (NIDDM), association of insulin receptor gene, a candidate gene for NIDDM, with NIDDM was studied. A microsatellite polymorphism located in intron 2 of the human insulin receptor gene was detected by the polymerase chain reaction and used as a genetic marker. Eight different alleles were observed, indicating highly polymorphic nature of this marker. Although no association of this marker with NIDDM was observed in Japanese subjects, this marker will be useful for linkage studies of insulin receptor gene and genes located close to this gene on chromosome 19.
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PMID:A microsatellite polymorphism in the human insulin receptor gene: a highly informative marker for linkage analysis. 834 33

A sensitive microtiter well-based assay for the measurement of insulin activation of insulin receptor kinase in intact human circulating mononuclear cells has been developed and characterized. Mononuclear cells from 100-150 ml blood were incubated with various insulin concentrations to activate the receptor kinase. The cells were then solubilized in the presence of phosphatase and kinase inhibitors and the receptors immobilized to microwells coated with anti-insulin receptor antibody (efficiency of receptor immobilization > 85%). Receptor kinase activity and binding activity were then consecutively measured in the same wells. Insulin incubation of the cells increased the kinase activity three- to fourfold with a half-maximal effect at 5 nM and a maximal effect at 87 nM. In mononuclear cells from 16 subjects with NIDDM, the insulin effect on receptor kinase activation was significantly reduced compared with 16 nondiabetic control subjects (0.135 +/- 0.016 vs. 0.195 +/- 0.024 fmol P.fmol binding activity-1 x min-1, respectively; P < 0.05). We conclude that; 1) it is possible to determine insulin activation of receptor kinase in intact cells in this easily accessible human tissue; 2) insulin activation of insulin receptor kinase is impaired in intact mononuclear cells from patients with NIDDM; and 3) the finding that kinase activation in NIDDM is reduced in a tissue that, according to the literature, contains only the A isoform of the insulin receptor, suggests that mechanisms other than a different abundance of the A and B insulin receptor isoforms must exist that contribute to the decreased kinase activity in NIDDM.
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PMID:A microtiter well assay system to measure insulin activation of insulin receptor kinase in intact human mononuclear cells. Decreased insulin effect in cells from patients with NIDDM. 838 42


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