Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011854 (type 1 diabetes)
 20,749 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In pregnant women with type 1 diabetes, suboptimal glucose control in the first trimester is a strong predictor for giving birth to a large fetus. However, the mechanisms underlying this association are unknown. We hypothesized that transient hyperglycaemia in early pregnancy results in (1) increased placental growth and (2) an up-regulation of placental nutrient transport capacity, which leads to fetal overgrowth at term. In order to test this hypothesis, pregnant rats were given intraperitoneal injections of glucose (2 g kg(-1), resulting in a 50-100% increase in blood glucose level during 90 min) or saline (control) in either early or late gestation using four different protocols: one single injection on gestational day (GD) 10 (n=5), three injections on GD 10 (n=8-9), six injections on GD 10 and 11 (n=9-11) or three injections on GD 19 (n=7-8). Multiple injections were given approximately 4 h apart. Subsequently, animals were studied on GD 21. Three glucose injections in early pregnancy significantly increased placental weight by 10%, whereas fetal weight was found to be increased at term in response to both three (9% increase in fetal weight, P<0.05) and six glucose injections (7%, P=0.05) in early gestation. A single glucose injection on GD 10 or three injections of glucose on GD 19 had no effect on placental or fetal growth. In groups where a change in feto-placental growth was observed, we measured placental system A and glucose transport activity in the awake animals on GD 21 and placental expression of the glucose and amino acid transporters GLUT1, GLUT3, SNAT2 (system A), LAT1 and LAT 2 (system L). Placental system A transport at term was down-regulated by six glucose injections in early pregnancy (by -33%, P<0.05), whereas placental mRNA and protein levels were unchanged. No long-term alterations in maternal metabolic status were detected. In conclusion, we demonstrate that transient hyperglycaemia in early pregnancy is sufficient to increase fetal weight close to term. In contrast, brief hyperglycaemia in late pregnancy did not stimulate fetal growth. Increased fetal growth may be explained by a larger placenta, which would allow for more nutrients to be transferred to the fetus. These data suggest that maternal metabolic control in early pregnancy is an important determinant for feto-placental growth and placental function throughout the remainder of gestation. We speculate that maternal metabolism in early pregnancy represents a key environmental cue to which the placenta responds in order to match fetal growth rate with the available resources of the mother.
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PMID:Brief hyperglycaemia in the early pregnant rat increases fetal weight at term by stimulating placental growth and affecting placental nutrient transport. 1743 Sep 88

Heart consumes more energy than any other organ. It can utilize various metabolic substrates as a source of energy. The primary substrates are free fatty acids, especially long-chain fatty acids and glucose. The lipid bilayer of plasmalemma is impermeable for glucose. Therefore, glucose transport across the plasma membrane is mediated via glucose transporters. In human, cardiac cells are expressed as 2 families of glucose transporters: GLUTs and SGLTs. These transport proteins are GLUT1, GLUT3, GLUT8, GLUT10, GLUT11, GLUT12 and SGLT1. In human heart, GLUT4 is the major isoform that represents approximately 70% of the total glucose transporters. The changes observed in diabetic heart showed that type 1 diabetes mellitus alters the expression and translocation of GLUT4 and GLUT8 in the atria. In diabetic atria, the content in cell surface of these glucose transporters is downregulated. Expression of SGLT1, is increased in patients with end-stage cardiomyopathy secondary to type 2 diabetes. Increased expression of SGLT1 is a compensatory mechanism to the reduction in cardiac GLUT1 and GLUT4 expression. In animal model of type 1 diabetes, the expression of Sglt1 transporter is significantly decreased, and in the animal model of type 2 diabetes it is significantly increased. In heart diseases, such as cardiac hypertrophy (that is similar to fetal heart), heart failure and myocardial ischemia different perturbations in expression of glucose transporters are observed, especially in GLUT1 and GLUT4, due to changes in heart glucose metabolism. In this article, the functions of glucose transporters in healthy heart and in cardiac diseases are reviewed.
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PMID:Glucose transporters in healthy heart and in cardiac disease. 2803 63

Patients with type 1 diabetes mellitus (T1DM) have increased thrombosis and platelet activation. The mechanisms for platelet hyperactivation in diabetes are incompletely understood. T1DM is accompanied by hyperglycemia, dyslipidemia, and increased inflammation in addition to an altered hormonal milieu. In vitro analysis of platelets revealed that normal glucose reduces platelet activation whereas hyperglycemic conditions increase platelet activation. We therefore hypothesized that hyperglycemia increases platelet glucose utilization, which increases platelet activation to promote thrombosis. Glucose uptake and glycolysis were increased in platelets isolated from mice given streptozotocin (STZ) to induce T1DM in concert with induction of GLUT3. Platelets from STZ-induced diabetic mice exhibited increased activation after administration of protease-activated receptor 4 peptide and convulxin. In contrast, platelets isolated from GLUT1 and GLUT3 double-knockout (DKO) mice, which lack the ability to use glucose, failed to increase activation in hyperglycemic mice. Diabetic mice displayed decreased survival in a collagen/epinephrine-induced pulmonary embolism model of in vivo platelet activation relative to nondiabetic controls. Survival after pulmonary embolism was increased in diabetic DKO mice relative to nondiabetic controls. These data reveal that increased platelet glucose metabolism in vivo contributes to increased platelet activation and thrombosis in a model of T1DM.
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PMID:Glucose Metabolism Is Required for Platelet Hyperactivation in a Murine Model of Type 1 Diabetes. 3076 35

Diabetes-induced hyperglycemia has a direct damaging effect on ovarian function. Despite its deadly impact on ovaries, the mechanism of this condition has not been fully elucidated. Glucose transporters are involved in glucose uptake and utilization. Many transporters have been detected in the ovaries, but their roles in diabetes-induced ovarian impairment are still unclear. In this study, the goal is to analyze glucose transporter expression in the ovarian follicles of type 1 diabetes mellitus patients and determine their roles within ovarian function impairment. The ovarian function of a mouse model of type 1 diabetes mellitus was evaluated by observing its estrus cycle, follicular development, and ovulation. Subtypes of the glucose transporter (GLUT2, GLUT3, GLUT4, SGLT1, and SGLT2), adenosine monophosphate-activated protein kinase (AMPK), and phosphorylated AMPK (Thr172) were found to be simultaneously present in follicle cells. Compared with nondiabetic control mice, the diabetic mice showed a dysregulated estrus cycle and a significantly higher number of abnormal ova. Furthermore, the expression of multiple glucose transporters was lower than that of phosphorylated AMPK. Phosphorylated AMPK possessed more follicular granulosa cells and oocytes of diabetic mice than in those of the control mice. These results suggest that diabetes-induced hyperglycemia reduces the capability of ovarian follicle cells by downregulating glucose transporter expression, causing decreased glucose uptake and energy deprivation. This impact can potentially impair egg maturation and ovulation.
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PMID:Changes in Expression of Follicular Glucose Transporters May Be Involved in Ovarian Function Impairment during Diabetic Hyperglycemia. 3188 30