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)

Insulin-stimulated glucose transport activity and GLUT4 glucose transporter protein expression in rat soleus, red-enriched, and white-enriched skeletal muscle were examined in streptozotocin (STZ)-induced insulin-deficient diabetes. Six days of STZ-diabetes resulted in a nearly complete inhibition of insulin-stimulated glucose transport activity in perfused soleus, red, and white muscle which recovered following insulin therapy. A specific decrease in the GLUT4 glucose transporter protein was observed in soleus (3-fold) and red (2-fold) muscle which also recovered to control values with insulin therapy. Similarly, cardiac muscle displayed a marked STZ-induced decrease in GLUT4 protein that was normalized by insulin therapy. White muscle displayed a small but statistically significant decrease in GLUT4 protein (23%), but this could not account for the marked inhibition of insulin-stimulated glucose transport activity observed in this tissue. In addition, GLUT4 mRNA was found to decrease in red muscle (2-fold) with no significant alteration in white muscle. The effect of STZ-induced diabetes was time-dependent with maximal inhibition of insulin-stimulated glucose transport activity at 24 h in both red and white skeletal muscle and half-maximal inhibition at approximately 8 h. In contrast, GLUT4 protein in red and white muscle remained unchanged until 4 and 7 days following STZ treatment, respectively. These data demonstrate that red skeletal muscle displays a more rapid hormonal/metabolic-dependent regulation of GLUT4 glucose transporter protein and mRNA expression than white skeletal muscle. In addition, the inhibition of insulin-stimulated glucose transport activity in both red and white muscle precedes the decrease in GLUT4 protein and mRNA levels. Thus, STZ treatment initially results in a rapid uncoupling of the insulin-mediated signaling of glucose transport activity which is independent of GLUT4 protein and mRNA levels.
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PMID:Differential regulation of glucose transporter activity and expression in red and white skeletal muscle. 182 59

The purpose of this research was to analyse the change in relationships between the basic carbohydrate and lipid metabolisms parameters in the cardiac muscle and liver in the animals with diabetes, in which the thyroidal hypofunction was evoked additionally. The tests were performed on 43 white rats of the Wistar breed that were subdivided into four groups. The first group were reference animals. The second group were the animals with the evoked thyroidal hypofunction with metizol. The group three rats were injected a single dose of alloxan each in order to evoke diabetes. In group four, diabetes and the thyroidal hypofunction were evoked. The levels of glycogen, lactic and pyruvic acids, cholesterol, free fatty acids, triglycerides and phospholipids were determined in the cardiac muscles and livers of all the animals. It was found that the occurrence of both hormonal disorders, i.e. diabetes and the thyroidal hypofunction, in short time leads to harmful changes in the lipid metabolism of the cardiac muscle and liver and noticeably reduces the glycogen reserve in the liver.
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PMID:[Effect of diabetes and thyroid hypofunction on carbohydrate and lipid metabolism in heart and liver]. 184 28

1. The responses of isolated left atria and papillary muscles to isoprenaline, forskolin and calcium have been examined in 3 week streptozotocin-diabetic rats and the effects of oral ponalrestat administration (25 mg kg-1 daily) on diabetes-induced changes in cardiac responsiveness investigated. 2. Three weeks after animals were made diabetic, cardiac responses to isoprenaline were enhanced and this was accompanied by an increase in the density of ventricular [3H]dihydroalprenolol binding sites. Treatment of animals with ponalrestat prevented the increase in cardiac beta-adrenoceptor responsiveness and receptor number. 3. Diabetes also enhanced the sensitivity of cardiac tissues to forskolin, an effect that was not prevented by the treatment of animals with ponalrestat. 4. Ponalrestat treatment increased the resting and maximum tensions developed by cardiac tissues from diabetic animals and increased the maximum tensions developed by tissues from control animals. Diabetes alone had no effect on resting or maximum developed tensions. 5. Ponalrestat therefore prevents the changes in beta-adrenoceptor density and responsiveness induced by short-term diabetes in the rat and also increases the tension developed by cardiac muscle, an effect observed in diabetic and normal animals.
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PMID:Diabetes-induced changes in cardiac beta-adrenoceptor responsiveness: effects of aldose reductase inhibition with ponalrestat. 184 72

Both exercise training and dietary manipulation (increasing omega-3/omega-6 fat ratio) can ameliorate insulin resistance caused by a high-fat diet in rats. We determined whether alterations in the expression of the insulin-regulatable (IR) and/or HepG2 glucose-transporter (GT) mRNAs were similarly affected. There was a significantly higher level of IRGT mRNA in skeletal muscle from exercise-trained versus sedentary high-fat-fed rats (27% increase, P less than 0.01). This difference is consistent with previously reported increases in muscle insulin-mediated glucose uptake. Skeletal muscle HepG2GT mRNA was too low to detect any training effect, but there was a tendency toward higher levels with training in cardiac muscle. In contrast, dietary manipulation, previously shown to lead to a much greater increase (100-300%) in muscle insulin-mediated glucose uptake, did not change IRGT or HepG2GT mRNA in skeletal muscle or heart. Thus, both dietary manipulation and exercise training increase insulin-stimulated glucose uptake in skeletal muscle, but only exercise training increases IRGT mRNA. Therefore, exercise training apparently increases GT production, whereas dietary manipulation improves glucose transport in skeletal muscle by other mechanisms.
Diabetes 1991 Feb
PMID:Effects of exercise training and dietary manipulation on insulin-regulatable glucose-transporter mRNA in rat muscle. 199 74

Voltage-sensitive Ca2+ channels in cardiac left ventricular muscle membranes isolated from nondiabetic control and diabetic rats were measured with [3H]PN 200-110, a dihydropyridine derivative, as a ligand. The binding site (Bmax) of [3H]PN 200-110 in cardiac membranes isolated from streptozocin-induced diabetic (STZ-D) rats (128 +/- 10 fmol/mg protein) significantly (P less than 0.01) increased by 64% compared with that of control rats (78 +/- 4 fmol/mg protein) 10 wk after STZ administration without a significant change in Kd. However, the significant increase in Bmax of [3H]PN 200-110 binding in diabetic rats depended on the duration of diabetes such that the increase was not found until 6 wk after STZ injection. An 8-wk intensive insulin treatment, which was initiated 2 wk after STZ injection, normalized the increase in [3H]PN 200-110 binding in STZ-D rats to control levels (85 +/- 4 fmol/mg protein). Furthermore, [3H]PN 200-110 binding to control cardiac membranes was dose-dependently inhibited in the presence of verapamil, a phenylalkylamine Ca2+ antagonist, but that was not the case in cardiac membranes isolated from STZ-D rats. These results indicate that voltage-sensitive Ca2+ channels in cardiac muscle isolated from STZ-D rats are quantitatively and qualitatively altered, because the course of diabetes and the increase in the channels can be prevented by treatment with insulin.
Diabetes 1990 Sep
PMID:Increase in [3H]PN 200-110 binding to cardiac muscle membrane in streptozocin-induced diabetic rats. 214 87

There is evidence to suggest that increased nonenzymatic glycosylation (NEG) occurs in hyperglycemic states such as seen in diabetes mellitus. In order to examine the hypothesis that the development of cardiomyopathy in diabetes results from an increased nonenzymatic glycosylation of cardiac sarcolemmal proteins, rats were made diabetic by an intravenous (IV) injection of streptozotocin (65 mg/kg). Twelve weeks after the induction of diabetes, animal showed significantly lower heart rate, left ventricular systolic pressure, rate of contraction (+dp/dt), and rate of relaxation (-dp/dt), whereas left ventricular diastolic pressure was markedly increased. Furthermore, cardiac sarcolemmal Na+, K+ adenosine triphosphatase (ATPase) activity was significantly decreased in diabetic rats. When examined in cardiac crude membranes, as well as in purified sarcolemmal membranes prepared by two different procedures, the levels of NEG did not differ between control and diabetic animals; however, NEG levels were increased in kidney and skeletal muscle. These results indicate that chronic diabetes is associated with functional and biochemical alterations in cardiac muscle and suggest that NEG of cardiac sarcolemma may not play any role in the development of diabetic cardiomyopathy.
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PMID:Evidence against the involvement of nonenzymatic glycosylation in diabetic cardiomyopathy. 216 31

In normal conditions vascular permeability is precisely regulated by mechanisms which involve among others the macromolecules of extracellular matrix of the vascular wall. Permeability for a given substance will vary according to the anatomical localisation of the vessel determining also its structure and composition. In some pathological conditions, such as inflammation or diabetes, permeability can be abnormally increased. Increased permeability can be reproduced by i.v. collagenase injection. This permeability increase can be quantified by image analysis using appropriate tracers such as FITC-dextrans or horse-radish peroxidase, on histological sections from control and collagenase treated rats, pretreated or not with procyanidolic oligomers (PCO). We studied cerebral capillaries, aorta and cardiac muscle capillaries. It could be shown that previous treatment of animals with procyanidolic oligomers prevented the permeability increase produced by collagenase injection.
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PMID:[The effect of procyanidolic oligomers on vascular permeability. A study using quantitative morphology]. 216 37

Experimental diabetes was induced in wistar rats by intraperitoneal streptozotocin in a single dose of 60-65 mg per kg body weight. The changes of myocardium enzyme histochemistry and ultrastructure were observed during the 2nd, 4th, 6th, 12th week of diabetic state. The glucose metabolism enzyme activities such as ICDH, SDH, MDH, LDH, all decreased. The results indicated that glucose oxidation and glycolysis reduced. In the ventricular myocardium of diabetic rats, varying degrees of ultrastructural change were apparent. Swelling of mitochondria was observed. Focal areas showed myofibrillar degeneration, and cardiac muscle muscle cells showed condensation of nuclear chromatin. Lipid droplets could be seen in the cytoplasm of cardiac myocytes. The ultrastructural changes in the cardiac muscle cells were not accompanied by any changes in the endothelial cells and smooth muscle cells of the small vessels or capillaries. This study provides a strong evidence for the occurrence of a primary myocardial disease in the model of streptozotocin-induced diabetes. The primary cardiomyopathy was not dependent on vascular pathological changes.
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PMID:[Studies of enzyme histochemistry and ultrastructure of the myocardium in rats with streptozotocin-induced diabetes]. 252 54

Several of the adenosinetriphosphatase enzymes that are responsible for cardiac muscle contraction rely on high-energy phosphates supplied by the creatine kinase (CK) system. Experimental diabetes mellitus has been shown to cause a decrease in the maximal contractile performance of the heart. We postulated that the decrease in contractile performance may be explained in part by a decrease in CK enzyme activity. To evaluate this possibility, we determined the level of CK activity and isoenzyme distribution in ventricular homogenates from normal, diabetic, and insulin-treated diabetic rats. We found that total CK activity was decreased by 35% in diabetic hearts and that a 66% reduction in the cardiac-specific MB isoenzyme occurs. Using a cDNA probe for CK-muscle (M) RNA in Northern blot analysis, we determined that a 61.1% decrease in CK-M mRNA occurs in diabetes. Chronic insulin therapy for 1 mo restores CK-M mRNA levels and enzyme activity. In conclusion, diabetes-induced CK enzyme decreases are mediated in part by a lower level of CK-M mRNA that codes for the major CK-M subunit protein. Decreased performance of the CK system may contribute to diabetic cardiomyopathy.
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PMID:Diabetes decreases creatine kinase enzyme activity and mRNA level in the rat heart. 267 31

The metabolism of pantothenic acid (Pa) by cardiac muscle was studied in normal and diabetic rats. Tissue levels of Coenzyme A (CoA) are elevated in the heart during early (6 to 12 h) diabetes, remains at a high level for several days, and then returns to normal or below normal levels. The increase in total tissue CoA mainly occurs in myocytes as indicated by isolation of cardiac myocytes from control and diabetic animals and measuring their content of CoA. The CoA concentration increased from 37 to 93 microM in the cytosolic compartment and from 2.0 to 2.6 mM in the mitochondrial matrix. These effects of diabetes were reversed by insulin treatment. CoA synthesis in hearts removed from control rats and perfused in vitro was stimulated by including in the perfusate Pa, cysteine and dithiothreitol, but no exogenous energy substrate. This stimulated in vitro rate of CoA synthesis was reduced in hearts removed from diabetic animals, and the reduction increased with duration of diabetes. The reduced rate in diabetic hearts resulted from both a decreased rate of Pa phosphorylation and decreased Pa transport. Transport of Pa into myocytes was decreased by as much as 80% in hearts from diabetic animals. The low transport rate was due to a decrease in Vmax with no apparent change in Km. Treatment of the isolated heart with insulin did not correct the diabetic-induced reduction in Pa transport. The transport rate in normal and diabetic hearts was not influenced by the type of energy substrate provided to the heart.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Metabolism of pantothenic acid in hearts of diabetic rats. 279 60


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