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)

The phosphorylated form of liver glycogen phosphorylase (alpha-1,4-glucan : orthophosphate alpha-glucosyl-transferase, EC 2.4.1.1) (phosphorylase a) is active and easily measured while the dephosphorylated form (phosphorylase b), in contrast to the muscle enzyme, has been reported to be essentially inactive even in the presence of AMP. We have purified both forms of phosphorylase from rat liver and studied the characteristics of each. Phosphorylase b activity can be measured with our assay conditions. The phosphorylase b we obtained was stimulated by high concentrations of sulfate, and was a substrate for muscle phosphorylase kinase whereas phosphorylase a was inhibited by sulfate, and was a substrate for liver phosphorylase phosphatase. Substrate binding to phosphorylase b was poor (KM glycogen = 2.5 mM, glucose-1-P = 250 mM) compared to phosphorylase a (KM glycogen = 1.8 mM, KM glucose-1-P = 0.7 mM). Liver phosphorylase b was active in the absence of AMP. However, AMP lowered the KM for glucose-1-P to 80 mM for purified phosphorylase b and to 60 mM for the enzyme in crude extract (Ka = 0.5 mM). Using appropriate substrate, buffer and AMP concentrations, assay conditions have been developed which allow determination of phosphorylase a and 90% of the phosphorylase b activity in liver extracts. Interconversion of the two forms can be demonstrated in vivo (under acute stimulation) and in vitro with little change in total activity. A decrease in total phosphorylase activity has been observed after prolonged starvation and in diabetes.
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PMID:Characteristics of the dephosphorylated form of phosphorylase purified from rat liver and measurement of its activity in crude liver preparations. 0 75

The effects of intravenous administration of potassium phosphate in the treatment of diabetic ketoacidosis were studied in nine children, ages 9 9/12 to 17 10/12 yr. During phosphate infusion (20--40 meq/L of fluid), all children maintained normal serum concentrations of phosphorus. Transient hypocalcemia occurred in six and transient hypomagnesemia in five patients. One child developed carpopedal spasms refractory to intravenous infusion of calcium gluconate but responsive to intramuscular injection of magnesium sulfate. In three patients, serum levels of intact parathyroid hormone were low at the time of hypocalcemia, an observation that suggests transient hypoparathyroidism. This study indicates that the use of potassium phosphate as the sole source of potassium replacement might potentiate ketoacidosis-induced hypocalcemia through multiple mechanisms.
Diabetes Care
PMID:Hypocalcemia, hypomagnesemia, and transient hypoparathyroidism during therapy with potassium phosphate in diabetic ketoacidosis. 11 30

As estetrol (E4) is believed to be the steroid most likely to wholly dependent on fetal origin, we developed a radiommunoassay for unconjugated and conjugated E4 (E4-U and E4-G) and investigated plasma and urinary levels serially throughout the second half of pregnancy to establish their validity by means of monitoring or screening tests to assess fetal well-being. E4 exhibits a remarkable increase during the latter half of pregnancy. At term, the mean E4-U level in maternal peripheral plasma was 0.67 +/- 0.33 ng/ml, a five fold increase from that at 28 weeks; E4-G was 4.57 +/- 2.84 ng/ml, showing a four fold increase; and E4-G levels in maternal urine were 1.68 +/- 0.96 mg/day, showing a three fold increase from that at 28 weeks. E4-U and E4-G levels showed no diurnal change. The coefficient of the correlation between plasma E4-U and E4-G was 0.699, which is satisfactory, but no correlation was found between urinary and plasma E4 levels. A significant correlation was shown between maternal and umbilical E4-U (r=0.820) and E4-G (r=0.608). No relationships between E4 levels and birth weight were detected. Pre-eclampsia, Rh-isoimmunization and diabetes mellitus are common complications of pregnancy which may cause latent fetal distress. Prenatal fetal assessment was performed by serial daily evaluations of these E4 values. In pre-eclampsia resulting in a small full term baby, E4 levels were mostly below normal mean values or failed to show an increased pattern. In addition, the E4 levels decreased in one case of neonatal death. In Rh-isoimmunization, plasma E4-G levels were lower in the group affected severely by the hemolytic desease. In a patient with diabetes mellitus delivered of a healthy baby, E4 levels were within the range of a normal pregnancy. In order to evaluate fetal and placental reserve capacities as well as feto-placental function, the dehydroepiandrosterone sulfate (DHA-S) loading test was performed by loading selected subjects with 50 mg of DHA-S, then serially measuring the E4 in the maternal plasma and urine. Intravenous infusion of 50 mg of DHA-S was completed in 60 minutes. A rapid and sharp increase of plasma E4 was observed, reaching maximal concentrations at 120 minutes in normal pregnancies. However, urinary levels showed patterns similar to those reported for estriol (E3). In some abnormal pregnancies, no increased or delayed patterns were observed in plasma E4-G levels, while the serial levels remained within the normal range. This possibly suggests that in these pregnancies, fetal functions had been inhibited or had reached their limit. It is concluded that the simultaneous determinations of serial E4 levels accompanied by the DHA-S loading test may be of value in assessing fetal well-being and reserve capacity and may therefore improve fetal and neonatal prognosis in abnormal pregnancies.
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PMID:[The determination of plasma and urinary estetrol (E4) for assessing fetal and neonatal prognosis (author's transl)]. 14 80

The incorporation of [35S]sulfate into glycosaminoglycans was studied in cultures of normal and diabetic skin fibroblasts. Heparan sulfate was determined by column chromatography after enzymatic degradation of chondroitin sulfates and dermatan sulfate by chondroitinase ABE. Cultured skin fibroblasts from both insulin-dependent and noninsulin-dependent diabetics were found to have increased proportions of heparan sulfate in the media relative to the other sulfated glycosaminoglycans.
Diabetes 1979 Jan
PMID:Studies of cultured human fibroblasts in diabetes mellitus: changes in heparan sulfate. 15 51

Characterization of specificity of incorporation of 75Se-selenomethionine into human apoproteins following in-vivo injection of the radioactive amino acid precursor is reported. Apoprotein fractionation was attained by serial ultracentrifugation, anhydrous partial delipidization, decyl sulfate solubilization with Sephadex G-150 gel filtration into polypeptide fractions, Sf-I, and Sf-II, for VLDL, and LDL subfractions. Similarity of the Sf-I fractions isolated from VLDL, LDL1, and LDL2 was defined by gel exclusion volume, disk-gel electrophoresis, immunodiffusion, and amino acid composition. Enrichment of the Sf-I fractions with 75Se-SM in VLDL and LDL subfractions was observed, suggesting a possible use for this isotopic method for the investigation of apoprotein metabolism.
Diabetes 1976 Jan
PMID:Incorporation of 75Se-selenomethionine into human apoproteins. I. Characterization of specificity in very-low-density and low-density lipoproteins. 17 5

A number of cortizol metabolic indices were examined in 162 patients with moderately severe and severe diabetes mellitus of different duration. The following disturbances of the hormone metabolism which depended on decompensation of the disease were revealed: changes in the rate of cortizol elimination from the circulation, the prevalence of compounds with the oxygroup in the 11th carbon atom, an increase of the urinary excretion of nonconjugated 17-OCS with a relative reduction of excretion of glucoronide fraction and some increase of the sulfate fraction content. Possible causes of the detected disturbances and the informative character of the method of 17-OCS determination in the urine after Silber and Porter in patients with diabetes mellitus are discussed.
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PMID:[Cortisol metabolism in diabetes mellitus]. 67 23

In four groups of persons, 1/healthy individuals, 2/ patients with diabetes mellitus, 3/ patients with peripheral vascular disease, and 4/ patients with hyperthyroidism, the urinary excretion of free cortisol, cortisone, cortisol sulfate and cortisone sulfate was estimated. In groups 2 and 3 the excretion of all four substances was elevated. In hyperthyroidism a preponderance of free cortisone over cortisol was registered. The ratios of the followed substances suggest in patients with peripheral vascular disease a detoriation in the normal excretion of the followed corticoids, based on a preponderance of 11-OH-corticosteroids over their 11-oxo-derivatives. This observation could be implicated in the mild hyperglycemia or decreased glucose tolerance, that is often found in atherosclerotic disease.
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PMID:The excretion of free cortisol, cortisone, cortisol sulfate and cortisone sulfate in peripheral vascular disease, diabetes mellitus and hyperthyroidism. 74 72

Lipids have been investigated in the light microscope with Scarlet-Blue and for the fluorescentmicroscopy with rhodamine B and sulforhodamine B. Both of these reactions gave weak results. After using nilblue-sulfate for the detecting of acid and neutral lipids the presence of acid lipids could be shown in the walls of the vessels of normoglycemic men and animals. In the asymptomatical diabetes the tinction of elastic membranes was more intensive. Both acid and neutral lipids are present in a higher concentration in this stadium of diabetes mellitus as well as in the manifest diabetes of man.
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PMID:[Histotopochemical investigations on elastic membranes of blood vessels with special regard to diabetes mellitus. III. Lipids (author's transl)]. 81 68

A preparation of plasma membranes isolated from human omental lipocytes is composed of about 15 major polypeptide components including three major glycoproteins with an apparent molecular weight range from 100000 to 23 000, as determined by sodium dodecyl sulfate - polyacrylamide gel electrophoresis. Extraction of this membrane preparation with sodium iodide or 2,3-dimethylmaleic anhydride solubilized 50 and 70% of the membrane protein, respectively, resulting from the extensive extraction of protein from all but two of the major membrane polypeptide components. This removal of protein did not affect the membrane's stereospecific D-glucose-uptake activity but did reduce its total specific [125I]insulin-binding activity by 46-67%. The binding of [125I]insulin to its specific receptor on lipocyte plasma membranes was detected at physiologic concentrations of the hormone and could be competitively displaced by increasing concentrations of native insulin. The kinetic behaviour of this reaction was approximated by Scatchard analysis, and both the affinity and binding capacity of the plasma membrane for insulin were increased at lower temperatures. These results suggest that D-glucose transport in human adipose tissue is mediated by an intrinsic component of the hydrophobic structure of the lipocyte plasma membrane, and represent a partial purification of this component. In addition, these studies demonstrate and characterize the binding of insulin to the plasma membrane isolated from human lipocytes. A quantitative study of this binding reaction may provide further understanding of the mechanisms underlying the decreased insulin responsiveness characteristic of human diabetes.
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PMID:D-Glucose uptake and insulin binding by the human adipose cell plasma membrane as a function of its polypeptide composition. 84 81

Abnormalities in axonal transport of proteins are thought to play an important role in the pathogenesis of diabetic neuropathy. Gangliosides exert a positive action on numerous alterations in biochemistry and physiology of diabetic nerves. This study was undertaken to assess the effects of exogenous gangliosides on the axonal transport of structural proteins such as actin and tubulin in the sensory fibers of short-term (9-wk) and long-term (6-mo) diabetic rats. Adult Sprague-Dawley rats were made diabetic with a single injection of 70 mg/kg streptozocin i.p. Subgroups were injected daily with either highly purified ganglioside mixture (10 mg/kg i.p.) or saline for 1 mo, beginning either 2 or 17 wk after streptozocin injection. Age-matched rats were used as controls. Axonal transport was studied by the pulse-labeling technique. Three weeks after labeling, sciatic nerves were dissected out and processed for sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fluorography. In diabetic rats of both experimental designs, the transport rate of tubulin and actin was decreased by approximately 30% compared with control rats. Ganglioside treatment counteracted such alterations in both 9-wk and 6-mo diabetic rats. These data suggest a pharmacological effect that could be correlated with molecular interactions between integral membrane glycolipids and cytoskeletal elements.
Diabetes 1992 Jul
PMID:Experimental diabetic neuropathy. Effect of ganglioside treatment on axonal transport of cytoskeletal proteins. 137 37


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