Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “HEXOSES”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,639 records · Page 91Linked to original sources
PubMed2003

Changes in glutathione, glutathione-linked enzymes and hexose monophosphate shunt enzymes in senile cataract.

Changes in glucose-6-phosphate dehydrogenase (G-6-PD), glutathione reductase (GSH-R), reduced glutathione (GSH), glutathione peroxidase (GSH-PO), transketolase (TK) and transaldolase (TA) were studied in lens and red blood cells (RBCs) to understand the possible biochemical mechanisms responsible for the development of senile cataract. The activity of G-6-PD was increased in lens, though not so in erythrocytes during cataractogenesis. A marked decrease was observed in GSH level and GSH-R activity in the lens and RBCs of the cataractous group. The activity of GSH-PO was remarkably high in lens but not in the erythrocytes during the maturity of cataract. The activity of TK decreased gradually in both the lens and erythrocytes. The activity of TA decreased in erythrocytes but increased in the lens with maturation of cataract.

Adult↗
PubMed1975

Leucocyte energy metabolism. V. Glycolytic and hexose monophosphate shunt enzymes in leucocytes from adults and newborn infants.

The activities of ATP-consuming and ATP-producing steps of the Embden-Meyerhof pathway, as well as other glycolytic enzymes (phosphoglucomutase and enolase) and glucose-6-phosphate dehydrogenase are lower in leucocytes from cord blood than in white cells from adults. These results are related to previous observations (reduced anaerobic glycolysis and nitroblue tetrazolium-test in leucocytes from newborn infants) and discussed in connection with the fact that newborn infants are more susceptible to infections than normal adults.

Adult↗
PubMed1990

Insulin regulation of hexose transport in mouse 3T3-L1 cells expressing the human HepG2 glucose transporter.

Complementary DNA encoding a HepG2 cell-facilitated glucose transporter (GLUT1) was subcloned into a metal-inducible, mammalian expression vector, pLEN. Mouse 3T3-L1 fibroblasts transfected with this new construct, pLENGT, exhibited zinc-inducible expression of human glucose transporter mRNA, protein, and glucose transport activity, before and after differentiation into adipocytes. Both mouse host GLUT1 and expressed human GLUT1 proteins distributed about equally between 3T3-L1 adipocyte plasma membranes and low density microsomal membranes, while host skeletal muscle/adipocyte-type glucose transporter (GLUT4) was concentrated in the latter fraction. Mouse GLUT1 and GLUT4 proteins and the constitutively expressed human GLUT1 protein in pLENGT adipocytes were all redistributed from low density microsomal membrane to plasma membrane fractions in response to insulin. Insulin stimulated 2-deoxyglucose uptake in untransfected fibroblasts about 2-fold, while untransfected adipocytes displayed a 14-fold increase in deoxyglucose uptake in response to insulin. Both the expression of human GLUT1 protein and basal 2-deoxyglucose uptake by 75 microM zinc-treated pLENGT fibroblasts and adipocytes were increased approximately 3-fold over untransfected cells. In such pLENGT fibroblasts expressing human GLUT1 protein, however, the absolute values for insulin-stimulated increases in sugar uptake were no different than in control fibroblasts. As was observed in pLENGT fibroblasts, the increased basal sugar uptake by pLENGT adipocytes was additive with the insulin-stimulated increase in the rate of sugar uptake and, therefore, the -fold stimulation by insulin was markedly reduced. These data indicate that: 1) the membrane distributions of a glucose transporter protein, which is not responsive to insulin in HepG2 cells, and both mouse GLUT1 and GLUT4 glucose transporter isoforms are regulated by insulin in mouse 3T3-L1 adipocytes, and 2) the expressed human GLUT1 appears to contribute significantly to the rate of basal uptake but not to the insulin-stimulated increase in 2-deoxyglucose uptake by 3T3-L1 fibroblasts and adipocytes.

Adipose Tissue↗
PubMed1990

Interleukin 1 stimulates hexose transport in fibroblasts by increasing the expression of glucose transporters.

Exposure of quiescent cultures of human gingival fibroblasts (HuGi) and porcine synovicocytes (PSF) to human recombinant interleukin 1 alpha or -beta (IL1 alpha and -beta) enhanced the rate of glycolysis as judged by increased lactate production. The cytokines also increased uptake of [3H]2-deoxyglucose (DG) in a time- and dose-dependent manner. Stimulation of DG uptake was first evident 6-8 h following addition of IL1 and was maximal by 24-30 h. IL1 alpha and -beta were equipotent. Half-maximal stimulation occurred at approximately 1 pM IL1; maximal stimulation (2.5-4.5-fold in HuGi, 3-7-fold in PSF) was obtained with approximately 80 pM IL1. The dose-response curves for lactate production and DG uptake were similar. Increased DG uptake was blocked by specific antisera to IL1 and by inhibitors of protein and RNA synthesis but not by indomethacin, an inhibitor of prostaglandin production. DG uptake was enhanced by IL1 in serum-starved cells in the presence of neutralizing anti-platelet-derived growth factor serum. The effect was therefore not secondary to prostaglandin or platelet-derived growth factor production. No increase in cell cycling was detected in IL1-treated cells under the experimental conditions. Kinetic analysis revealed that the Vmax for DG uptake was increased by IL1 (from 36 to 144 pmol/min/mg of cell protein), whereas the Km was unchanged. HuGi cells were pulse-labeled with [35S]methionine following exposure to IL1. Cell lysates were immunoprecipitated using a specific antiserum raised against human erythrocyte glucose transporter. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis/autoradiography of these immunoprecipitates revealed dose- and time-dependent increases in the net rate of glucose transporter synthesis which mirrored the changes in DG uptake.

Animals↗
PubMedDate not supplied

The protective effect of glucose, but not 3-O-methyl glucose, against alloxan-induced diabetes depends upon the route of hexose administration.

It is well established that pretreatment with glucose prevents the development of alloxan-induced diabetes in rodents. This was confirmed in the present study, and a protective effect against the development of hyperglycemia, after alloxan administration (75 mg/kg body weight), in male NMRI mice was observed when glucose was injected i.v. 10 or 20 min before alloxan injection. However, when glucose was administered i.p., a protective effect was only observed when glucose was given 20 min before alloxan, despite the fact that the serum glucose concentrations at the time of the alloxan injection were similar in the i.v.- and i.p.-injected animals. Administration of 3-O-methyl glucose by i.v. and i.p. routes protected against the effects of alloxan to the same extent. When alloxan was administered at a lower dose (65 mg/kg body weight) both i.v. and i.p. administration of glucose 10 min before alloxan, protected against the development of hyperglycemia. It is concluded that the route of administration of glucose, but not of 3-O-methyl glucose, affects its protective action against alloxan-induced diabetes. The present findings suggest that an important feature of the glucose mediated protection against alloxan-induced diabetes is the metabolism of glucose within the B-cells, rather than via extracellular effects on the B-cell plasma membrane.

3-O-Methylglucose↗
PubMed1986

Effects of retinoic acid on growth, insulin secretion, and hexose incorporation into macromolecules of a continuously growing, insulin-secreting cell line (RINm5F).

The continuously growing, insulin-secreting cell line RINm5F does not respond to glucose with increased rates of insulin secretion and cell proliferation. The possibility that retinoic acid, which acts as a differentiating agent in several cell systems, could induce such responses to glucose has been investigated. Retinoic acid (10(-6)-10(-5) mol/l) failed to affect the cell viability, cell proliferation, 3H-thymidine incorporation or the DNA contents of the cultured RINm5F cells, irrespective of the glucose concentration of the culture medium. The insulin release was not affected either by glucose or by retinoic acid. Higher concentrations of the drug (10(-4) mol/l) proved toxic to the cells. The incorporation of 3H-mannose and 3H-glucosamine into TCA precipitable material of the RINm5F cells was strongly decreased by an increased glucose concentration of the medium. The incorporation of 3H-mannose, but not that of 3H-glucosamine, into macromolecules which could be precipitated with Concanavalin A or wheat germ lectin was diminished by retinoic acid (10(-5) mol/l).

Cell Division↗
PubMed1987

Adriamycin resistance in human tumor cells associated with marked alteration in the regulation of the hexose monophosphate shunt and its response to oxidant stress.

We found that Adriamycin increased the pentose phosphate shunt activity in both Adriamycin-sensitive (WT) and Adriamycin-resistant (ADRR) human breast cancer MCF-7 cells. In contrast, hydrogen peroxide and cumene hydroperoxide markedly stimulated pentose-shunt activity in ADRR but only moderately increased the activity in WT cells. Furthermore, the altered oxidation-reduction regulation is associated with changes intrinsic to the key enzymes of the pentose-shunt pathway, glucose-6-phosphate dehydrogenase, and 6-phosphogluconate dehydrogenase and with glutathione peroxidase. We found the Vmax values for glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase were 50- and 4-fold lower, respectively, in ADRR than WT cells and the Kms of NADP+ were 10-fold lower in ADRR than WT. The activity of glutathione reductase in ADRR is 42% of that in WT. In spite of these changes, the response of the cells to both hydrogen peroxide and organic peroxide is not limited by either the capacity of the pentose shunt or glutathione reductase, but is determined by the activity of glutathione peroxidase and a glutathione transferase which possess peroxidase activity. The kinetic properties of the glucose-6-phosphate dehydrogenase in ADRR may, however, seriously limit the activity of cytochrome P-450 reductase, a major enzyme of Adriamycin conversion to a free radical.

Benzene Derivatives↗