scholarly journals Glycogen Synthesis from Uridine Diphosphate Glucose in Brain

1960 ◽  
Vol 235 (11) ◽  
pp. 3054-3057
Author(s):  
Bruce M. Breckenridge ◽  
Elizabeth J. Crawford
Keyword(s):  
Glycogen Synthesis ◽  
Uridine Diphosphate ◽  
Uridine Diphosphate Glucose ◽  
Diphosphate Glucose

scholarly journals Studies on glycogen synthesis in pigeon liver homogenates. Glycogen synthesis from glucose monophosphates and uridine diphosphate glucose

1967 ◽  
Vol 105 (2) ◽  
pp. 515-519 ◽  
Author(s):  
V. N. Nigam
Keyword(s):  
Time Course ◽  
Initial Rate ◽  
Glycogen Synthesis ◽  
Uridine Diphosphate ◽  
Cytoplasmic Fraction ◽  
Uridine Diphosphate Glucose ◽  
Diphosphate Glucose ◽  
Liver Homogenates ◽  
Pigeon Liver ◽  
Glycogen Formation

Comparative time-course studies of glycogen synthesis from glucose 6-phosphate, glucose 1-phosphate and UDP-glucose show that glucose 1-phosphate forms glycogen at an initial rate faster than that obtained with glucose 6-phosphate and UDP-glucose. After 5min. the rates from glucose monophosphates are considerably slower. 2,4-Dinitrophenol decreases glycogen synthesis from both glucose monophosphates, whereas arsenate and EDTA increase glycogen synthesis from glucose 1-phosphate and inhibit the reaction from glucose 6-phosphate, galactose and galactose 1-phosphate. Mitochondria-free pigeon liver cytoplasmic fraction forms less glycogen from glucose monophosphates than does the whole homogenate. 2-Deoxyglucose 6-phosphate inhibits glycogen synthesis from glucose monophosphates. Glycogen formation from UDP-glucose is relatively unaffected by dinitrophenol, by arsenate, by EDTA, by 2-deoxyglucose 6-phosphate and by the removal of mitochondria from the whole homogenate.

HISTOCHEMICAL INVESTIGATION OF THE EFFECTS OF OESTROGEN, PROGESTERONE AND RELAXIN ON GLYCOGEN, AMYLOPHOSPHORYLASE, TRANSGLYCOSYLASE AND URIDINE DIPHOSPHATE GLUCOSE-GLYCOGEN TRANSFERASE IN UTERI OF MICE

1965 ◽  
Vol 32 (2) ◽  
pp. 245-257 ◽  
Author(s):  
KATHLEEN HALL
Keyword(s):  
Enzyme Activities ◽  
Glycogen Synthesis ◽  
Glandular Epithelium ◽  
Uridine Diphosphate ◽  
Phosphorylase Activity ◽  
Uridine Diphosphate Glucose ◽  
Ovariectomized Mice ◽  
Diphosphate Glucose ◽  
Arterial Muscle

SUMMARY (1) The effects of combinations of oestrogen, progesterone and relaxin on glycogen content, and on amylophosphorylase, transglycosylase and uridine diphosphate glucose-glycogen glucosyl transferase activities in the corpus uteri of intact and ovariectomized virgin mice were investigated by histochemical techniques. (2) Glycogen and the enzyme activities were localized to myometrial and arterial muscle fibres, mobilized leucocytes when present, and luminal and glandular epithelium. Transglycosylase activity was not found in glandular epithelium and no information was obtained about UDPG-glycogen synthesis in epithelium or in leucocytes; otherwise the distribution of the three activities appeared to be similar. (3) In untreated ovariectomized mice no glycogen was detected in vivo and phosphorylase activity was low. In untreated intact mice little histochemically detectable glycogen was found in myometrial muscle at any stage of the cycle and almost no UDPG-synthesized glycogen; amylophosphorylase activity appeared to be increased during pro-oestrus and oestrus. (4) Oestrogen produced increased amounts of glycogen in vivo and stimulated phosphorylase activity in both muscle layers in intact and ovariectomized mice; UDPG-glycogen synthesis was probably also increased. (5) Relaxin had no detectable effect on myometrial glycogen or on phosphorylase activity in non-primed ovariectomized mice, but both were increased when relaxin was given to oestrogen-primed ovariectomized mice or to intact mice at pro-oestrus or oestrus. Only small increases were detected in UDPG-glycogen synthesis. (6) In both intact and ovariectomized oestrogen-primed mice progesterone had a differential action on the two layers of the myometrium: it increased both glycogenolysis and phosphorylase activity in the longitudinal fibres, but inhibited phosphorylase activity in the circular fibres without resulting in glycogen synthesis in vivo. Results on UDPG-glycogen synthesis were inconclusive. Simultaneous administration of relaxin prevented the inhibitory action of progesterone on glycogen and phosphorylase activity in the circular muscle layer and UDPG-glycogen synthesis was also high in these mice. (7) No consistent effects of the hormones were detected on glycogen or enzyme activities in arterial muscle. (8) The histochemical tests visualized total phosphorylase activity but gave no information about hormonal influence on phosphorylase a and b ratios.

scholarly journals The activity of uridine diphosphate glucose–d-fructose 6-phosphate 2-glucosyltransferase in leaves

1967 ◽  
Vol 105 (3) ◽  
pp. 943-946 ◽  
Author(s):  
J. S. Hawker
Keyword(s):  
Sugar Cane ◽  
Sucrose Synthesis ◽  
Uridine Diphosphate ◽  
Leaf Extracts ◽  
Uridine Diphosphate Glucose ◽  
Rate Of Photosynthesis ◽  
Diphosphate Glucose ◽  
Sucrose Phosphate Synthetase ◽  
High Sucrose ◽  
Sucrose Phosphate

1. By using EDTA in reaction mixtures it was possible to determine the activity of sucrose phosphate synthetase in freshly prepared leaf extracts without the complications caused by sucrose phosphatase. 2. EDTA was found also to increase the activity of sucrose phosphate synthetase by as much as 100%. 3. High sucrose phosphate synthetase activities were found in leaf preparations in which sucrose phosphatase was inhibited by EDTA. By contrast with previous reports, the activities were sufficient to allow sucrose synthesis in leaves during photosynthesis to occur via sucrose phosphate. 4. Sugar-cane plants having different rates of photosynthesis also had different activities of sucrose phosphate synthetase in their leaves. 5. It is suggested that the activity of sucrose phosphate synthetase in leaves may play a role in the control of the rate of photosynthesis.

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