scholarly journals Glucose metabolism in the rat small intestine: the effect of glucose analogues on hexokinase activity (Short Communication)

1973 ◽  
Vol 132 (1) ◽  
pp. 125-128 ◽  
Author(s):  
Gwyneth M. Jones ◽  
R. John Mayer
Keyword(s):  
Small Intestine ◽  
Glucose Metabolism ◽  
Short Communication ◽  
Subcellular Location ◽  
Rat Small Intestine ◽  
Hexokinase Activity ◽  
A Value ◽  
Glucose Analogues ◽  
Effect Of Glucose

The effect of intubation of starved rats with solutions of glucose, 3-O-methylglucose, mannose, 2-deoxyglucose and sorbitol on the subcellular location of hexokinase in the mucosa of the small intestine was studied. Glucose, 3-O-methylglucose and mannose caused the soluble hexokinase activity to rise to a value similar to that found in fed animals, whereas sorbitol and 2-deoxyglucose caused smaller increases.

scholarly journals Glucose metabolism in the mucosa of the small intestine. A study of hexokinase activity

1968 ◽  
Vol 109 (1) ◽  
pp. 35-42 ◽  
Author(s):  
L M Srivastava ◽  
P. Shakespeare ◽  
G. Hübscher
Keyword(s):  
Small Intestine ◽  
Lactate Dehydrogenase ◽  
Glucose Metabolism ◽  
Guinea Pig ◽  
Intestinal Mucosa ◽  
Brush Border ◽  
Deae Cellulose ◽  
Mitochondrial Fraction ◽  
Type Ii ◽  
Hexokinase Activity

1. The intracellular distribution of hexokinase activity was studied in the mucosa of rat and guinea-pig small intestine. In the rat 60% and in the guinea pig 45% of the hexokinase activity of homogenates were recovered in a total particulate fraction that contained only 5–17% of the homogenate activity of hexose phosphate isomerase, pyruvate kinase, lactate dehydrogenase and overall glycolysis (formation of lactate from glucose). 2. Fractionation of homogenates from guineapig small intestine showed that the particulate hexokinase activity was chiefly in the mitochondrial fraction with a small proportion in the nuclei plus brush-border fraction. 3. After chromatography of the particle-free supernatants on DEAE-cellulose, hexokinase types I and II were determined quantitatively. No evidence was obtained for the presence of hexokinase type III or glucokinase. In the preparations from guinea pigs, hexokinase types I and II amounted to 69% and 31% respectively of the eluted activity; the corresponding values for preparations from rats were 5·8% and 94·2%. 4. Total and specific hexokinase activities decreased significantly in homogenates and particle-free supernatants prepared from the intestinal mucosa of rats starved for 36hr. and increased again after re-feeding. The decrease in hexokinase activity in the particle-free supernatant from starved rats was chiefly due to a decrease in the type II enzyme.

scholarly journals The effect of glucose on the activity of phosphofructokinase in the mucosa of rat small intestine

1984 ◽  
Vol 218 (2) ◽  
pp. 459-464 ◽  
Author(s):  
A Jamal ◽  
G L Kellett ◽  
J P Robertson
Keyword(s):  
Small Intestine ◽  
Intestinal Mucosa ◽  
Small Intestinal Mucosa ◽  
Rat Small Intestine ◽  
Short Term ◽  
Small Intestinal ◽  
Rate Limiting ◽  
Effect Of Glucose ◽  
Acid Labile

In common with other phosphofructokinase isoenzymes, phosphofructokinase in the epithelial cells of rat small-intestinal mucosa is activated by fructose 2,6-bisphosphate. However, fructose 2,6-bisphosphate was found not to be present in mucosa as judged by three criteria: (1) chromatography on Sephadex G-25 of crude mucosal extracts from fed rats did not result in a decrease, or indeed any change, in the activity of phosphofructokinase under suboptimal conditions at pH7; (2) ultrafiltrates of mucosal extracts did not possess any acid-labile activating activity when tested against chromatographed liver phosphofructokinase; (3) phosphofructokinase-2 activity was not detectable in mucosal extracts. Furthermore, the perfusion in vitro of isolated loops of jejunum or the incubation of mucosal scrapings from either fed rats or rats starved for 48 h showed that the activity of mucosal phosphofructokinase is not subject to short-term regulation by glucose. These observations are consistent with the view that phosphofructokinase is the rate-limiting enzyme of glycolysis in intestinal mucosa and account for the fact that the rate of glucose utilization by rat small intestine is not very responsive to changes in the concentration of glucose in the lumen.

scholarly journals Glucose metabolism in the mucosa of the small intestine. The effect of glucose on hexokinase activity

1969 ◽  
Vol 111 (1) ◽  
pp. 63-67 ◽  
Author(s):  
P. Shakespeare ◽  
L M Srivastava ◽  
G. Hübscher
Keyword(s):  
Small Intestine ◽  
Similar Amount ◽  
Long Chain Fatty Acids ◽  
Stomach Tube ◽  
Hexokinase Activity ◽  
Dietary Components ◽  
Effect Of Glucose ◽  
Long Chain

1. The effect of three dietary components on hexokinase activity in the mucosa of rat small intestine was studied in vivo. Glucose, amino acids or an emulsion of monoglyceride with long-chain fatty acids were given by stomach tube to previously starved rats, and hexokinase activity was determined in the particle-free supernatant of mucosal homogenates. The formation of lactate from glucose and glucose 6-phosphate respectively was also measured. 2. When the three dietary components were given in isocaloric amounts, only glucose brought about an increase in hexokinase activity. 3. Intravenous injection of a similar amount of glucose to that given orally did not alter hexokinase activity. 4. An increase in the hexokinase activity of the particle-free supernatant prepared from mucosal homogenates was also observed after sacs of the small intestine of starved rats had been incubated in vitro in a medium containing glucose. Hexokinase activity increased to the values observed in corresponding preparations from fed rats, and this increase was strictly glucose-dependent.

scholarly journals The acute regulation of glucose absorption, transport and metabolism in rat small intestine by insulin in vivo

1984 ◽  
Vol 219 (3) ◽  
pp. 1027-1035 ◽  
Author(s):  
G L Kellett ◽  
A Jamal ◽  
J P Robertson ◽  
N Wollen
Keyword(s):  
Small Intestine ◽  
Glucose Metabolism ◽  
Lactate Production ◽  
Glucose Absorption ◽  
Serum Lactate ◽  
Rat Small Intestine ◽  
Anaesthetized Rats ◽  
Acute Changes

The effect of acute changes in insulin concentrations in vivo on the absorption, transport and metabolism of glucose by rat small intestine in vitro was investigated. Within 2 min of the injection of normal anaesthetized rats with anti-insulin serum, lactate production and glucose metabolism were respectively diminished to 28% and 21% of normal and the conversion of glucose into lactate became quantitative. These changes correlated with the inhibition of two mucosal enzymes, namely the insulin-sensitive enzyme pyruvate dehydrogenase, and phosphofructokinase, which was shown by cross-over measurements to be the rate-limiting enzyme of glycolysis in mucosa. The proportion of glucose translocated unchanged from the luminal perfusate to the serosal medium was simultaneously increased from 45% to 80%. All the changes produced by insulin deficiency were completely reversed with 2 min when antiserum was neutralized by injection of insulin in vivo. The absorption and transport of 3-O-methylglucose were unaffected by insulin. It is concluded that glucose metabolism in rat small intestine is subject to short-term regulation by insulin in vivo and that glucose absorption and transport are regulated indirectly in response to changes in metabolism. Moreover, transport and metabolism compensate in such a way as to deliver the maximal ‘effective’ amount of glucose to the blood, whether as glucose itself or as lactate for hepatic gluconeogenesis.

Effects of insulin, glucose analogues, and pyruvate on vascular responses to anoxia in isolated ferret lungs

1993 ◽  
Vol 74 (5) ◽  
pp. 2426-2431 ◽  
Author(s):  
C. M. Wiener ◽  
J. T. Sylvester
Keyword(s):  
Glucose Metabolism ◽  
Glucose Transport ◽  
Glucose Concentration ◽  
Constant Flow ◽  
Vascular Response ◽  
Pulmonary Vasodilation ◽  
The Third ◽  
Glucose Analogues ◽  
Series Of Experiments ◽  
Effect Of Glucose

In isolated ferret lungs, the vasopressor response to anoxia is characterized by an intense initial vasoconstriction, followed by marked vasodilation. This hypoxic pulmonary vasodilation (HPVD) is inhibited by perfusate glucose concentration > or = 15 mM. To determine whether this inhibition of HPVD was mediated by an effect of glucose transport or a product of glucose metabolism beyond pyruvate, we studied the effects of 5 mM glucose + insulin, transportable but nonmetabolizable analogues of glucose, and pyruvate on the pulmonary vascular response to anoxia. Isolated ferret lungs were ventilated with 28% O2 at constant flow. Perfusate glucose concentration was allowed to fall spontaneously. Thirty-minute anoxic exposures were performed at 60, 120, and 180 min of perfusion. Before the third anoxic exposure 15 mM glucose, 15 mM sucrose, 5 mM glucose (with 10 mM sucrose) + 10 mU/ml insulin, 15 mM 3-O-methylglucose (3-O-MG), or 15 mM alpha-methylglucose (alpha-MG) was added to the perfusate and vasomotor responses recorded. In another series of experiments, 15 mM pyruvate was added to the preparation at the beginning of perfusion. Peak vasoconstrictor responses were not different among groups. HPVD was greater in sucrose, insulin, 3-O-MG, alpha-MG, and pyruvate lungs than in high glucose lungs. These results suggest that glucose transport or a product of glucose metabolism beyond pyruvate was not responsible for inhibiting HPVD. We speculate that hyperglycemia inhibits HPVD by increasing production of ATP from the glycolytic pathway and that this ATP inhibits ATP-dependent K+ channels.

In situ demonstration of migration of dendritic cells released from rat small intestine to mesenteric lymph nodes

2001 ◽  
Vol 120 (5) ◽  
pp. A183-A183
Author(s):  
H KOBAYASHI ◽  
H NAGATA ◽  
S MIURA ◽  
T AZUMA ◽  
H SUZUKI ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Small Intestine ◽  
Lymph Nodes ◽  
Rat Small Intestine ◽  
Mesenteric Lymph Nodes ◽  
Mesenteric Lymph

Anti-inflammatory effect of STW 5, STW 6 and isolated extracts on the rat small intestine

2008 ◽  
Vol 29 (S 1) ◽  
Author(s):  
K Nieber ◽  
S Michael ◽  
K Grötzinger ◽  
JW Rauwald ◽  
O Kelber
Keyword(s):  
Small Intestine ◽  
Rat Small Intestine ◽  
Anti Inflammatory ◽  
Inflammatory Effect

Oral vanadate reduces Na(+)-dependent glucose transport in rat small intestine

Diabetes ◽  
1993 ◽  
Vol 42 (8) ◽  
pp. 1126-1132 ◽  
Author(s):  
K. L. Madsen ◽  
V. M. Porter ◽  
R. N. Fedorak
Keyword(s):  
Small Intestine ◽  
Glucose Transport ◽  
Rat Small Intestine
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