Induction of renal phosphoenolpyruvate carboxykinase mRNA: suppressive effect of glucose

1989 ◽  
Vol 257 (1) ◽  
pp. F145-F151
Author(s):  
A. S. Pollock
Keyword(s):  
Metabolic Acidosis ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Suppressive Effect ◽  
Oral Glucose ◽  
Prolonged Fasting ◽  
Glucose Loading ◽  
Glucose Administration ◽  
Liver And Kidney ◽  
Gluconeogenic Enzyme ◽  
Effect Of Glucose

The mRNA for the important gluconeogenic enzyme phosphoenolpyruvate carboxykinase (GTP) (PEPCK; EC 4.1.1.32) is expressed in liver and kidney. In the kidney, acidosis is a unique and potent stimulus, whereas insulin, the major counterregulatory hormone of gluconeogenesis, has no effect. In this study, we find that oral glucose administration to rats rapidly decreases the abundance of renal PEPCK mRNA by 50–72%. This reduction takes place in normal euglycemic, in insulin-induced hypoglycemic, and in streptozotocin-induced hyperglycemic diabetic animals. The effect of glucose is not seen in the presence of metabolic acidosis, whether induced by NH4Cl or by prolonged fasting. Therefore, it appears that oral glucose loading is a physiological suppressor of renal PEPCK message abundance, although not in acidosis.

Effect of glucose loading on concentrations of chromium in plasma and urine of healthy adults.

1988 ◽  
Vol 34 (6) ◽  
pp. 1114-1116 ◽  
Author(s):  
B W Morris ◽  
H Griffiths ◽  
G J Kemp
Keyword(s):  
Healthy Volunteers ◽  
Glucose Concentration ◽  
Small Study ◽  
Oral Glucose ◽  
Oral Glucose Load ◽  
Glucose Load ◽  
Glucose Loading ◽  
Glucose Administration ◽  
Effect Of Glucose ◽  
Apparently Healthy

Abstract We report here a small study designed to identify the effect of a 75-g oral glucose load on concentrations of chromium in plasma and urine of apparently healthy volunteers. We detected a consistent and significant (P less than 0.01) decline in plasma chromium after glucose administration, the nadir of the chromium response coinciding with the zenith of the glucose concentration.

Hepatic glycogen in humans. II. Gluconeogenetic formation after oral and intravenous glucose

1989 ◽  
Vol 257 (2) ◽  
pp. E158-E169 ◽  
Author(s):  
J. Radziuk
Keyword(s):  
Human Subjects ◽  
Glucose Production ◽  
Glucose Infusion ◽  
Constant Infusion ◽  
Hepatic Glycogen ◽  
Oral Glucose ◽  
Intravenous Glucose ◽  
Glucose Loading ◽  
Glucose Administration

The amount of glycogen that is formed by gluconeogenetic pathways during glucose loading was quantitated in human subjects. Oral glucose loading was compared with its intravenous administration. Overnight-fasted subjects received a constant infusion or [3-3H]glucose and a marker for gluconeogenesis, [U-14C]lactate or sodium [14C]bicarbonate [14C]bicarbonate). An unlabeled glucose load was then administered. Postabsorptively, or after glucose infusion was terminated, a third tracer ([6-3H]glucose) infusion was initiated along with a three-step glucagon infusion. Without correcting for background stimulation of [14C]glucose production or for dilution of 14C with citric acid cycle carbon in the oxaloacetate pool, the amount of glycogen mobilized by the glucagon infusion that was produced by gluconeogenesis during oral glucose loading was 2.9 +/- 0.7 g calculated from [U-14C]-lactate incorporation and 7.4 +/- 1.3 g calculated using [14C]bicarbonate as a gluconeogenetic marker. During intravenous glucose administration the latter measurement also yielded 7.2 +/- 1.1 g. When the two corrections above are applied, the respective quantities became 5.3 +/- 1.7 g for [U-14C]lactate as tracer and 14.7 +/- 4.3 and 13.9 +/- 3.6 g for oral and intravenous glucose with [14C]bicarbonate as tracer (P less than 0.05, vs. [14C]-lactate as tracer). When [2-14C]acetate was infused, the same amount of label was incorporated into mobilized glycogen regardless of which route of glucose administration was used. Comparison with previous data also suggests that 14CO2 is a potentially useful marker for the gluconeogenetic process in vivo.

Reciprocal changes in gluconeogenic enzyme activity in liver and kidney by VMH lesion

1983 ◽  
Vol 245 (1) ◽  
pp. E14-E18
Author(s):  
K. Nagai ◽  
S. Inoue ◽  
H. Nakagawa
Keyword(s):  
Nervous System ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Biological Clock ◽  
Ventromedial Hypothalamus ◽  
Daily Rhythms ◽  
Liver And Kidney ◽  
Gluconeogenic Enzyme ◽  
Sympathetic Nervous ◽  
Bilateral Lesions ◽  
Reciprocal Change

The effects of bilateral lesions of the ventromedial hypothalamus (VMH) on daily rhythms of the activity of a gluconeogenic enzyme, phosphoenolpyruvate carboxykinase (PEPCK), in the liver and kidney of rats were examined. PEPCK activity in the liver was considerably lowered by VMH lesions, but its rhythm remained similar to that of control liver. In contrast, PEPCK activity in the kidney was markedly elevated by the lesions. From these findings, it is suggested that the VMH is not the site of the master biological clock of the rhythm of PEPCK activity. Although these results do not exclude the possibility that hyperphagia and hyperinsulinemia associated with VMH lesions induce changes in the levels of PEPCK activities, they support the hypothesis that suppression of the sympathetic nervous system causes the changes in PEPCK activity through direct or indirect mechanisms. These findings also suggest that the reciprocal change in PEPCK activities in the liver and kidney after VMH lesions is related to complementary functions of the two organs in maintenance of homeostasis of blood glucose.

Suppressive effect of glucose administration on the binding of prolactin by rat liver

Metabolism ◽  
1990 ◽  
Vol 39 (6) ◽  
pp. 568-576 ◽  
Author(s):  
A.David Goodman ◽  
Susan Hoekstra ◽  
Joseph W. Monahan ◽  
Ellen H. Danis
Keyword(s):  
Rat Liver ◽  
Suppressive Effect ◽  
Glucose Administration ◽  
Effect Of Glucose

scholarly journals Pancreatic Insulinoma Presenting with Postprandial Hypoglicemias

2012 ◽  
Vol 19 (1) ◽  
pp. 99-103
Author(s):  
A. Florentiu ◽  
R. Barbu ◽  
M. Mitrache ◽  
R. Militaru ◽  
N. Georgescu ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Oral Glucose ◽  
Prolonged Fasting ◽  
Glucose Loading ◽  
Pancreatic Tail ◽  
Fasting Test ◽  
Pancreatic Insulinoma ◽  
Magnetic Resonance Scan ◽  
Fasting Hypoglycemia

Pancreatic Insulinoma Presenting with Postprandial HypoglicemiasWe report the case of an obese 58 years old patient evaluated for hypoglycemia. The response to a prolonged fasting test was normal, but symptomatic hypoglycemia ensued after mixed meals and with oral glucose loading. A magnetic resonance scan of the abdomen revealed a pancreatic tail tumor, histologically diagnosed as benign insulinoma after successful laparotomy. "Glucose-responsive" insulinomas, although rare, have been previously described in the literature. Therefore, the diagnosis of insulinoma should also be considered in patients that exhibit postprandial rather than fasting hypoglycemia.

scholarly journals High Carbohydrate Diet Increased Glucose Transporter Protein Levels in Jejunum but Did Not Lead to Enhanced Post-Exercise Skeletal Muscle Glycogen Recovery

Nutrients ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 2140
Author(s):  
Yumiko Takahashi ◽  
Yutaka Matsunaga ◽  
Hiroki Yoshida ◽  
Terunaga Shinya ◽  
Ryo Sakaguchi ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Glucose Transporter ◽  
High Carbohydrate Diet ◽  
Oral Glucose ◽  
Carbohydrate Diet ◽  
Post Exercise ◽  
Glucose Administration ◽  
Protein Levels ◽  
High Carbohydrate ◽  
Glucose Transporter 2

We examined the effect of dietary carbohydrate intake on post-exercise glycogen recovery. Male Institute of Cancer Research (ICR) mice were fed moderate-carbohydrate chow (MCHO, 50%cal from carbohydrate) or high-carbohydrate chow (HCHO, 70%cal from carbohydrate) for 10 days. They then ran on a treadmill at 25 m/min for 60 min and administered an oral glucose solution (1.5 mg/g body weight). Compared to the MCHO group, the HCHO group showed significantly higher sodium-D-glucose co-transporter 1 protein levels in the brush border membrane fraction (p = 0.003) and the glucose transporter 2 level in the mucosa of jejunum (p = 0.004). At 30 min after the post-exercise glucose administration, the skeletal muscle and liver glycogen levels were not significantly different between the two diet groups. The blood glucose concentration from the portal vein (which is the entry site of nutrients from the gastrointestinal tract) was not significantly different between the groups at 15 min after the post-exercise glucose administration. There was no difference in the total or phosphorylated states of proteins related to glucose uptake and glycogen synthesis in skeletal muscle. Although the high-carbohydrate diet significantly increased glucose transporters in the jejunum, this adaptation stimulated neither glycogen recovery nor glucose absorption after the ingestion of post-exercise glucose.

Enhanced plasma norepinephrine response to upright posture and oral glucose administration in elderly human subjects

Metabolism ◽  
1980 ◽  
Vol 29 (6) ◽  
pp. 532-539 ◽  
Author(s):  
James B. Young ◽  
John W. Rowe ◽  
Johanna A. Pallotta ◽  
David Sparrow ◽  
Lewis Landsberg
Keyword(s):  
Human Subjects ◽  
Plasma Norepinephrine ◽  
Oral Glucose ◽  
Upright Posture ◽  
Glucose Administration

scholarly journals Concentration-Dependent Antioxidant/Pro-Oxidant Activity of Ascorbic Acid in Chickens

2012 ◽  
Vol 66 (6) ◽  
pp. 256-260
Author(s):  
Nadežda Berzina ◽  
Jurijs Markovs ◽  
Mirdza Apsīte ◽  
Svetlana Vasiļjeva ◽  
Galina Smirnova ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Ascorbic Acid ◽  
Cadmium Concentration ◽  
Dehydroascorbic Acid ◽  
Cadmium Accumulation ◽  
Suppressive Effect ◽  
High Dose ◽  
Dependent Manner ◽  
Treatment Groups ◽  
Liver And Kidney

The effects of ascorbic acid supplementation on biomarkers of oxidative stress, cadmium accumulation in organs, immune system activity and kidney function in chickens were investigated. The treatment groups of chickens were fed either plain diet or diet supplemented with ascorbic acid at 100, 500, 1000 and 2000 mg/kg for four weeks. Liver and kidney tissues were assayed for cadmium concentration, and the hepatic levels of ascorbic acid and dehydroascorbic acid (DHAA; the oxidised form), malondialdehyde, glutathione, activity of glutathione peroxidase, blood serum uric acid, creatinine, lysozyme and circulating immune complexes were measured. Supplementation with a high dose of ascorbic acid (1000 and 2000 mg/kg in the diet) caused an imbalance between pro-oxidative and antioxidative activities, and induced a suppressive effect on innate immunity. The results suggest that oxidative stress compromises renal function. We observed that ascorbic acid increased cadmium accumulation in a dose-dependent manner.

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