Fetal and neonatal metabolism in the pup of a canine diabetic mother. Fasting circulating fuels and neonatal glucose turnover

We have reported previously that a high glycolytic capacity develops soon after birth in enterocytes isolated from suckling newborn pigs. In the present work, we investigated whether such metabolic changes could affect intestinal glucose utilization in vivo and examined possible variations in glucose metabolism along the small intestine. Glucose utilization by individual tissues was assessed using the 2-deoxyglucose technique. The overall glucose utilization rate was doubled in suckling vs. fasting 2-day-old pigs because of significantly higher rates in all tissues studied, except for the brain. In parallel, enterocytes were isolated from the proximal, medium, or distal jejunoileum of newborn vs. 2-day-old pigs and assessed for their capacity to utilize, transport, and phosphorylate glucose. Intestinal glucose consumption accounted for approximately 15% of glucose turnover rate in suckling vs. 8% in fasting pigs. Moreover, there was a proximal-to-distal gradient of glucose utilization in the intestinal mucosa of suckling pigs. Such a gradient was also evidenced on isolated enterocytes. The stimulation of both hexokinase activity (HK2 isoform) and basolateral glucose transporter (GLUT2), as observed in the proximal jejunum, could account for such a site-specific effect of suckling.

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Distinct Changes in Gut Microbiota Are Associated with Estradiol-Mediated Protection from Diet-Induced Obesity in Female Mice

Metabolites ◽

10.3390/metabo11080499 ◽

2021 ◽

Vol 11 (8) ◽

pp. 499

Author(s):

Kalpana D. Acharya ◽

Hye L. Noh ◽

Madeline E. Graham ◽

Sujin Suk ◽

Randall H. Friedline ◽

...

Keyword(s):

Gut Microbiota ◽

Energy Homeostasis ◽

Whole Body ◽

Glucose Turnover ◽

Female Mice ◽

Adult Mice ◽

Diet Induced Obesity ◽

Metabolic Dysregulation ◽

Regulation Of Metabolism ◽

Junction Protein

A decrease in ovarian estrogens in postmenopausal women increases the risk of weight gain, cardiovascular disease, type 2 diabetes, and chronic inflammation. While it is known that gut microbiota regulates energy homeostasis, it is unclear if gut microbiota is associated with estradiol regulation of metabolism. In this study, we tested if estradiol-mediated protection from high-fat diet (HFD)-induced obesity and metabolic changes are associated with longitudinal alterations in gut microbiota in female mice. Ovariectomized adult mice with vehicle or estradiol (E2) implants were fed chow for two weeks and HFD for four weeks. As reported previously, E2 increased energy expenditure, physical activity, insulin sensitivity, and whole-body glucose turnover. Interestingly, E2 decreased the tight junction protein occludin, suggesting E2 affects gut epithelial integrity. Moreover, E2 increased Akkermansia and decreased Erysipleotrichaceae and Streptococcaceae. Furthermore, Coprobacillus and Lactococcus were positively correlated, while Akkermansia was negatively correlated, with body weight and fat mass. These results suggest that changes in gut epithelial barrier and specific gut microbiota contribute to E2-mediated protection against diet-induced obesity and metabolic dysregulation. These findings provide support for the gut microbiota as a therapeutic target for treating estrogen-dependent metabolic disorders in women.

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Effect of burn trauma on glucose turnover, oxidation, and recycling in guinea pigs.

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1977.233.2.e80 ◽

1977 ◽

Vol 233 (2) ◽

pp. E80

Author(s):

R R Wolfe ◽

J F Burke

Keyword(s):

Clearance Rate ◽

Guinea Pigs ◽

Glucose Oxidation ◽

Burn Injury ◽

Constant Infusion ◽

Glucose Turnover ◽

Glucose Kinetics ◽

Burn Trauma ◽

Glucose Clearance ◽

Low Rate

The simultaneous primed-constant infusion of [6-3H]- and [U-14C]glucose was used to determine the effect of burn injury on glucose turnover, oxidation, and recycling in guinea pigs. Eleven burned animals survived more than 72 h (survivors), whereas five died between 60 and 72 h postburn. All of the controls (n = 9) survived more than 72 h. At 48 h postburn, glucose turnover in the burned survivors was elevated 40% above that in control animals. A greater portion of the burned survivors' turnover was due to recycling and less was directed towards oxidation. The nonsurvivors had both a significantly depressed rate of appearance of glucose and an increased glucose clearance rate. Consequently, they were profoundly hypoglycemic and had a low rate of glucose oxidation. The alterations in glucose kinetics and oxidation apparent after burn did not reflect an inability of burned animals to oxidize exogenously infused glucose, however, because of 2-h infusion of 55 mumol/kg-min of unlabeled glucose doubled glucose oxidation in the burned survivors and tripled it in the nonsurvivors.

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Leg and arm lactate and substrate kinetics during exercise

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00273.2002 ◽

2003 ◽

Vol 284 (1) ◽

pp. E193-E205 ◽

Cited By ~ 107

Author(s):

G. van Hall ◽

M. Jensen-Urstad ◽

H. Rosdahl ◽

H.-C. Holmberg ◽

B. Saltin ◽

...

Keyword(s):

Skeletal Muscle ◽

Glucose Uptake ◽

Muscle Mass ◽

Lactate Concentration ◽

Whole Body ◽

Glucose Turnover ◽

Lactate Oxidation ◽

Arterial Lactate ◽

Lactate Uptake ◽

High Lactate

To study the role of muscle mass and muscle activity on lactate and energy kinetics during exercise, whole body and limb lactate, glucose, and fatty acid fluxes were determined in six elite cross-country skiers during roller-skiing for 40 min with the diagonal stride (Continuous Arm + Leg) followed by 10 min of double poling and diagonal stride at 72–76% maximal O2 uptake. A high lactate appearance rate (Ra, 184 ± 17 μmol · kg−1 · min−1) but a low arterial lactate concentration (∼2.5 mmol/l) were observed during Continuous Arm + Leg despite a substantial net lactate release by the arm of ∼2.1 mmol/min, which was balanced by a similar net lactate uptake by the leg. Whole body and limb lactate oxidation during Continuous Arm + Leg was ∼45% at rest and ∼95% of disappearance rate and limb lactate uptake, respectively. Limb lactate kinetics changed multiple times when exercise mode was changed. Whole body glucose and glycerol turnover was unchanged during the different skiing modes; however, limb net glucose uptake changed severalfold. In conclusion, the arterial lactate concentration can be maintained at a relatively low level despite high lactate Ra during exercise with a large muscle mass because of the large capacity of active skeletal muscle to take up lactate, which is tightly correlated with lactate delivery. The limb lactate uptake during exercise is oxidized at rates far above resting oxygen consumption, implying that lactate uptake and subsequent oxidation are also dependent on an elevated metabolic rate. The relative contribution of whole body and limb lactate oxidation is between 20 and 30% of total carbohydrate oxidation at rest and during exercise under the various conditions. Skeletal muscle can change its limb net glucose uptake severalfold within minutes, causing a redistribution of the available glucose because whole body glucose turnover was unchanged.

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