Glucose metabolism in thyroidectomized and normal dogs during rest and acute cold exposure

1975 ◽  
Vol 38 (2) ◽  
pp. 236-240 ◽  
Author(s):  
P. Paul ◽  
M. Donohue ◽  
W. L. Holmes
Keyword(s):  
Energy Expenditure ◽  
Glucose Level ◽  
Cold Exposure ◽  
Plasma Glucose ◽  
Turnover Rate ◽  
Control Period ◽  
Glucose Turnover ◽  
Glucose Levels ◽  
Acute Cold Exposure ◽  
Lower Glucose

Uniformly labeled (14C)glucose was infused iv at a constant rate into unanesthetized surgically thyroidectomized (THY) and normal dogs during the basal state at 22 degrees C and during cold exposure at 4–5 degrees C. 02 uptake, CO2 output, and plasma glucose levels were determined; from these rates of glucose turnover and oxidation were calculated. Comparison of THY with normal dogs shows that at a mean plasma glucose level of 103 mg/100 ml, a significantly lower glucose turnover rate was observed in THY dogs on the basis of a kg body weight, body surface area (m-2), but not per cal BMR. The same percentage of glucose turnover was immediately oxidized in THY and normal dogs, accounting for 16 and 15% of the total caloric expenditure, respectively. Acute cold exposure increased energy expenditure in both THY and normal dogs without a change in glucose level or turnover rate. However, the percentage of glucose turnover which was immediately oxidized as well as the amount of glucose oxidized increased significantly and proportionally to the increase in energy expenditure so that the percent of calories derived from plasma glucose oxidation remained the same as that observed during the control period.

Effect of cold exposure on plasma glucose and acetate turnover rates in sheep

2014 ◽  
Vol 54 (10) ◽  
pp. 1728 ◽  
Author(s):  
M. Al-Mamun ◽  
Y. Sako ◽  
H. Sano
Keyword(s):  
Plasma Concentration ◽  
Cold Exposure ◽  
Plasma Glucose ◽  
Turnover Rate ◽  
Isotopic Dilution ◽  
Glucose Turnover ◽  
Acetate Metabolism ◽  
Turnover Rates ◽  
Water Access ◽  
Esterified Fatty Acids

Isotopic dilution methodology of [U-13C]glucose and [1-13C]Na-acetate were performed simultaneously as primed continuous infusions to determine plasma glucose and acetate metabolism in sheep during thermoneutral (TN) and cold exposure (CE, 2−4°C). The experiment was performed using crossbred (Corriedale × Suffolk) sheep (n = 5; 3 male and 2 female; ~2 years old, 38 ± 2.5 kg of initial bodyweight). The animals were offered mixed hay of orchardgrass and reed canarygrass (40 : 60) 62 g/kg0.75/day with ad libitum water access. Concentration of plasma glucose was determined enzymatically using the glucose oxidase method. Plasma concentration of non-esterified fatty acids (NEFA) and glucose were higher (P = 0.01 and P = 0.05 respectively) during CE than TN. Plasma concentration and the turnover rate of acetate were numerically higher (P = 0.09 and P = 0.25 respectively) during CE than during TN. Plasma glucose turnover rate was higher (P = 0.02) during CE than TN. The present findings suggested that plasma acetate turnover rate tended to be elevated during CE, with further more extensive studies required to clarify the significance.

scholarly journals Ingestion of Helianthus tuberosus at Breakfast Rather Than at Dinner is More Effective for Suppressing Glucose Levels and Improving the Intestinal Microbiota in Older Adults

Nutrients ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 3035
Author(s):  
Hyeon-Ki Kim ◽  
Hanako Chijiki ◽  
Takuya Nanba ◽  
Mamiho Ozaki ◽  
Hiroyuki Sasaki ◽  
...  
Keyword(s):  
Older Adults ◽  
Glucose Level ◽  
Intestinal Microbiota ◽  
Control Period ◽  
Rate Of Change ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Helianthus Tuberosus ◽  
Glucose Levels ◽  
Nutritional Studies

To date, nutritional studies have focused on the total intake of dietary fiber rather than intake timing. In this study, we examined the effect of the timing of daily Helianthus tuberosus ingestion on postprandial and 24 h glucose levels, as well as on intestinal microbiota in older adults. In total, 37 healthy older adults (age = 74.9 ± 0.8 years) were recruited. The participants were randomly assigned to either a morning group (MG, n = 18) or an evening group (EG, n = 17). The MG and EG groups were instructed to take Helianthus tuberosus powder (5 g/day) just before breakfast or dinner, respectively, for 1 week after the 1-week control period. The glucose levels of all participants were monitored using a continuous glucose monitoring system throughout the 2 weeks. The intestinal microbiota was analyzed by sequencing 16S rRNA genes from feces before and after the intervention. There were no significant differences in the physical characteristics or energy intake between groups. Helianthus tuberosus intake led to decreases in tissue glucose levels throughout the day in both groups (p < 0.01, respectively). As a result of examining the fluctuations in tissue glucose levels up to 4 hours after each meal, significant decreases in the areas under the curves (AUCs) were observed for all three meals after intervention, but only in the MG (breakfast: p = 0.012, lunch: p = 0.002, dinner: p = 0.005). On the other hand, in the EG, there was a strong decrease in the AUC after dinner, but only slight decreases after breakfast and lunch (breakfast: p = 0.017, lunch: p = 0.427, dinner: p = 0.002). Moreover, the rate of change in the peak tissue glucose level at breakfast was significantly decreased in the MG compared to the EG (p = 0.027). A greater decrease was observed in the change in the blood glucose level after the ingestion of Helianthus tuberosus in the MG than in the EG. Furthermore, the relative abundance of Ruminococcus in the MG at the genus level was significantly higher at baseline than in the EG (p = 0.016) and it was also significantly lower after the intervention (p = 0.013). Our findings indicate that Helianthus tuberosus intake in the morning might have relatively stronger effects on the intestinal microbiota and suppress postprandial glucose levels to a greater extent than when taken in the evening.

Cold exposure of Southdown and Welsh Mountain sheep. 4. Changes in concentrations of free fatty acids, glucose, acetone, protein-bound iodine, protein and antibody in the blood

1969 ◽  
Vol 11 (4) ◽  
pp. 479-491 ◽  
Author(s):  
R. Halliday ◽  
A. R. Sykes ◽  
J. Slee ◽  
A. C. Field ◽  
A. J. F. Russel
Keyword(s):  
Serum Protein ◽  
Cold Exposure ◽  
Temperature Treatment ◽  
Acute Exposure ◽  
Protein Levels ◽  
Glucose Levels ◽  
Acute Cold Exposure ◽  
Effects Of Temperature ◽  
Antibody Levels ◽  
Female Sheep

SUMMARYTwenty-four Southdown and 24 Welsh Mountain year-old female sheep, half on high-plane and half on low-plane nutrition, were shorn and given two acute cold exposures in climate chambers. For 2 weeks before and 2 weeks between exposures the sheep were kept in a subcritical (+ 8°C) or a thermoneutral (+30°C) environment. Before the temperature treatment each sheep received an injection of Brucella abortus vaccine. Blood samples were taken during exposure to + 8°C and + 30°C and during the acute cold exposures for estimation of free fatty acid (FFA), protein-bound iodine (PBI), glucose, acetone, serum protein and antibody levels. FFA and glucose levels alone were measured in 32 similarly treated Scottish Blackface sheep.1. Low plane sheep had higher PBI levels at all temperatures, and higher glucose levels during acute cold exposure than high plane sheep. Otherwise most major effects were attributable to ambient temperature.2. At +8°C the PBI, FFA, glucose, serum protein and acetone levels were higher than at + 30°C.3. Blackface sheep had lower FFA and glucose levels than Southdown and Welsh sheep at both temperatures.4. During acute cold exposure, PBI, acetone and FFA levels increased further. PBI levels were highest in sheep previously at + 30°C, and acetone highest in sheep previously at + 8°C. Very high FFA levels were recorded, especially in sheep not previously cold-acclimatized.5. Glucose levels increased initially, but fell towards the end of acute exposure, suggesting that relatively less carbohydrate and more fat was utilized for energy metabolism during this period.6. Serum protein levels fell during acute exposure, possibly because protein catabolism increased. The proportions of albumin and γ-globulin increased and decreased respectively.7. No effects of temperature on antibody levels were detected.

The effects of methylprednisolone and diabetes on the turnover of alanine and on the transfer of carbon atoms from alanine to pyruvate and glucose in dogs

1980 ◽  
Vol 58 (7) ◽  
pp. 787-796 ◽  
Author(s):  
G. Hetenyi Jr. ◽  
B. Pagurek ◽  
Elizabeth A. Dittmar ◽  
Catherine Ferrarotto
Keyword(s):  
Plasma Level ◽  
Plasma Glucose ◽  
Turnover Rate ◽  
Glucose Turnover ◽  
Direct Proportion ◽  
Carbon Transfer ◽  
Tracer Methods ◽  
Pancreatectomized Dogs

The turnover rate of glucose, the irreversible disposal rate of alanine, and the transfer of carbon atoms from alanine to glucose were studied with the help of tracer methods in normal, methylprednisolone (MP) treated and pancreatectomized dogs. The incorporation of carbon from alanine into pyruvate was also followed. In comparison with normal dogs, in MP-treated dogs the plasma level of alanine and pyruvate were elevated by a factor of about 3 whereas the level of plasma glucose was increased by 10%. Both the turnover rate of glucose and the irreversible disposal rate of alanine were significantly higher. In pancreatectomized dogs plasma alanine and pyruvate levels were not different from normal. There was no increase in the irreversible disposal rate of alanine. Glucose turnover was about twice as much as in normals. The transfer of C atoms from alanine to glucose was increased in both MP-treated and pancreatectomized dogs. The increase was in direct proportion to the increase in the irreversible disposal rate of alanine in MP-treated dogs whereas in pancreatectomized dogs it was due to an increased fraction of the irreversible disposal rate of alanine being converted to circulating glucose. Thus two different mechanisms are responsible for the increased carbon transfer and hence presumably gluconeogenesis in MP-treated and in pancreatectomized animals. The role of insulin as the determinant of the preferred route to increase gluconeogenesis is discussed.

scholarly journals Cold-induced hyperphagia requires AgRP-neuron activation in mice

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Jennifer Deem ◽  
Chelsea L Faber ◽  
Christian Pedersen ◽  
Bao Anh Phan ◽  
Sarah A Larsen ◽  
...  
Keyword(s):  
Food Intake ◽  
Energy Expenditure ◽  
Energy Intake ◽  
Cold Exposure ◽  
Energy Homeostasis ◽  
Cold Environment ◽  
Energy Demands ◽  
Acute Cold Exposure ◽  
Neuron Activation ◽  
Increase Food Intake

To maintain energy homeostasis during cold exposure, the increased energy demands of thermogenesis must be counterbalanced by increased energy intake. To investigate the neurobiological mechanisms underlying this cold-induced hyperphagia, we asked whether agouti-related peptide (AgRP) neurons are activated when animals are placed in a cold environment and, if so, whether this response is required for the associated hyperphagia. We report that AgRP-neuron activation occurs rapidly upon acute cold exposure, as do increases of both energy expenditure and energy intake, suggesting the mere perception of cold is sufficient to engage each of these responses. We further report that silencing of AgRP neurons selectively blocks the effect of cold exposure to increase food intake but has no effect on energy expenditure. Together, these findings establish a physiologically important role for AgRP neurons in the hyperphagic response to cold exposure.

Important role of glucagon during exercise in diabetic dogs

1985 ◽  
Vol 59 (4) ◽  
pp. 1272-1281 ◽  
Author(s):  
D. H. Wasserman ◽  
H. L. Lickley ◽  
M. Vranic
Keyword(s):  
Plasma Glucose ◽  
Hepatic Glucose Production ◽  
Glucose Production ◽  
Immunoreactive Insulin ◽  
Metabolic Clearance ◽  
Glucose Levels ◽  
Lower Glucose ◽  
Diabetic Dogs ◽  
Lactate Levels

To define the role of immunoreactive glucagon (IRG) during exercise in diabetes, 12 insulin-deprived alloxan-diabetic (A-D) dogs were run for 90 min (100 m/min, 12 degrees) with or without somatostatin (St 0.5 microgram . kg-1 . min-1). Compared with normal dogs, A-D dogs were characterized by similar hepatic glucose production (Ra), lower glucose metabolic clearance, and higher plasma glucose and free fatty acid levels during rest and exercise. In A-D dogs IRG was greater at rest and exhibited a threefold greater exercise increment than controls, whereas immunoreactive insulin (IRI) was reduced by 68% at rest but had similar values to controls during exercise. Basal norepinephrine, epinephrine, cortisol, and lactate levels were similar in normal and A-D dogs. However, exercise increments in norepinephrine, cortisol, and lactate were higher in A-D dogs. When St was infused during exercise in the A-D dogs, IRG was suppressed by 432 +/- 146 pg/ml below basal and far below the exercise response in A-D controls (delta = 645 +/- 153 pg/ml). IRI was reduced by 1.8 +/- 0.2 microU/ml with St. With IRG suppression the increase in Ra seen in exercising A-D controls (delta = 4.8 +/- 1.6 mg . kg-1 . min-1) was virtually abolished, and glycemia fell by 104 to 133 +/- 37 mg/dl. Owing to this decrease in glycemia, the increase in glucose disappearance was attenuated. Despite the large fall in glucose during IRG suppression, counterregulatory increases were not excessive compared with A-D controls. In fact, as glucose levels approached euglycemia, the increments in norepinephrine and cortisol were reduced to levels similar to those seen in normal exercising dogs. In conclusion, IRG suppression during exercise in A-D dogs almost completely obviated the increase in Ra, resulting in a large decrease in plasma glucose. Despite this large fall in glucose, there was no excess counterregulation, since glucose concentrations never reached the hypoglycemic range.

Brown fat mediates increased energy expenditure of cold-exposed overfed neonatal rats

1986 ◽  
Vol 251 (3) ◽  
pp. R518-R524
Author(s):  
B. J. Moore ◽  
J. S. Stern ◽  
B. A. Horwitz
Keyword(s):  
Energy Expenditure ◽  
Cold Exposure ◽  
Rapid Onset ◽  
Brown Fat ◽  
O2 Consumption ◽  
Neonatal Rats ◽  
Ambient Temperatures ◽  
Rat Pups ◽  
Acute Cold Exposure ◽  
Brown Adipose

Genetically lean rat pups, overfed by being raised in small litters of three from day 1 postpartum, rapidly become obese compared with pups raised in standard sized litters of eight. Because of the rapid onset of their obesity, we expected that overfed pups would exhibit defective brown fat thermogenesis as is seen in neonatal genetically obese rodents. O2 consumption (VO2) was measured in 2-, 4-, 6-, and 8-day-old homozygous lean (Fa/Fa) Zucker pups from each treatment. We determined minimum rate of VO2 at thermoneutrality and maximum VO2 in response to progressively colder ambient temperatures. Overfed pups were fatter than standard-fed pups (P less than 0.001). But contrary to our prediction, overfed pups had a significantly increased maximum VO2 in response to acute cold exposure. To test the hypothesis that brown fat mediated the increased VO2 in the overfed pups, scapular brown fat lipectomies were performed on a new group of overfed pups at 2 days of age and compared with sham-operated littermate controls. On day 8, no differences in minimum VO2 were seen at thermoneutrality when brown fat is turned off. But maximum VO2 in response to cold, when brown fat is turned on maximally, was significantly reduced in the lipectomized overfed pups compared with sham-operated overfed littermates. These data suggest that manipulations of diet, accomplished by raising pups in small litters, can increase brown fat thermogenic function. The results of the lipectomy experiment imply that brown adipose tissue is a primary mediator of the increased energy expenditure in response to acute cold exposure in the overfed pups.

Variation of plasma ketones and free fatty acids during acute cold exposure in man

1965 ◽  
Vol 20 (1) ◽  
pp. 56-60 ◽  
Author(s):  
Peter G. Hanson ◽  
Robert E. Johnson
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
Cold Exposure ◽  
Ketone Bodies ◽  
Control Period ◽  
Exposure Period ◽  
Nonesterified Fatty Acids ◽  
Acute Cold Exposure ◽  
Plasma Ffa ◽  
And Control

We have studied the magnitude of ketosis induced during acute cold exposure. Plasma and urinary ketone bodies and plasma free fatty acids (FFA) were followed in four healthy young men at rest during a 90-min period of seminude exposure to 0 C in still air. This period was followed by 4 hr of recovery at 25 C. Each subject served as his own control throughout an experimental sequence in which one cold-exposure and corresponding control period (25 C) were experienced each week for 3 successive weeks. The subjects were in a fasting state but with water ad libitum beginning 12 hr prior to the experiment. Light weight clothing was worn during recovery and control periods. The combined group data show a significant increase in plasma FFA during cold exposure as compared with similar control periods. Although true hyperketonemia or hyperketonuria did not develop, the levels of plasma ketones are elevated in the cold-exposure period of the first week. During the second and third week there is no difference between the cold and control plasma ketone concentration. The data suggest that FFA is mobilized as a metabolic substrate during cold exposure and that efficient peripheral utilization of the elevated plasma FFA concentration minimizes hyperketogenesis. ketone bodies; metabolism; nonesterified fatty acids Submitted on April 27, 1964

Cold exposure reverses inhibitory effects of fasting on peripheral glucose uptake in rats

1989 ◽  
Vol 257 (1) ◽  
pp. R96-R101 ◽  
Author(s):  
H. Shibata ◽  
F. Perusse ◽  
A. Vallerand ◽  
L. J. Bukowiecki
Keyword(s):  
Glucose Uptake ◽  
Cold Exposure ◽  
Plasma Glucose ◽  
Skeletal Muscles ◽  
Inhibitory Effects ◽  
Peripheral Tissues ◽  
Glucose Levels ◽  
Brown Adipose ◽  
Order Of Magnitude ◽  
Fasted Rats

The effects of fasting and cold exposure on glucose uptake in skeletal muscles (tibialis anterior, quadriceps, and soleus), heart, and brown adipose tissue (BAT) were studied in conscious rats. Glucose uptake was estimated by determining the glucose metabolic index of individual tissues using the 2-[3H]deoxyglucose method. Fasting for 18 h at 25 degrees C decreased plasma glucose levels (-40%) and glucose uptake in heart (-95%) and skeletal muscles (-64-90%) but did not significantly affect glucose uptake in BAT. Fasting for 48 h did not further decrease these parameters. On the other hand, cold exposure (48 h at 5 degrees C) of fed animals did not alter plasma glucose levels but increased glucose uptake in heart (73%), skeletal muscles (126-326%), and particularly in BAT (95-fold). Remarkably, cold exposure stimulated glucose uptake in BAT and skeletal muscles of 18-h fasted rats by the same order of magnitude as in fed animals (percentagewise), thereby indicating that glucose represents an essential metabolite for shivering (muscles) and nonshivering (BAT) thermogeneses. In the heart of starved animals, the cold-induced increase in glucose uptake was even more important (8-fold) than in fed animals. Considering that cold exposure of fasted rats results in a severe insulinopenia, it is suggested that cold exposure stimulates glucose uptake in peripheral tissues primarily by enhancing glucose oxidation via insulin-independent pathways.

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