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

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.

1994 ◽  
Vol 266 (3) ◽  
pp. R914-R920 ◽  
Author(s):  
X. Liu ◽  
F. Perusse ◽  
L. J. Bukowiecki

Cold exposure activates the sympathetic nervous system and markedly stimulates glucose uptake in rat peripheral tissues [A. L. Vallerand, F. Perusse, and L. J. Bukowiecki. Am. J. Physiol 259 (Regulatory Integrative Comp. Physiol. 28): R1043-R1049, 1990]. To test whether norepinephrine (NE) mimics the effects of cold exposure, we estimated the effects of chronic NE treatment on tissue glucose uptake by determining the glucose metabolic index using the 2-[1,2-3H(N)]deoxy-D-glucose method. NE was administered in conscious rats at various doses (ranging from 1.9 to 25.1 nmol.kg-1.min-1) during 4 days via minipumps implanted subcutaneously. At doses > 10 nmol.kg-1.min-1, NE maximally stimulated glucose uptake in interscapular brown adipose tissue (approximately 50 times above controls) and epididymal white adipose tissue (approximately 3 times above controls). NE infusion (18.8 nmol.kg-1.min-1) increased the circulating levels of NE from 1.1 +/- 0.1 to 19.2 +/- 0.4 nM (P < 0.001), which is in the range of concentrations for the stimulatory effects of NE on glucose uptake in isolated brown adipocytes. At all concentrations tested, NE infusion did not stimulate glucose uptake in the heart and skeletal muscles. NE treatment did not significantly alter plasma insulin or glucose levels but increased the concentration of circulating free fatty acids. The capacity of brown adipose tissue for NE stimulation of glucose uptake (expressed per g of tissue) was much higher than that of white adipose tissue (100 times), various types of white or red skeletal muscles (10-80 times), or the heart (3-4 times).(ABSTRACT TRUNCATED AT 250 WORDS)


1987 ◽  
Vol 253 (2) ◽  
pp. E179-E186 ◽  
Author(s):  
A. L. Vallerand ◽  
F. Perusse ◽  
L. J. Bukowiecki

The effects of cold exposure (48 h at 4 degrees C) and insulin injection (0.5 U/kg iv) on the rates of net 2-[3H]deoxyglucose uptake (Ki) in peripheral tissues were investigated in warm-acclimated rats (25 degrees C). Cold exposure and insulin treatment independently increased Ki values in skeletal muscles (soleus, extensor digitorum longus, and vastus lateralis), heart, white adipose tissue (subcutaneous, gonadal, and retroperitoneal), and brown adipose tissue (P less than 0.01). The effects of cold exposure were particularly evident in brown adipose tissue where the Ki increased greater than 100 times. When the two treatments were combined (insulin injection in cold-exposed rats), it was found that cold exposure synergistically enhanced the maximal insulin responses for glucose uptake in brown adipose tissue, all white adipose tissue depots, and skeletal muscles investigated. The results indicate that cold exposure induces an "insulin-like" effect on Ki that does not appear to be specifically associated with shivering thermogenesis in skeletal muscles, because that effect was observed in all insulin-sensitive tissues. The data also demonstrate that cold exposure significantly potentiates the maximal insulin responses for glucose uptake in the same tissues. This potentialization may result from an enhanced responsiveness of peripheral tissues to insulin, possibly occurring at metabolic steps lying beyond the insulin receptor and an increased tissue blood flow augmenting glucose and insulin availability and thereby amplifying glucose uptake.


1990 ◽  
Vol 259 (5) ◽  
pp. R1043-R1049 ◽  
Author(s):  
A. L. Vallerand ◽  
F. Perusse ◽  
L. J. Bukowiecki

The effects of cold exposure on the net rates of 2-[3H]deoxy-D-glucose uptake (Ki) in rat peripheral tissues were investigated comparatively in warm- and cold-acclimated animals to determine whether cold acclimation induces regulatory alterations in glucose metabolism. Acute exposure of warm-acclimated (25 degrees C) rats to cold (48 h at 5 degrees C) markedly increased the Ki values in red and white skeletal muscles (2-5 times), in the heart (8 times), in several white adipose tissue (WAT) depots (4-20 times), and in brown adipose tissue (BAT) (110 times). After cold acclimation (3 wk at 5 degrees C), the Ki values further increased in the heart (15 times) and WAT (up to 29 times) but decreased in BAT (36 times). Remarkably, glucose uptake was still increased in muscles of cold-exposed/cold-acclimated animals (that do not shiver), demonstrating that enhanced glucose uptake may occur in muscles in the absence of shivering thermogenesis (or contractile activity). When cold-acclimated rats were returned to the warm for 18 h, the Ki values of all tissues, except WAT, returned to control levels. Cold exposure synergistically potentiated the stimulation of tissue glucose uptake induced by a maximal effective dose of insulin (0.5 U/kg iv) in warm- as well as in cold-acclimated animals.(ABSTRACT TRUNCATED AT 250 WORDS)


1982 ◽  
Vol 242 (1) ◽  
pp. R109-R115 ◽  
Author(s):  
O. L. Smith ◽  
S. B. Davidson

Acute cold exposure of normal rats (4 degrees C for 24 h) increased food intake, reduced plasma glucose and liver glycogen, caused a small increase in plasma free fatty acids, and lowered serum insulin concentration by 50%. In fasted rats, cold raised fatty acid levels twice as high as in fed. In mild diabetes (40 mg/kg streptozotocin iv) cold reduced glucose levels in blood and urine, but in severe diabetes (90 mg/kg) cold aggravated hyperglycemia and ketonuria. Changes in muscle glucose utilization were also studied, after evisceration (functional hepatectomy) of rats from each group. Uptake was calculated from the fall in plasma glucose concentration during the 4-h period after a load of 50% glucose iv. Cold normally increased uptake 67%, but it failed to do so in fasted rats. In diabetic rats, cold enhanced uptake, but only if the disease were mild or insulin controlled. Sensitivity of uptake to insulin was unaffected by cold. The results suggest that shivering thermogenesis, like exercise, can promote glucose uptake by skeletal muscle, if enough insulin is present to prevent excess mobilization of lipid substrates.


1989 ◽  
Vol 67 (4) ◽  
pp. 382-393 ◽  
Author(s):  
Ludwik Jan Bukowiecki

The effects of cold exposure, exercise training, and diet (high fat versus high carbohydrate) on glucose tolerance and glucose metabolism in rat peripheral tissues will be briefly reviewed. Stimulation of energy expenditure by cold exposure (4 °C) or exercise training generally leads to decreased plasma insulin levels and to an improvement in glucose tolerance, suggesting that insulin action on peripheral tissues is increased when energy expenditure is stimulated. On the contrary, feeding high-fat diets to sedentary rats living in the warm (25 °C) induces hyperinsulinemia and insulin resistance resulting in a marked deterioration of glucose tolerance. Nevertheless, cold exposure reverses the diabetogenic effects of high-fat feeding, demonstrating that nutrition-induced insulin resistance is amplified in sedentary animals living at temperatures close to thermoneutrality. Radioactive tracer studies of 2-deoxyglucose uptake in peripheral tissues revealed that cold exposure synergistically potentiates the effects of insulin on glucose uptake in skeletal muscles as well as in white and brown adipose tissues. However, more recent data showed that cold exposure improves glucose tolerance and stimulates glucose uptake in starved animals (ie., in the virtual absence of circulating insulin) nearly by the same order of magnitude as in fed animals. It is therefore concluded that cold exposure, and possibly also exercise, improve glucose tolerance and stimulate glucose uptake in peripheral tissues primarily by enhancing glucose oxidation via insulin-independent pathways, and secondarily by increasing the responsiveness of peripheral tissues to insulin.Key words: insulin, brown adipose tissue, skeletal muscle, 2-deoxyglucose, diabetes.


2018 ◽  
Vol 59 (4) ◽  
pp. 706-713 ◽  
Author(s):  
Mikael Larsson ◽  
Christopher M. Allan ◽  
Patrick J. Heizer ◽  
Yiping Tu ◽  
Norma P. Sandoval ◽  
...  

Glycosylphosphatidylinositol-anchored high density lipoprotein–binding protein 1 (GPIHBP1), an endothelial cell protein, binds LPL in the subendothelial spaces and transports it to the capillary lumen. In Gpihbp1−/− mice, LPL remains stranded in the subendothelial spaces, causing hypertriglyceridemia, but how Gpihbp1−/− mice respond to metabolic stress (e.g., cold exposure) has never been studied. In wild-type mice, cold exposure increases LPL-mediated processing of triglyceride-rich lipoproteins (TRLs) in brown adipose tissue (BAT), providing fuel for thermogenesis and leading to lower plasma triglyceride levels. We suspected that defective TRL processing in Gpihbp1−/− mice might impair thermogenesis and blunt the fall in plasma triglyceride levels. Indeed, Gpihbp1−/− mice exhibited cold intolerance, but the effects on plasma triglyceride levels were paradoxical. Rather than falling, the plasma triglyceride levels increased sharply (from ∼4,000 to ∼15,000 mg/dl), likely because fatty acid release by peripheral tissues drives hepatic production of TRLs that cannot be processed. We predicted that the sharp increase in plasma triglyceride levels would not occur in Gpihbp1−/−Angptl4−/− mice, where LPL activity is higher and baseline plasma triglyceride levels are lower. Indeed, the plasma triglyceride levels in Gpihbp1−/−Angptl4−/− mice fell during cold exposure. Metabolic studies revealed increased levels of TRL processing in the BAT of Gpihbp1−/−Angptl4−/− mice.


1983 ◽  
Vol 245 (2) ◽  
pp. E148-E154 ◽  
Author(s):  
J. B. Young ◽  
L. Landsberg

The genetically obese (ob/ob) mouse exhibits defective thermoregulatory responses to cold exposure. Pathophysiological explanations for this phenomenon have focused on abnormalities in intracellular metabolism or insensitivity of peripheral tissues to the thermogenic effects of catecholamines. Because the sympathetic nervous system (SNS) is subject to feedback regulation, a peripheral impairment in thermogenesis should be associated with a compensatory increase in SNS activity. To examine SNS activity in the ob/ob mouse, norepinephrine (NE) turnover was measured in heart and interscapular brown adipose tissue (IBAT) of ob/ob and lean mice. The results from studies utilizing radiolabeled NE or inhibition of NE biosynthesis with alpha-methyl-p-tyrosine to measure NE turnover demonstrated reductions in SNS activity of 33-56% in heart and of 45-73% in IBAT in ob/ob mice at ambient temperature (22 degrees C) compared with measurements in lean controls. During cold exposure (4 degrees C) NE turnover increased in heart and IBAT to a similar extent in both ob/ob and lean mice, but NE turnover rates in heart, and probably in IBAT as well, remained lower in the obese mice than in the lean despite the gradual development of hypothermia in the ob/ob mice during this period. Administration of naltrexone, a long-acting opiate antagonist, failed to reverse the suppression of SNS activity observed in the ob/ob mice. These data indicate that diminished SNS activity in ob/ob mice may be an additional factor contributing to the defective thermogenesis characteristic of these animals.


2007 ◽  
Vol 32 (3) ◽  
pp. 505-511 ◽  
Author(s):  
Pascal Imbeault

In addition to its classic role in the storage and release of nonesterified fatty acids, the adipocyte is now recognized as a critical source of many endocrine signals. Of these signals, adiponectin has been found to promote lipid oxidation and glucose uptake in skeletal muscles and to reduce glucose output in the liver. Because of the effects of adiponectin on these organs, the search for factors or conditions that could positively influence the synthesis of this adipocyte-derived protein has drawn a great deal of interest. This brief review explores the effects of environmental influences such as weight loss, acute food intake, exercise, and cold exposure on circulating adiponectin levels in humans.


PLoS ONE ◽  
2011 ◽  
Vol 6 (7) ◽  
pp. e22510 ◽  
Author(s):  
Anette I. Öberg ◽  
Kamal Yassin ◽  
Robert I. Csikasz ◽  
Nodi Dehvari ◽  
Irina G. Shabalina ◽  
...  

Metabolism ◽  
2005 ◽  
Vol 54 (11) ◽  
pp. 1420-1427 ◽  
Author(s):  
Luis D.M.C.-B. Ferreira ◽  
Dan Xu ◽  
T. Norman Palmer ◽  
Paul A. Fournier

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