Environmental influences on adiponectin levels in humans

2007 ◽  
Vol 32 (3) ◽  
pp. 505-511 ◽  
Author(s):  
Pascal Imbeault
Keyword(s):  
Fatty Acids ◽  
Weight Loss ◽  
Food Intake ◽  
Lipid Oxidation ◽  
Glucose Uptake ◽  
Cold Exposure ◽  
Skeletal Muscles ◽  
Environmental Influences ◽  
Nonesterified Fatty Acids ◽  
Glucose Output

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.

Metabolic concomitants of hypophagia during recovery from insulin-induced obesity in rats

1983 ◽  
Vol 245 (3) ◽  
pp. E211-E219 ◽  
Author(s):  
I. Ramirez ◽  
M. I. Friedman
Keyword(s):  
Fatty Acids ◽  
Weight Loss ◽  
Food Intake ◽  
Free Fatty Acids ◽  
Insulin Treatment ◽  
Liver Glycogen ◽  
Diabetic Rats ◽  
Acid Oxidation ◽  
Hepatic Fatty Acid Oxidation ◽  
Adipose Tissue Lipoprotein Lipase

Rats were given daily injections of protamine-zinc insulin (PZI) that increased food intake and body weight. Termination of insulin treatment resulted in transient hypophagia and weight loss. Simultaneously with the weight loss, plasma levels of glycerol, free fatty acids, glucose, and ketones increased, whereas adipose tissue lipoprotein lipase activity and liver glycogen decreased. These changes in food intake and metabolism after termination of PZI treatment were accentuated in streptozotocin-diabetic rats. Two antilipolytic drugs (nicotinic acid and 3,5-dimethylpyrazole) blocked the elevation in plasma glycerol while having no effect on food intake. A 1-day fast after termination of insulin treatment equalized insulin-treated and control groups for plasma glycerol and ketones and reversed group differences in free fatty acids; the elevation in plasma glucose persisted despite starvation. Following starvation, previously PZI-treated rats ate less than controls on refeeding. The results show that enhanced lipolysis does not invariably accompany hypophagia during excess weight loss and suggest that a disturbance in carbohydrate metabolism or an increase in hepatic fatty acid oxidation may underlie this decrease in food intake.

Physiological and behavioral responses to starvation in the golden hamster.

1979 ◽  
Vol 236 (2) ◽  
pp. E105 ◽  
Author(s):  
K T Borer ◽  
N Rowland ◽  
A Mirow ◽  
R C Borer ◽  
R P Kelch
Keyword(s):  
Fatty Acids ◽  
Weight Loss ◽  
Weight Gain ◽  
Food Intake ◽  
Behavioral Responses ◽  
Blood Metabolites ◽  
Serum Concentrations ◽  
Weight Losses ◽  
Beta Hydroxybutyrate ◽  
Access To Food

Physiological and behavioral responses of adult hamsters to starvation were studied by measuring food intake, weight recovery, serum concentrations of glucose, insulin, free fatty acids and beta-hydroxybutyrate, and ketonuria in animals subjected to different weight losses, diets, and durations of fast. Hamsters were debilitated by fasts longer than 12 h or leading to greater than 20% weight loss. Hamsters' feeding patterns were unmodified by fasts ranging between 5 and 12 h and showed no circadian periodicity. Hamsters predominantly recovered from weight losses without increasing their food consumption (unless they were offered a diet of pellets and seeds) and without changing their meal patterns, at a rate of weight gain proportional to the magnitude of preceding weight loss if provided with uninterrupted access to food. By 8 h of fast, blood metabolites were indicative of mobilization of body fat. Hamsters are thus behaviorally unresponsive to duration of fast, but compensate physiologically for weight losses with proportional increases in the rate of weight gain.

Cold exposure potentiates the effect of insulin on in vivo glucose uptake

1987 ◽  
Vol 253 (2) ◽  
pp. E179-E186 ◽  
Author(s):  
A. L. Vallerand ◽  
F. Perusse ◽  
L. J. Bukowiecki
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Glucose Uptake ◽  
White Adipose Tissue ◽  
Cold Exposure ◽  
Skeletal Muscles ◽  
Insulin Injection ◽  
Peripheral Tissues ◽  
Brown Adipose ◽  
Insulin Responses

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.

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.

scholarly journals Adipose Lipolysis Regulates Cardiac Glucose Uptake and Function in Mice under Cold Stress

2021 ◽  
Vol 22 (24) ◽  
pp. 13361
Author(s):  
Youngshim Choi ◽  
Hyunsu Shin ◽  
Ziwei Tang ◽  
Yute Yeh ◽  
Yinyan Ma ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Cold Stress ◽  
Glucose Uptake ◽  
Cold Exposure ◽  
Plasma Concentrations ◽  
Cardiac Metabolism ◽  
Gene Identification ◽  
Mitochondrial Oxidative Phosphorylation ◽  
Glucose Tolerant ◽  
And Function

The heart primarily uses fatty acids as energy substrates. Adipose lipolysis is a major source of fatty acids, particularly under stress conditions. In this study, we showed that mice with selective inactivation of the lipolytic coactivator comparative gene identification-58 (CGI-58) in adipose tissue (FAT-KO mice), relative to their littermate controls, had lower circulating FA levels in the fed and fasted states due to impaired adipose lipolysis. They preferentially utilized carbohydrates as energy fuels and were more insulin sensitive and glucose tolerant. Under cold stress, FAT-KO versus control mice had >10-fold increases in glucose uptake in the hearts but no increases in other tissues examined. Plasma concentrations of atrial natriuretic peptide and cardiac mRNAs for atrial and brain-type natriuretic peptides, two sensitive markers of cardiac remodeling, were also elevated. After one week of cold exposure, FAT-KO mice showed reduced cardiac expression of several mitochondrial oxidative phosphorylation proteins. After one month of cold exposure, hearts of these animals showed depressed functions, reduced SERCA2 protein, and increased proteins for MHC-β, collagen I proteins, Glut1, Glut4 and phospho-AMPK. Thus, CGI-58-dependent adipose lipolysis critically regulates cardiac metabolism and function, especially during cold adaptation. The adipose-heart axis may be targeted for the management of cardiac dysfunction.

High-altitude acclimation increases the triacylglycerol/fatty acid cycle at rest and during exercise

2001 ◽  
Vol 281 (3) ◽  
pp. E537-E544 ◽  
Author(s):  
Grant B. McClelland ◽  
Peter W. Hochachka ◽  
Shannon P. Reidy ◽  
Jean-Michel Weber
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Lipid Metabolism ◽  
Lipid Oxidation ◽  
High Altitude ◽  
Sea Level ◽  
Total Lipid ◽  
Level Control ◽  
Nonesterified Fatty Acids ◽  
Acid Cycle

High-altitude acclimation alters lipid metabolism during exercise, but it is unknown whether this involves changes in rates of lipolysis or reesterification, which form the triacylglycerol/fatty acid (TAG/FA) cycle. We combined indirect calorimetry with [2-3H]glycerol and [1-14C]palmitate infusions to simultaneously measure total lipid oxidation, lipolysis, and rate of appearance (Ra) of nonesterified fatty acids (NEFA) in high-altitude-acclimated (HA) rats exercising at 60% maximal O2 uptake (V˙o 2 max). During exercise, relative total lipid oxidation (%V˙o 2) equaled sea-level control (SL) values; however, acclimation greatly stimulated lipolysis (+75%) but had no effect on Ra NEFA. As a result, TAG/FA cycling increased (+119%), due solely to an increase in recycling (+144%) within adipocytes. There was no change in either group in these variables with the transition from rest to exercise. We conclude that, in HA, 1) acclimation is a potent stimulator of lipolysis; 2) rats do not modify TAG/FA cycling with the transition to exercise; and 3) in normoxia, HA and SL derive the same fraction of their total energy from lipids and carbohydrates.

Plasma glucose and insulin responses to oral and intravenous glucose in cold-exposed humans

1988 ◽  
Vol 65 (6) ◽  
pp. 2395-2399 ◽  
Author(s):  
A. L. Vallerand ◽  
J. Frim ◽  
M. F. Kavanagh
Keyword(s):  
Glucose Tolerance ◽  
Glucose Uptake ◽  
Carbohydrate Metabolism ◽  
Cold Exposure ◽  
Plasma Glucose ◽  
Hepatic Glucose Output ◽  
Hepatic Glucose ◽  
Oral Gtt ◽  
Glucose Output ◽  
Insulin Responses

Although glucose tolerance and skeletal muscle glucose uptake are markedly improved by cold exposure in animals, little is known about such responses in humans. This study used two variations of a glucose tolerance test (GTT) to investigate changes in carbohydrate metabolism in healthy males during nude exposure to cold. In experiment 1, an oral GTT was performed in the cold and in the warm (3 h at 10 or 29 degrees C). To bypass the gastrointestinal tract, and to suppress hepatic glucose output, a second experiment was carried out as described above, using an intravenous GTT. Even though cold exposure raised metabolic rate greater than 2.5 times, plasma glucose and insulin responses to an oral GTT remained unaltered. In contrast, cold exposure reduced the entire plasma glucose profile as a function of time during the intravenous GTT (P less than 0.05), as plasma glucose was returned to basal levels within 1 h in comparison to a full 2 h in the warm, despite low insulin levels. The results of the intravenous GTT demonstrate that even with low insulin levels, carbohydrate metabolism is increased in cold-exposed males. This effect could be masked in the oral GTT by gastrointestinal factors and a high hepatic glucose output. Cold exposure may enhance insulin sensitivity and/or responsiveness for glucose uptake, mainly in shivering skeletal muscles.

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