Altered Expression of SOCS3 in the Hypothalamic Arcuate Nucleus during Seasonal Body Mass Changes in the Field Vole, Microtus agrestis

2007 ◽  
Vol 19 (2) ◽  
pp. 83-94 ◽  
Author(s):  
E. Król ◽  
A. Tups ◽  
Z. A. Archer ◽  
A. W. Ross ◽  
K. M. Moar ◽  
...  
Keyword(s):  
Body Mass ◽  
Arcuate Nucleus ◽  
Microtus Agrestis ◽  
Field Vole ◽  
Altered Expression ◽  
Hypothalamic Arcuate Nucleus ◽  
Body Mass Changes

scholarly journals Regulation of body mass and adiposity in the field vole, Microtus agrestis: a model of leptin resistance

2007 ◽  
Vol 192 (2) ◽  
pp. 271-278 ◽  
Author(s):  
Elżbieta Król ◽  
John R Speakman
Keyword(s):  
Food Intake ◽  
Body Mass ◽  
Arcuate Nucleus ◽  
Leptin Resistance ◽  
Microtus Agrestis ◽  
Loss Of Control ◽  
Digestive Efficiency ◽  
Leptin Sensitivity ◽  
Efficiency Measures ◽  
Hypothalamic Arcuate Nucleus

Adult mammals are typically highly resistant to perturbations in their energy balance. In obese humans, however, this control appears to be lost. Apart from a few exceptional cases, this loss of control occurs despite appropriate levels of circulating leptin – suggesting that elevated adiposity may be a consequence of failure to respond to the leptin signal: leptin resistance. When cold-acclimated male field voles (Microtus agrestis) are transferred from short (SD, 8 h light) to long (LD, 16 h light) photoperiods, they increase dramatically in body mass and fatness for about 4 weeks. After this period, their mass stabilizes at a new plateau about 25% higher than animals maintained in SD. The increase in adiposity is not caused by significant increases in food intake, but reflects an increase in digestive efficiency. Measures of circulating leptin reveal that the increased adiposity is matched by increased circulating leptin. By infusing voles with exogenous leptin, we have demonstrated that SD voles are leptin sensitive (reducing both body mass and food intake), whereas LD animals are leptin resistant. Voles may therefore be a useful model for understanding the process of leptin resistance. The change in leptin sensitivity in voles was not associated with changes in the levels of gene expression of the orexogenic or anorexogenic neuropeptides, such as neuropeptide Y, agouti-related peptide, POMC and cocaine- and amphetamine-regulated transcript, measured in the hypothalamic arcuate nucleus (ARC). During the phase that body mass was increasing, however, there was a transient increase in the ARC expression of suppressor of cytokine signalling-3 (SOCS3). These data suggest that the changes in the expression of SOCS3 in the ARC may be involved in leptin resistance. However, the mechanism by which these changes may be linked to alterations in digestive efficiency that underpin the changes in adiposity, or how the differences are signalled by changes in photoperiod, remains unclear.

Must Desert Chukars (Alectoris chukar sinaica) Drink Water? Water Influx and Body Mass Changes in Response to Dietary Water Content

The Auk ◽  
1984 ◽  
Vol 101 (1) ◽  
pp. 47-52 ◽  
Author(s):  
A. Allan Degen ◽  
Berry Pinshow ◽  
Peter J. Shaw
Keyword(s):  
Drinking Water ◽  
Body Mass ◽  
Free Water ◽  
Energy Requirements ◽  
Fresh Matter ◽  
Alectoris Chukar ◽  
Water Influx ◽  
Green Vegetation ◽  
Body Mass Changes ◽  
Vegetation Water

Abstract The Chukar subspecies Alectoris chukar sinaica inhabits the Negev desert, which is characterized by hot, dry summers, and little winter rainfall. Vegetation is dry and dormant during the summer and autumn; green, succulent vegetation is available following winter rain. We studied whether or not and under what dietary conditions Chukars require drinking water. Four groups of Chukars in an outdoor aviary received either a dry ration + water, a dry ration + green vegetation, a dry ration + green vegetation + water, or green vegetation only. The birds offered only greens lost 15% of their body mass in the first 8 days and 2.9% over the next 6 days, while birds on the other three treatments maintained body mass. The birds receiving only greens had the highest total body water to body mass ratio and the highest water influx. We concluded that the Chukars receiving only green vegetation met their water requirements but not their maintenance energy requirements. Chukars fulfilled both their water and energy requirements on a dry ration + green vegetation (without drinking water); the green vegetation comprised approximately 60% of their total fresh matter intake, or 26% of their total dry matter intake. Our analysis suggests that wild desert Chukars do not require drinking water from early winter to late spring, when succulent forage is available, but probably need free water during summer and autumn, when the bulk of their diet is seeds.

Survivors of acute lymphoblastic leukemia and body mass changes

2009 ◽  
Vol 9 (1) ◽  
pp. 65-77 ◽  
Author(s):  
Szymon Skoczen ◽  
Marcin Surmiak ◽  
Wojciech Strojny
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Body Mass ◽  
Lymphoblastic Leukemia ◽  
Body Mass Changes

The analysis of immunological profiles in wild animals: a case study on immunodynamics in the field vole, Microtus agrestis

2010 ◽  
Vol 20 (5) ◽  
pp. 893-909 ◽  
Author(s):  
JOSEPH A. JACKSON ◽  
MICHAEL BEGON ◽  
RICHARD BIRTLES ◽  
STEVE PATERSON ◽  
IDA M. FRIBERG ◽  
...  
Keyword(s):  
Microtus Agrestis ◽  
Wild Animals ◽  
Field Vole

Diet-derived nutrients mediate the inhibition of hypothalamic NPY neurons in the arcuate nucleus of mice during refeeding

2009 ◽  
Vol 297 (1) ◽  
pp. R100-R110 ◽  
Author(s):  
Csilla Becskei ◽  
Thomas A. Lutz ◽  
Thomas Riediger
Keyword(s):  
Neuropeptide Y ◽  
Arcuate Nucleus ◽  
Peptide Yy ◽  
Small Reduction ◽  
Hypothalamic Arcuate Nucleus ◽  
Ad Libitum ◽  
Fos Expression

Fasting activates orexigenic neuropeptide Y neurons in the hypothalamic arcuate nucleus (ARC) of mice, which is reversed by 2 h refeeding with standard chow. Here, we investigated the contribution of diet-derived macronutrients and anorectic hormones to the reversal of the fasting-induced ARC activation during 2 h refeeding. Refeeding of 12-h-fasted mice with a cellulose-based, noncaloric mash induced only a small reduction in c-Fos expression. Refeeding with diets, containing carbohydrates, protein, or fat alone reversed it similar to chow; however, this effect depended on the amount of intake. The fasting-induced ARC activation was unchanged by subcutaneously injected amylin, CCK (both 20 μg/kg), insulin (0.2 U/kg and 0.05 U/kg) or leptin (2.6 mg/kg). Insulin and leptin had no effect on c-Fos expression in neuropeptide Y or proopiomelanocortin-containing ARC neurons. Interestingly, CCK but not amylin reduced the ghrelin-induced c-Fos expression in the ARC in ad libitum-fed mice, suggesting that CCK may inhibit orexigenic ARC neurons when acting together with other feeding-related signals. We conclude that all three macronutrients and also non-nutritive, ingestion-dependent signals contribute to an inhibition of orexigenic ARC neurons after refeeding. Similar to the previously demonstrated inhibitory in vivo action of peptide YY, CCK may be a postprandial mediator of ARC inhibition.

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