scholarly journals Photoperiod Influences the Effects of Exercise and Food Restriction on an Antigen-Specific Immune Response in Siberian Hamsters

Endocrinology ◽  
2004 ◽  
Vol 145 (2) ◽  
pp. 556-564 ◽  
Author(s):  
Staci D. Bilbo ◽  
Randy J. Nelson
Keyword(s):  
Body Mass ◽  
Food Restriction ◽  
Severity Of Illness ◽  
Reproductive Function ◽  
Delayed Type Hypersensitivity ◽  
Siberian Hamsters ◽  
Trade Offs ◽  
Access To Food ◽  
Short Days ◽  
Activity Condition

Abstract Environmental conditions influence the onset and severity of illness and infection and may compromise survival. Energetically challenging conditions during winter may directly induce death through hypothermia, starvation, or shock. The ability to forecast and prepare for the arrival of challenging conditions associated with winter (e.g. low temperatures, decreased food) likely confers survival advantages. Siberian hamsters (Phodopus sungorus) stop reproduction and reduce body mass (∼25%) during short, winter-like day lengths, resulting in energetic savings. Hamsters also increase circulating glucocorticoids and lymphocytes (e.g. T cells, NK cells), and exhibit enhanced antigen-specific delayed-type-hypersensitivity (DTH) responses in the skin during short days (SDs). We tested the hypothesis that Siberian hamsters use SD lengths to signal the onset of winter to mediate the energetic trade-offs among body mass, reproductive function, and immune function. Long-day (LD; 16 h light, 8 h dark) and SD (8 h light, 16 h dark) hamsters were either food restricted (25%) or provided ad libitum (ad lib) food for 4 wk; half of all hamsters in each food condition had voluntary access to a running wheel, and half remained sedentary. SD hamsters enhanced DTH responses compared with LD hamsters under sedentary ad lib conditions. Exercise enhanced DTH in LD hamsters regardless of food intake. Furthermore, food-restriction did not significantly influence DTH in LD hamsters. In contrast, food-restriction suppressed DTH in SD hamsters regardless of activity condition, and exercise modestly enhanced DTH only in SD hamsters with ad lib access to food. In sum, moderate energetic deficiency suppressed DTH in SD (but not LD) hamsters, and this suggests that hamsters may have evolved to enhance immune responses during winter in preparation for increased metabolic stressors.

scholarly journals Limited Access to Food and Physiological Trade‐Offs in a Long‐Distance Migrant Shorebird. I. Energy Metabolism, Behavior, and Body‐Mass Regulation

2009 ◽  
Vol 82 (5) ◽  
pp. 549-560 ◽  
Author(s):  
François Vézina ◽  
Magali Petit ◽  
Deborah M. Buehler ◽  
Anne Dekinga ◽  
Theunis Piersma
Keyword(s):  
Energy Metabolism ◽  
Body Mass ◽  
Long Distance ◽  
Limited Access ◽  
Body Mass Regulation ◽  
Trade Offs ◽  
Access To Food

Short-day-like body weight changes do not prevent fat pad compensation after lipectomy in Siberian hamsters

1997 ◽  
Vol 272 (1) ◽  
pp. R68-R77 ◽  
Author(s):  
M. M. Mauer ◽  
T. J. Bartness
Keyword(s):  
Body Weight ◽  
Food Restriction ◽  
Adipocyte Size ◽  
Weight Changes ◽  
Fat Pad ◽  
Body Weight Changes ◽  
Siberian Hamsters ◽  
Long Day ◽  
Long Duration ◽  
Short Days

Long-day (LD)-housed Siberian hamsters show compensatory increases in white adipose tissue (WAT) weight after lipectomy, whereas hamsters exposed to short days (SDs) for a long duration (22 wk) do not. We tested whether SD-induced body weight changes prevent fat pad compensation after lipectomy. In experiment 1, hamsters with lesions of the paraventricular nucleus of the hypothalamus (PVNx) rapidly increased body weight similarly to 22-wk SD-exposed hamsters. In experiment 2, LD-housed hamsters were food restricted for 22 wk and then pair fed with SD-housed hamsters for 12 wk to produce body weight changes mimicking those of ad libitum-fed SD-exposed animals. Epididymal WAT (EWAT) lipectomy (EWATx) of PVNx or food-restricted hamsters elicited compensatory increases in retroperitoneal and inguinal WAT (RWAT and IWAT) weights. Unlike other fat pads, EWAT was less affected by food restriction or PVNx than by SD exposure. In general, food restriction decreased adipocyte number, whereas SD exposure decreased adipocyte size. PVNx increased RWAT adipocyte size and IWAT adipocyte number. These results suggest that the lack of body fat compensation by EWATx hamsters exposed to SDs for a long duration is due to SD-associated responses other than body weight changes per se.

Daily torpor in the absence of the suprachiasmatic nucleus in Siberian hamsters

1992 ◽  
Vol 263 (2) ◽  
pp. R353-R362 ◽  
Author(s):  
N. F. Ruby ◽  
I. Zucker
Keyword(s):  
Suprachiasmatic Nucleus ◽  
Food Restriction ◽  
Temporal Organization ◽  
Daily Torpor ◽  
Short Day ◽  
Siberian Hamsters ◽  
Random Fashion ◽  
Before And After ◽  
Ad Libitum ◽  
Short Days

Siberian hamsters express torpor spontaneously after several weeks of exposure to short days. In long days, torpor is expressed only when food intake is restricted. Hamsters maintained in a long photoperiod (16 h light/day) at 15 degrees C expressed daily torpor during food restriction both before and after bilateral ablation of the suprachiasmatic nucleus (SCN). Hamsters housed in short days (8 h light/day, ambient temperature 15 degrees C) and fed ad libitum displayed torpor before, but not after, ablation of the SCN (SCNX). Torpor was reinstated in all short-day SCNX hamsters during postoperative food restriction and persisted in several animals even after ad libitum feeding was reinstated. Torpor was entrained to the light-dark cycle in both long- and short-day hamsters preoperatively but appeared to occur in a temporally random fashion in SCNX animals. SCNX hamsters, unlike control animals, displayed multiple torpor bouts per 24 h. The SCN is not essential for the expression of torpor but plays a crucial role in its temporal organization.

Butyric acid suppresses palatable food consumption in Siberian hamsters (Phodopus sungorus) housed in short, but not long, photoperiods

2009 ◽  
Vol 87 (9) ◽  
pp. 749-754
Author(s):  
Joanna L. Workman ◽  
Eric M. Johnson ◽  
Lynn B. Martin ◽  
Randy J. Nelson
Keyword(s):  
Food Consumption ◽  
Butyric Acid ◽  
Food Restriction ◽  
Skim Milk ◽  
Phodopus Sungorus ◽  
Milk Consumption ◽  
Palatable Food ◽  
Short Day ◽  
Siberian Hamsters ◽  
Short Days

Short days induce winter-like adaptations in small mammals such as Siberian hamsters ( Phodopus sungorus (Pallas, 1773)). Specifically, hamsters adjust food consumption, metabolic processes, and immune function to optimize energetic needs and promote winter survival. One potentially inexpensive behavioral adaptation to increase survival is avoidance of infection. We tested the hypothesis that photoperiod affects avoidance of potentially infected food. In experiment 1, hamsters were weaned into either short or long days with ad libitum food. Three weeks later, hamsters were presented with either skim milk treated with butyric acid (2%), a bacterial product that serves as a potent cue of spoilage, or unadulterated skim milk; consumption was measured. After milk presentation, blood samples were obtained to assess cortisol. In experiment 2, skim-milk consumption was again assessed after 3 weeks in either short or long days. In experiment 3, we tested the hypothesis that food avoidance was due to photoperiod-induced differential neophobia. Short-day hamsters increased milk consumption, which was blocked by butyric acid. Short days increased cortisol concentrations; neither food restriction nor butyric acid affected cortisol concentrations. Photoperiod did not alter neophobic responses. These experiments suggest that short-day hamsters avoid food treated with butyric acid possibly as an adaptive trait to avoid costly winter infections.

Role of area postrema in control of torpor in Siberian hamsters

2000 ◽  
Vol 279 (2) ◽  
pp. R591-R598 ◽  
Author(s):  
Helen H. Bae ◽  
Juliet L. Stamper ◽  
Eric C. Heydorn ◽  
Irving Zucker ◽  
John Dark
Keyword(s):  
Food Intake ◽  
Food Restriction ◽  
Area Postrema ◽  
Solitary Tract ◽  
Metabolic Fuel ◽  
Short Day ◽  
Siberian Hamsters ◽  
Metabolic Challenge ◽  
Short Days

Siberian hamsters undergo torpor during the short days of winter and in response to glucoprivation or food restriction. We tested whether the area postrema and the adjacent nucleus of the solitary tract (hereafter the AP), which monitor metabolic fuel availability, also control the onset of torpor. Siberian hamsters that had manifested torpor spontaneously or had entered torpor in response to 2-deoxy-d-glucose (2-DG) treatment were subjected to area postrema ablations (APx). Hamsters continued to display torpor postoperatively; most features of torpor were unaffected by APx. The AP is not necessary for expression of torpor elicited by short day lengths or metabolic challenge. In contrast, decreases in food intake manifested by hamsters treated with 2-DG were counteracted by APx. In Siberian hamsters, the AP appears to mediate effects of 2-DG on food intake but not torpor.

Torpor in lactating Siberian hamsters subjected to glucoprivation

1998 ◽  
Vol 274 (1) ◽  
pp. R46-R51 ◽  
Author(s):  
Juliet L. Stamper ◽  
Irving Zucker ◽  
Daniel A. Lewis ◽  
John Dark
Keyword(s):  
Body Mass ◽  
Food Deprivation ◽  
Food Restriction ◽  
Rodent Species ◽  
Daily Torpor ◽  
Siberian Hamsters

Daily torpor has never been reported for any rodent species during lactation. To test whether torpor and lactation are incompatible processes, we administered 2-deoxy-d-glucose (2-DG), a glucose analog that interferes with cellular glycolysis, to Siberian hamsters during the 2nd wk postpartum. 2-DG (2,500 mg/kg of body mass) induced torpor in lactating as well as nonlactating females. Although depth of torpor did not differ between groups, duration of torpor tended to be shorter in lactating animals. Evidence of new milk bands suggests that pups were able to obtain milk from torpid dams. By contrast, dams subjected either to a combination of brief food deprivation and subsequent food restriction or just food restriction failed to display torpor, but instead cannibalized one or more pups. We conclude that torpor is possible during lactation; whether lactating dams in nature become torpid in response to energy shortages or cannibalize or abandon one or more of their offspring remains unknown.

Photoperiodic and hormonal influences on fur density and regrowth in two hamster species

2007 ◽  
Vol 293 (6) ◽  
pp. R2363-R2369 ◽  
Author(s):  
Matthew J. Paul ◽  
Nicole T. George ◽  
Irving Zucker ◽  
Matthew P. Butler
Keyword(s):  
Body Mass ◽  
Seasonal Changes ◽  
Dorsal Surface ◽  
Ventral Surface ◽  
Syrian Hamsters ◽  
Siberian Hamsters ◽  
Molting Process ◽  
Pelage Color ◽  
Common Interval ◽  
Short Days

Temperate and boreal mammals undergo seasonal changes in pelage that facilitate thermoregulation in winter and summer. We investigated photoperiodic influences on pelage characteristics of male Siberian and Syrian hamsters. Fur density (mg fur/cm2 skin) was measured by weighing the shavings of fur patches removed from the dorsal and ventral surfaces of hamsters maintained in long days (LDs) or transferred to short days (SDs). Patches were reshaved 3 wk later to assess fur regrowth (mg regrown fur/cm2 skin). Fur density was greater in SD than in LD Siberian hamsters after 11 wk of differential phototreatment. The onset of increased fur density in SDs was accompanied by a transient increase in fur regrowth (11–14 wk on the dorsal surface and 7–10 and 11–14 wk on the ventral surface), suggestive of a seasonal molting process. Fur density, body mass, and pelage color of Siberian hamsters returned to values characteristic of LD males after a similar duration of prolonged (>27 wk) SD treatment and appear to be regulated by a similar or common interval-timing mechanism. In Syrian hamsters, dorsal fur density, fur regrowth, and hair lengths were greater in SD than in LD males. Castration increased and testosterone (T) treatment decreased dorsal and ventral fur regrowth in LD and SD hamsters, but the effects of T manipulations on fur density were limited to a decrease in dorsal fur density after T treatment. Decreased circulating T in SDs likely contributes to the seasonal molt of male hamsters by increasing the rate of fur growth during the transition to the winter pelage.

scholarly journals Limited Access to Food and Physiological Trade‐Offs in a Long‐Distance Migrant Shorebird. II. Constitutive Immune Function and the Acute‐Phase Response

2009 ◽  
Vol 82 (5) ◽  
pp. 561-571 ◽  
Author(s):  
Deborah M. Buehler ◽  
Francisco Encinas‐Viso ◽  
Magali Petit ◽  
François Vézina ◽  
B. Irene Tieleman ◽  
...  
Keyword(s):  
Immune Function ◽  
Acute Phase ◽  
Acute Phase Response ◽  
Phase Response ◽  
Long Distance ◽  
Limited Access ◽  
Trade Offs ◽  
Access To Food

scholarly journals The energy allocation trade-offs underlying life history traits in hypometabolic strepsirhines and other primates

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bruno Simmen ◽  
Luca Morino ◽  
Stéphane Blanc ◽  
Cécile Garcia
Keyword(s):  
Life History ◽  
Energy Expenditure ◽  
Body Mass ◽  
Life History Traits ◽  
Brain Size ◽  
Energy Allocation ◽  
Interbirth Interval ◽  
Energy Investment ◽  
Litter Mass ◽  
Trade Offs

AbstractLife history, brain size and energy expenditure scale with body mass in mammals but there is little conclusive evidence for a correlated evolution between life history and energy expenditure (either basal/resting or daily) independent of body mass. We addressed this question by examining the relationship between primate free-living daily energy expenditure (DEE) measured by doubly labeled water method (n = 18 species), life history variables (maximum lifespan, gestation and lactation duration, interbirth interval, litter mass, age at first reproduction), resting metabolic rate (RMR) and brain size. We also analyzed whether the hypometabolic primates of Madagascar (lemurs) make distinct energy allocation tradeoffs compared to other primates (monkeys and apes) with different life history traits and ecological constraints. None of the life-history traits correlated with DEE after controlling for body mass and phylogeny. In contrast, a regression model showed that DEE increased with increasing RMR and decreasing reproductive output (i.e., litter mass/interbirth interval) independent of body mass. Despite their low RMR and smaller brains, lemurs had an average DEE remarkably similar to that of haplorhines. The data suggest that lemurs have evolved energy strategies that maximize energy investment to survive in the unusually harsh and unpredictable environments of Madagascar at the expense of reproduction.

Sign in / Sign up

Export Citation Format

Share Document