Differential effects of food restriction on pituitary-testicular function in mice

1985 ◽  
Vol 248 (2) ◽  
pp. R181-R189 ◽  
Author(s):  
J. L. Blank ◽  
C. Desjardins
Keyword(s):  
Food Intake ◽  
Animal Models ◽  
Food Restriction ◽  
Wheel Running ◽  
Temporal Organization ◽  
Deer Mice ◽  
House Mice ◽  
Testicular Function ◽  
Running Activity ◽  
Wheel Running Activity

The reproductive responses of two species of wild rodents, house mice and deer mice, were evaluated following a 30% reduction in food intake for 5 wk. These animal models were chosen as prototypes of other rodent species because each employs unique functional adjustments when confronted with reduced resources in their natural habitats. Modest inanition failed to alter pituitary-testicular function in house mice; neither spermatogenesis nor plasma concentrations of luteinizing hormone (LH) and testosterone were modified. In sharp distinction, deer mice exposed to restricted food intake showed significant reductions in plasma LH and testosterone and an accompanying loss in spermatogenesis. Reduced food intake also caused pronounced shifts in the temporal organization and amount of wheel-running activity in both animal models, albeit in a dichotomous fashion. House mice exhibited the same amount of wheel-running activity throughout inanition, but the diel periodicity of locomotor behavior was shifted from the dark to the light period. Deer mice, in comparison, significantly curtailed wheel-running activity during the dark hours but ran in precise phase relationship with the light-dark cycle. Taken together, our results establish that the male reproductive system and its supporting neuroendocrine and behavioral correlates can be disrupted by modest levels of food restriction in certain animal models.

Interstrain differences in activity pattern, pineal function, and SCN melatonin receptor density of rats

1999 ◽  
Vol 276 (4) ◽  
pp. R1078-R1086 ◽  
Author(s):  
Gabriela Klante ◽  
Karin Secci ◽  
Mireille Masson-Pévet ◽  
Paul Pévet ◽  
Berthe Vivien-Roels ◽  
...  
Keyword(s):  
Wheel Running ◽  
Activity Patterns ◽  
Temporal Organization ◽  
Receptor Density ◽  
Melatonin Receptor ◽  
Time Pattern ◽  
Melatonin Synthesis ◽  
Running Activity ◽  
Wheel Running Activity ◽  
Inbred Rat

We investigated the possibility that strain-dependent differences in the diurnal pattern of wheel running activity rhythms are also reflected in the melatonin profiles. The inbred rat strains ACI/Ztm, BH/Ztm, and LEW/Ztm. LEW were examined for diurnal [12:12-h light-dark (LD)] wheel running activity, urinary 6-sulphatoxymelatonin (aMT6s) excretion, melatonin concentrations of plasma and pineal glands, and melatonin receptor density in the suprachiasmatic nuclei (SCN). ACI rats displayed unimodal activity patterns with a high level of activity, whereas BH and LEW rats showed multimodal activity patterns with ultradian components and reduced activity levels. In contrast, the individual daily profiles of aMT6s excretion and mean melatonin synthesis followed a unimodal time pattern in all three strains, suggesting that different output pathways of the SCN are responsible for the temporal organization of locomotor activity and pineal melatonin synthesis. In addition, melatonin synthesis at night and SCN melatonin receptor density at day were significantly higher in BH and LEW rats than in ACI rats. These results support the hypothesis of a long-term stimulating effect of melatonin on its own receptor density in the SCN.

scholarly journals Induction of IL-6 by Cytotoxic Chemotherapy Is Associated With Loss of Lean Body and Fat Mass in Tumor-free Female Mice

2014 ◽  
Vol 17 (5) ◽  
pp. 549-557 ◽  
Author(s):  
Collin R. Elsea ◽  
Janet A. Kneiss ◽  
Lisa J. Wood
Keyword(s):  
Body Composition ◽  
Food Intake ◽  
Cancer Patients ◽  
Fat Mass ◽  
Wheel Running ◽  
Cytotoxic Chemotherapy ◽  
Dependent Manner ◽  
Breast Cancer Patients ◽  
Running Activity ◽  
Wheel Running Activity

Cancer patients treated with cytotoxic chemotherapy experience fatigue and changes in body composition that can impact physical functioning and quality of life during and after treatment. Interleukin-6 (IL-6) is associated with fatigue in cancer survivors and plays an important role in the regulation of body composition. The purpose of the present study was to determine the specific role of IL-6 in cyclophosphamide-doxorubicin-5-fluorouracil (CAF)-induced changes in fatigue, food intake, and body composition using mice lacking IL-6. Female wild-type (WT) and IL-6− /− mice were injected with four cycles of CAF or normal saline (NS) administered at 21-day intervals. Daily voluntary wheel-running activity (VWRA), used as a proxy for fatigue, and food intake were monitored daily up to 21 days after the fourth dose. Dual-energy X-ray absorptiometry (DEXA) was used to assess treatment-related changes in lean body mass (LBM), fat mass (FM), and bone mineral content (BMC). Patterns of change in fatigue and food intake did not differ between CAF-treated WT and IL-6− /− mice. However, a Genotype × Drug interaction was observed for LBM ( p = 0.047) and FM ( p = 0.035) but not BMC ( p = .569). Whereas WT mice lost LBM and FM during CAF treatment, IL-6-deficient mice did not. Treatment-related decreases in levels of the anabolic hormone insulin-like growth factor-1 (IGF-1) may contribute to LBM and FM loss since CAF decreased IGF-1 levels in an IL-6-dependent manner. These findings implicate IL-6 and possibly IGF-1 in the regulation of body composition in breast cancer patients exposed to cytotoxic chemotherapy.

TNF-α deficiency as protection against sickness behavior related to external beam radiation of the pelvis in mice.

2012 ◽  
Vol 30 (5_suppl) ◽  
pp. 208-208
Author(s):  
Sravana K Chennupati ◽  
Faisal A Siddiqui ◽  
Tasha L. McDonald ◽  
Charles R. Thomas ◽  
Arthur Hung ◽  
...  
Keyword(s):  
Food Intake ◽  
Significant Interaction ◽  
Wheel Running ◽  
Sickness Behavior ◽  
External Beam Radiation ◽  
Beam Radiation ◽  
Running Activity ◽  
Wheel Running Activity ◽  
Tnf Α ◽  
Voluntary Wheel

208 Background: Prostate cancer patients undergoing localized external beam radiation therapy (EBRT), experience significant fatigue during treatment, which can affect physical functioning and QOL. We hypothesize that cancer treatment related fatigue (CTRF) is the same as sickness behavior caused, in part, by increases in TNF-α. Our previous data demonstrate that pelvic EBRT induces systemic increases in TNF-α and a decline in voluntary wheel running activity (VWRA) , an objective measure of sickness in mice. A specific aim of this study was to determine the requirement of EBRT for TNF-α for the induction of sickness behavior. Methods: Daily VWRA was monitored in male WT (n=10) and TNF-α−/− (n=10) anesthetized mice undergoing pelvic EBRT at 4.6 Gy/fraction, 5 days per week for 15 fractions for a total dose of 69 Gy [4.6 X 15 = 69, not 70]. Control WT (n=10) and TNF-α−/− (n= 10) mice underwent anesthesia followed by sham EBRT. The effect of treatment on weight and food intake was also determined by calculating change in weight and daily food intake during treatment. A 2 x 2 repeated measure analysis of covariance ANCOVA was used to determine whether there was a significant interaction between treatment group (EBRT or Control) and genotype (WT or TNF-α−/−) on voluntary wheel running activity controlling for baseline differences in this variable. Similarly a 2 x 2 ANOVA was used to determine whether there was a drug x genotype interaction between change in body weight or food intake. Results: There was a significant effect of EBRT on VWRA (p< 0.001), food intake (p0.002), and weight (p<0.001). We did not however observe a significant interaction between EBRT and genotype in VWRA (p= 0.756), food intake (p=0.654), or weight (p= 0.450). Conclusions: Targeting TNF-α using specific cytokine blocking agents has been suggested as a potential strategy for preventing or managing EBRT related fatigue. Although our prior data support that localized EBRT to the pelvis may induce TNF-α and sickness behavior in mice, our latest data do not support a direct role for this cytokine in mediating these effects.

Exercise Dependence and Morphine Addiction: Evidence From Animal Models

2008 ◽  
Vol 2 (1) ◽  
pp. 17-24 ◽  
Author(s):  
Anthony Ferreira ◽  
Fabien Cornilleau ◽  
Fernando Perez-Diaz ◽  
Charles Cohen-Salmon
Keyword(s):  
Physical Activity ◽  
Animal Models ◽  
Wheel Running ◽  
Activity Wheel ◽  
Morphine Dependence ◽  
Free Access ◽  
Running Activity ◽  
Behavioral Interaction ◽  
Wheel Running Activity ◽  
Morphine Addiction

This study used animal models to examine potential similarities between dependence on physical activity (i.e., exercise) and dependence on morphine. Using C57BL/6 mice, the study also tested the hypothesis that physical exercise (e.g., long-term wheel running) may enhance vulnerability to the development of morphine dependence. The existence of an endorphin-related dependence induced by physical activity was also assessed. Naloxone was used to precipitate morphine withdrawal in mice accustomed to morphine. Specifically, the study sought to assess the intensity of addiction provoked by injection of morphine in mice that engaged in wheel-running activity as opposed to inactive mice. After 25 days of free access to activity wheel, mice that engaged in wheel-running demonstrated increased vulnerability to naloxone-induced withdrawal symptoms, which may be linked to activation of peripheral, as opposed to central, opioid receptors. These results indicate a behavioral interaction in which engaging in wheel running appears to potentiate the effects of morphine addiction. Implications of these findings for understanding human behavior and exercise addiction are also discussed.

Artificial selection for increased wheel-running activity in house mice results in decreased body mass at maturity

1999 ◽  
Vol 202 (18) ◽  
pp. 2513-2520 ◽  
Author(s):  
J.G. Swallow ◽  
P. Koteja ◽  
P.A. Carter ◽  
T. Garland
Keyword(s):  
Genetic Correlation ◽  
Body Mass ◽  
Artificial Selection ◽  
Wheel Running ◽  
House Mice ◽  
Selected Lines ◽  
Voluntary Wheel Running ◽  
Running Activity ◽  
Wheel Running Activity ◽  
Voluntary Wheel

To test the hypothesis that body size and activity levels are negatively genetically correlated, we conducted an artificial selection experiment for increased voluntary wheel-running activity in house mice (Mus domesticus). Here, we compare body masses of mice from control and selected lines after 14 generations of selection. In both groups, beginning at weaning and then for 8 weeks, we housed half of the individuals with access to running wheels that were free to rotate and the other half with wheels that were locked to prevent rotation. Mice from selected lines were more active than controls at weaning (21 days) and across the experiment (total revolutions during last week: females 2.5-fold higher, males 2.1-fold higher). At weaning, mice from selected and control lines did not differ significantly in body mass. At 79 days of age, mice from selected lines weighed 13.6 % less than mice from control lines, whereas mice with access to free wheels weighed 4.5 % less than ‘sedentary’ individuals; both effects were statistically significant and additive. Within the free-wheel-access group, individual variation in body mass of males was negatively correlated with amount of wheel-running during the last week (P&lt;0.01); for females, the relationship was also negative but not statistically significant (P&gt;0.40). The narrow-sense genetic correlation between wheel-running and body mass after 8 weeks of wheel access was estimated to be −0. 50. A negative genetic correlation could account for the negative relationship between voluntary wheel-running and body mass that has been reported across 13 species of muroid rodents.

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