Effects Of Food Restriction Research Articles

Catch-up growth following food restriction exacerbates adulthood glucose intolerance in pigs exposed to intrauterine undernutrition

ObjectiveThe aim of this study was to evaluate the effects of food restriction followed by controlled refeeding on glucose tolerance in pigs exposed to intrauterine malnutrition. MethodsPregnant sows (n = 11) were assigned to either a control (C) group or an undernutrition (U) group (75% of C) during gestation. At postnatal 68 d, the offspring (n = 16) were placed on either a cafeteria feeding (CF) group or a food-restricted (FR) group (75% of CF) for 6 wk. After that, all offspring were fed ad libitum until 189 d (dpn189). ResultsThe results showed that maternal malnutrition induced offspring glucose intolerance, which was demonstrated by increased serum glucose and triacylglycerol content at dpn189, as well as increased area under the blood glucose curve (AUC) during the intravenous glucose tolerance test (i.v.GTT) (P < 0.05). Interestingly, food restriction followed by controlled refeeding further increased serum glucose content at dpn189 and AUC during i.v.GTT in pigs born from U sows (P < 0.05), which was accompanied by catch-up growth during the refeeding period. These changes were associated with increased mRNA levels of hepatic gluconeogenesis (PC, PEPCK) enzymes (P < 0.05), decreased mRNA level of muscle glucose transporter (GLUT4; P = 0.07), and reduced mRNA level of insulin signaling protein (IRS1, P < 0.05) in the liver. ConclusionsOur results indicate that catch-up growth following food restriction can exacerbate glucose intolerance in offspring exposed to intrauterine malnutrition. This may be caused by increased hepatic gluconeogenesis, decreased muscle glucose transport, and impaired hepatic insulin signaling.

Relationships between variable time, percentage of food restriction and liver histology: which alternative is the best for non-alcoholic fatty liver disease (NAFLD) prevention?

The objective of this study was to analyse the hepatic effects of food restriction in an experimental rabbit model. The study comprised 105 rabbits divided into 6 groups. The two control groups were fed ad libitum (ADL) during the entire experiment (C1 and C2). The experimental groups were restricted between 42-49 days of age, where the rabbits received 50g (R1) or 65g (R2) of food per rabbit per day. Others were restricted between 35-42 days of age, where the rabbits received 50g (R3) or 65g (R4) of food per rabbit per day. For liver analysis, 5 rabbits per group were slaughtered at the ages of 49, 56, 63, 70 days from the R1, R2 groups and at 42, 49, 70 days from the R3, R4 groups. All animals from the C1 and C2 groups developed steatosis with inflammation. Animals from the R1 and R2 groups developed steatosis without inflammation while in the R3 and R4 groups steatosis was not visible. In C1 and C2 groups we observed mostly fatty deposit accumulations while in the R1, R2, R3 and R4 groups, more PAS-positive material accumulations were visible. Liver steatosis correlated with inflammation development and interstitial tissue growth. These results can be used in clinical praxis as signs of NAFLD progression. Early food restriction had intense effects on liver morphology and it seems promising that similar approaches could be applied as preventive treatment for NAFLD development.

Nutritional and Protein Deficiencies in the Short Term following Both Gastric Bypass and Gastric Banding.

BackgroundThe number of morbidly obese patients undergoing bariatric surgery (BS) has increased dramatically in recent years. Therefore, monitoring food intake and its consequences in terms of nutritional status is necessary to prevent nutritional deficiencies. The aim of this study was to analyze the effect of food restriction on nutritional parameters in the short-term (≤3 months) period after BS in morbid obesity.MethodIn a prospective study, we followed 22 obese women who underwent Roux-en-Y gastric bypass (GBP) or adjustable gastric banding (AGB) at baseline (T0) and 1 (T1) and 3 (T3) months after surgery. We evaluated food intake, nutrient adequacy and serum concentrations of vitamins and minerals known to be at risk for deficiency following BS.ResultsBefore surgery, we observed suboptimal food intakes, leading to a risk of micronutrient deficiencies. Serum analysis confirmed nutritional deficiencies for iron and thiamine for 27 and 23% of the patients, respectively. The drastic energy and food reduction seen in the short term led to very low probabilities of adequacy for nutrients equivalent across both surgeries. Serum analysis demonstrated a continuous decrease in prealbumin during the follow-up, indicating mild protein depletion in 21 and 57% of GBP patients and 50 and 63% of AGB patients, respectively, at T1 and T3. Regarding vitamins and minerals, systematic supplementation after GBP prevented most nutritional deficiencies. By contrast, AGB patients, for whom there is no systematic supplementation, developed such deficiencies.ConclusionsOur results suggest that cautious monitoring of protein intake after BS is mandatory. Furthermore, AGB patients might also benefit from systematic multivitamin and mineral supplementation at least in the short term.

Food restriction affects circadian and photoperiodic response in black-headed munia (Lonchura malacca malacca)

We determined the effect of food restriction on locomotor activity pattern and gonadal growth on black-headed munia (Lonchura malacca malacca) exposed to12L:12D light–dark cycle. Two groups of male and female munia (n = 5 pairs each) were exposed to 12L:12D (L = 265 lux; D = 0.3 lux) for day 1–7. On day 8, group one received 4 h food (ZT 0–4; ZT 0 = Zeitgeber time, light onset) and group two received food ad libitum (ZT 0–24 h). Locomotor activity pattern and gonadal growth were recorded over the experiment period of one year. Birds were highly active in group one, with a high daily and total activity. However, activity behavior was fully synchronized with light onset in the group two, when food was available ad libitum. Gonadal maturation was initiated in both the groups but the maturation of testis and ovarian follicle was noticed only in group two (food ad libitum). It appears that food restriction affects the locomotor activity and gonadal growth in black-headed munia.

Genotype-dependent lifespan effects in peptone deprived Caenorhabditis elegans.

Dietary restriction appears to act as a general non-genetic mechanism that can robustly prolong lifespan. There have however been reports in many systems of cases where restricted food intake either shortens, or does not affect, lifespan. Here we analyze lifespan and the effect of food restriction via deprived peptone levels on lifespan in wild isolates and introgression lines (ILs) of the nematode Caenorhabditis elegans. These analyses identify genetic variation in lifespan, in the effect of this variation in diet on lifespan and also in the likelihood of maternal, matricidal, hatching. Importantly, in the wild isolates and the ILs, we identify genotypes in which peptone deprivation mediated dietary restriction reduces lifespan. We also identify, in recombinant inbred lines, a locus that affects maternal hatching, a phenotype closely linked to dietary restriction in C. elegans. These results indicate that peptone deprivation mediated dietary restriction affects lifespan in C. elegans in a genotype-dependent manner, reducing lifespan in some genotypes. This may operate by a mechanism similar to dietary restriction.

Food Restriction Prolongs Murine Cardiac Grafts

Overeating and obesity lead to cardiovascular disease, diabetes, and eventually premature death, whereas food or energy restriction reduces risk factors for cardiovascular disease and diabetes and expands the life span. The aim of this study was to investigate the effect of food restriction (FR) in a murine heart transplant model. CBA male recipients (H2k) that underwent transplantation of C57BL/6 (H2b) hearts were assigned to free access group or FR groups with food intake at 60% (40% FR), 50% (50% FR), or 40% (60% FR) of the average food intake for 1 week after transplantation, and each median survival time was measured. We also performed cell proliferation, cytokine production, and flow cytometry assessments. The 60% FR CBA recipients showed prolongation of allograft survival (median survival time, 24 days). Cell proliferation and interferon-γ were suppressed in the 60% FR CBA recipients. Flow cytometry studies showed a lower CD4+CD25+Foxp3+ cell population in splenocytes from the 60% FR CBA recipients. In conclusion, the findings suggest that the prolongation of cardiac allograft resulted from not regulation of alloimmune responses, but partial impairment of alloimmune responses, linking energy restriction to low generation of splenic CD4+CD25+Foxp3+ regulatory T cells.

Food restriction-induced augmentation of heroin seeking in female rats: manipulations of ovarian hormones.

Food restriction augments heroin seeking in chronically food-restricted male rats under withdrawal, an effect not yet examined in female rats. Importantly, women and female rats possess an increased vulnerability to drugs of abuse, which may be mediated by fluctuations in ovarian hormones. We investigated the role of estradiol and progesterone in augmented heroin seeking in chronically food-restricted female rats, under withdrawal. Female rats self-administered heroin for 10-12 days and were then allowed unrestricted (sated) or restricted access to food (FDR; ∼10 % reduction in body weight) for 14 days. On day 14, rats underwent a heroin-seeking test. Exp. 1: Rats underwent ovariectomy or sham surgery and were treated with a low dose of estradiol (5.0 % in cholesterol; subcutaneous capsule). Exp. 2: Rats underwent ovariectomy and were administered with a high dose of estradiol (0.5 mg/kg; subcutaneous) for 8 days before testing. Exp. 3: Progesterone injections (2.0 mg/kg; subcutaneous) were administered 24 h and 2 h before testing. Food restriction resulted in augmented heroin seeking, compared to sated controls. While ovariectomy had no effect, estradiol replacement attenuated the food restriction effect. Injections of progesterone had no effect on heroin seeking in either the sated or FDR groups. The effect of food restriction on heroin seeking in female rats under withdrawal is as robust as previously found in males. Interestingly, estradiol replacement, but not progesterone, attenuates the food restriction effect in the ovariectomized rats, possibly due to its anorexic properties.

Micronutrient and Protein Deficiencies After Gastric Bypass and Sleeve Gastrectomy: a 1-year Follow-up.

Roux-en-Y gastric bypass (GBP) and sleeve gastrectomy (SG) have increased dramatically, potentially increasing the prevalence of nutritional deficiencies. The aim of this study was to analyze the effects of food restriction during the first year after bariatric surgery (BS) on nutritional parameters. Twenty-two and 30 obese patients undergoing GBP and SG were prospectively followed at baseline and 3, 6, and 12 months after BS (N = 14 and N = 19 at T12). We evaluated food intake and nutrient adequacy (T0, T3, T12), as well as serum vitamin and mineral concentration (T0, T3, T6, T12). At baseline, GBP and SG patients had similar clinical characteristics, food intake, nutrient adequacy, and serum concentration. The drastic energy and food reduction led to very low probabilities of adequacy for nutrients similar in both models (T3, T12). Serum analysis demonstrated a continuous decrease in prealbumin during the follow-up, indicating mild protein depletion in 37 and 38% of GBP patients and 57 and 52% of SG patients, respectively, at T3 and T12. Conversely, despite the low probabilities of adequacy observed at T3 and T12, systematic multivitamin and mineral supplementation after GBP and SG prevented most nutritional deficiencies. GBP and SG have comparable effects in terms of energy and food restriction and subsequent risk of micronutrient and protein deficiencies in the first year post BS. Such results advocate for a cautious monitoring of protein intake after GPB and SG and a systematic multivitamin and mineral supplementation in the first year after SG.

Effect of food restriction on energy budget in warm-acclimated striped hamsters

The capacity of small mammals to sustain periods of food shortage largely depends on the adaptive regulation of energy budget in response to the decrease in food supply. In addition to food availability, ambient temperature (Ta) is an important factor affecting the rates of both energy intake and expenditure. To examine the effect of Ta on energy strategy and the capacity to sustain food shortage, striped hamsters were exposed to a warm condition (30°C) and were then restricted to 70% of ad libitum food intake. Body mass, energy intake and expenditure and physiological markers indicative of thermogenesis were measured. Warm exposure had no effect on body mass and digestibility, but decreased energy intake, basal metabolic rate and maximum nonshivering thermogenesis. The mitochondria protein content, cytochrome c oxidase activity and uncoupling protein 1 level of brown adipose tissue were significantly lower in hamsters at 30°C than at 21°C. Food restriction induced a significant decrease in body mass, but the decreased body mass was attenuated at 30°C relative to 21°C. This suggests that striped hamsters could not compensate for the limited food supply by decreasing daily energy expenditure at 21°C, whereas they could at 30°C. The significant reductions in the rates of metabolism and thermogenesis in warm-acclimated hamsters increase the capacity to cope with food shortage. Although, it remains uncertain whether this response represents some generalized evolutionary adaptation, the Ta-dependent adjustment in the capacity to survive food restriction may reflect that warm acclimation plays an important role in adaptive regulation of both physiology and behavior in response to the variations of food availability.

Food availability, energetic constraints and reproductive development in a wild seasonally breeding songbird.

Summary In many organisms, food availability is a proximate cue that synchronizes seasonal development of the reproductive system with optimal environmental conditions. Growth of the gonads and secondary sexual characteristics is orchestrated by the hypothalamic–pituitary–gonadal (HPG) axis. However, our understanding of the physiological mechanisms by which food availability modulates activity of the HPG axis is limited.It is thought that many factors, including energetic status, modulate seasonal reproductive activation. We tested the hypothesis that food availability modulates the activity of the HPG axis in a songbird. Specifically, we food‐restricted captive adult male Abert's Towhees Melozone aberti for 2 or 4 weeks during photoinduced reproductive development. A third group (control) received ad libitum food throughout. We measured multiple aspects of the reproductive system including endocrine activity of all three levels of the HPG axis [i.e. hypothalamic gonadotropin‐releasing hormone‐I (GnRH‐I), plasma luteinizing hormone (LH) and testosterone (T)], and gonad morphology. Furthermore, because gonadotropin‐inhibitory hormone (GnIH) and neuropeptide Y (NPY; a potent orexigenic peptide) potentially integrate information on food availability into seasonal reproductive development, we also measured the brain levels of these peptides.At the hypothalamic level, we detected no effect of food restriction on immunoreactive (ir) GnRH‐I, but the duration of food restriction was inversely related to the size of ir‐GnIH perikarya. Furthermore, the number of ir‐NPY cells was higher in food‐restricted than control birds. Food restriction did not influence photoinduced testicular growth, but decreased plasma LH and T, and width of the cloacal protuberance, an androgen‐sensitive secondary sexual characteristic. Returning birds to ad libitum food availability had no effect on plasma LH or T, but caused the cloacal protuberance to rapidly increase in size to that of ad libitum‐fed birds.Our results support the tenet that food availability modulates photoinduced reproductive activation. However, they also suggest that this modulation is complex and depends upon the level of the HPG axis considered. At the hypothalamic level, our results are consistent with a role for the GnIH and NPY systems in integrating information on energetic status. There also appears to be a role for endocrine function at the anterior pituitary gland and testicular levels in modulating reproductive development in the light of energetic status and independently of testicular growth.

Episodic sucrose intake during food restriction increases synaptic abundance of AMPA receptors in nucleus accumbens and augments intake of sucrose following restoration of ad libitum feeding

Weight-loss dieting often leads to loss of control, rebound weight gain, and is a risk factor for binge pathology. Based on findings that food restriction (FR) upregulates sucrose-induced trafficking of glutamatergic AMPA receptors to the nucleus accumbens (NAc) postsynaptic density (PSD), this study was an initial test of the hypothesis that episodic “breakthrough” intake of forbidden food during dieting interacts with upregulated mechanisms of synaptic plasticity to increase reward-driven feeding. Ad libitum (AL) fed and FR subjects consumed a limited amount of 10% sucrose, or had access to water, every other day for 10 occasions. Beginning three weeks after return of FR rats to AL feeding, when 24-h chow intake and rate of body weight gain had normalized, subjects with a history of sucrose intake during FR consumed more sucrose during a four week intermittent access protocol than the two AL groups and the group that had access to water during FR. In an experiment that substituted noncontingent administration of d-amphetamine for sucrose, FR subjects displayed an enhanced locomotor response during active FR but a blunted response, relative to AL subjects, during recovery from FR. This result suggests that the enduring increase in sucrose consumption is unlikely to be explained by residual enhancing effects of FR on dopamine signaling. In a biochemical experiment which paralleled the sucrose behavioral experiment, rats with a history of sucrose intake during FR displayed increased abundance of pSer845-GluA1, GluA2, and GluA3 in the NAc PSD relative to rats with a history of FR without sucrose access and rats that had been AL throughout, whether they had a history of episodic sucrose intake or not. A history of FR, with or without a history of sucrose intake, was associated with increased abundance of GluA1. A terminal 15-min bout of sucrose intake produced a further increase in pSer845-GluA1 and GluA2 in subjects with a history of sucrose intake during FR. Generally, neither a history of sucrose intake nor a terminal bout of sucrose intake affected AMPA receptor abundance in the NAc PSD of AL subjects. Together, these results are consistent with the hypothesis, but the functional contribution of increased synaptic incorporation of AMPA receptors remains to be established.

Effect of food restriction on the energy metabolism of the Chinese bulbul (Pycnonotus sinensis).

Food resources play an important role in the regulation of animals' physiology and behavior. We investigated the effect of short-term food restriction on metabolic thermogenesis of Chinese bulbuls (Pycnonotus sinensis) by measuring changes in body mass, body fat, basic metabolic rate (BMR), and organ mass of wild-caught Chinese bulbuls from Wenzhou, China. Short-term food restriction induced a significant decrease in body mass and body fat but body mass returned to normal levels soon after food was no longer restricted. Food restriction caused a significant reduction in BMR after 7 days (P<0.05), which returned to normal levels after food restriction ceased. Log total BMR was positively correlated with log body mass (r(2)=0.126, P<0.05). The dry masses of livers and the digestive tract were higher in birds that had been subject to temporary food restriction than in control birds and those subject to continual food restriction (P<0.001 and P<0.05, respectively). There was also significant differences in the dry mass of the lungs (P<0.05), heart (P<0.01), and spleen (P<0.05) in birds subject to short-term food restriction compared to control birds and those subject to continual food restriction. BMR was positively correlated with body and organ (heart, kidney and stomach) mass. These results suggest that the Chinese bulbul adjusts to restricted food availability by utilizing its energy reserves, lowering its BMR and changing the weight of various internal organs so as to balance total energy requirements. These may all be survival strategies that allow birds to cope with unpredictable variation in food abundance.

Increased α1-adrenoreceptor activity is required to sustain blood pressure in female rats under food restriction.

We evaluated the effect of food restriction (FR) on the various reflexes involved in short term cardiovascular regulation; we also evaluated the contribution of the sympathetic nervous systemand of the plasmatic nitric oxide (NO) in the development of the counterregulatory cardiovascular changes triggered by FR. Female rats were subjected to FR for 14 days, and after this period biochemical measurements of biochemical parameters were performed. For physiological tests, animals were anaesthetised, and a catheter was inserted into the femoral artery and vein for the acquisition of blood pressure and heart hate, and drug infusion, respectively.We then tested the Bezold–Jarisch reflex, the baroreflex and chemoreflex and the effect of the infusion of adrenergic receptor antagonists in control and food restricted animals. The rats subjected to severe FR presented biochemical changes characteristic of malnutrition with a great catabolic state. FR also led to hypotension and bradycardia besides reducing the plasmatic concentration of NO. Moreover, activation of the Bezold–Jarisch reflex induced a more pronounced hypotensive response in animals subjected to FR. Intravenous infusion of a α1-adrenoreceptor antagonist induced a greater hypotensive response and a more pronounced tachycardic response in animals under food restriction,while the infusion of β-adrenoreceptor antagonist induced lower increases in blood pressure in these animals. Our results suggest that an increased α1-adrenoreceptor activity in the resistance arteries coupled with a reduction of plasmatic NO contributes in a complementary manner to maintain the blood pressure levels in animals under FR.

Abstract W P250: Food Restriction Ameliorates Neuroinflammation and Provides Protection in a Mouse Model of Ischemic Stroke

Background and Purpose: Neuroinflammation contributes significantly to the progress of ischemic stroke. Recent research suggests that food restriction could reduce inflammatory responses under some pathological conditions. In this study, we demonstrate that food restriction attenuates both grey matter and white matter damage after cerebral ischemia. Methods: Adult male C57BL/6 mice were fed ad libitum (AL) or fed with restricted food (RF; 30% reduction) for 28 days, and then subjected to MCAO or sham operation. Neuronal tissue atrophy and white matter injury were assessed by quantifying the expression of microtubule-associated protein (MAP2) and myelin basic protein (MBP), respectively. Cerebral inflammation was evaluated by immunohistochemical staining of astrocyte and microglia in the ischemic brain. The expression of M1 and M2 markers were further examined to characterize phenotypic changes in brain microglia. Results: RF promotes functional recovery up to 28 days after stroke, as revealed by marketly improved performance in food fault test, cylinder test and Morris water maze test. RF mice exhibited significantly reduced neuronal tissue loss (AL, 19.43±2.40mm3; RF, 10.60±1.74mm3; P &lt; 0.05;n=6/group) and white matter injury (Al,, 0.36±0.08; RF, 0.97±0.07; P &lt; 0.05;n=5/group) as compared to AL mice at 28 days after ischemia. Meanwhile, we observed suppressed astrocyte (LF, 3.22±0.26mm2; RF, 2.30±0.19mm2; P &lt; 0.05;n=5/group) and microglia (P &lt; 0.05;n=5/group) activation in RF mice. Furthermore, food restriction increased the percentage of M2 phenotype and reduced the percentage of M1 phenotype in activated microglia (P &lt; 0.05;n=5/group). Conclusions: Taken together, food restriction can promote functional recovery. These protective effects might be partially attributed to the effect of food restriction in alleviating neuroinflammation and directing beneficial microglial response after stroke. Our study suggests that food restriction is an effective non-pharmacological approach to promote long-term post-stroke recovery.

Interrelationship between feeding level and the metabolic hormones leptin, ghrelin and obestatin in control of chicken egg laying and release of ovarian hormones

The aim of the present experiment is to examine the role of nutritional status, metabolic hormones and their interrelationships in the control of chicken ovarian ovulatory and secretory activity. For this purpose, we identified the effect of food restriction, administration of leptin, ghrelin 1-18, obestatin and combinations of food restriction with these hormones for 3days on chicken ovulation (egg laying) rate and ovarian hormone release. The release of progesterone (P), testosterone (T), estradiol (E) and arginine-vasotocin (AVT) by isolated and cultured ovarian fragments was determined by EIA. It was observed that food restriction significantly reduced the egg-laying rate, T, E and AVT release and promoted P output by ovarian fragments. Leptin, administrated to ad libitum–fed chickens, did not change these parameters besides promoting E release. Nevertheless, administration of leptin was able to prevent the effect of food restriction on ovulation, T and E (but not P or AVT) release. Ghrelin 1-18 administration to ad libitum–fed birds did not affect the measured parameters besides a reduction in P release. Ghrelin 1-18 administration prevented the food restriction–induced decrease in ovarian T, E and AVT, but it did not change P output or egg laying. Obestatin administrated to control chicken promoted their ovarian P, E and inhibited ovarian AVT release but did not affect egg laying. It was able to promote the effect of food restriction on P, T and AVT, but not E release or egg laying. Our results (1) confirm an inhibitory effect of food restriction on chicken ovulation rate; (2) shows that food restriction–induced reduction in egg laying is associated with a decrease in ovarian T, E and AVT and an increase in ovarian P release; (3) confirm the involvement of metabolic hormones leptin, ghrelin and obestatin in the control of chicken ovarian hormones output; and (4) the ability of metabolic hormones to mimic/antagonize or prevent/promote the effects of food restriction on both egg laying and ovarian hormones demonstrates that nutritional status can influence ovarian ovulatory and endocrine functions via changes in metabolic hormones.

A 1-night operant learning task without food-restriction differentiates among mouse strains in an automated home-cage environment

Individuals are able to change their behavior based on its consequences, a process involving instrumental learning. Studying instrumental learning in mice can provide new insights in this elementary aspect of cognition. Conventional appetitive operant learning tasks that facilitate the study of this form of learning in mice, as well as more complex operant paradigms, require labor-intensive handling and food deprivation to motivate the animals. Here, we describe a 1-night operant learning protocol that exploits the advantages of automated home-cage testing and circumvents the interfering effects of food restriction. The task builds on behavior that is part of the spontaneous exploratory repertoire during the days before the task. We compared the behavior of C57BL/6J, BALB/cJ and DBA/2J mice and found various differences in behavior during this task, but no differences in learning curves. BALB/cJ mice showed the largest instrumental learning response, providing a superior dynamic range and statistical power to study instrumental learning by using this protocol. Insights gained with this home-cage-based learning protocol without food restriction will be valuable for the development of other, more complex, cognitive tasks in automated home-cages.

Effects on Fat Distribution by Food Restriction in Zucker Diabetic Fatty Rats

Aim: Zucker diabetic fatty (ZDF) rat is a type 2 diabetic model with hyperphagia, obesity, and the overt fat storage. The present study investigated effects of food restriction for 15 weeks on the fat distribution in ZDF rats. Methods: ZDF rats were pair-fed with Zucker Lean (ZL) rats from 9 to 24 weeks of age. Body weight and blood chemistry parameters, such as glucose, insulin, triglyceride, total cholesterol and non-esterified fatty acid, were measured every two weeks. The visceral and subcutaneous fat weights were measured at 24 weeks of age by computed tomography (CT) analysis, and the total fat weight and the ratio of visceral fat weight to subcutaneous fat weight (V/S ratio) were determined. Results: The ZDF rats showed obesity, hyperglycemia, hyperinsulinemia, and hyperlipidemia as compared with the ZL rats. Pair-fed ZDF rats showed a temporary decrease in body weight and a suppression of hyperglycemia, but the blood insulin and lipid levels increased. Total fat weight was about 2.4 times higher in the ZDF rats than the ZL rats. The total fat weight in Pair-fed ZDF rats Short Research Article Ohta et al.; BJMMR, 7(8): 699-704, 2015; Article no.BJMMR.2015.378 700 was increased by 56%, but the V/S ratio was decreased by 38% at 24 weeks of age. Conclusion: The change of fat distribution by dietary restriction may be related to the improvement of glucose and lipid metabolic disorders in diabetes mellitus with obesity.

食物限制对黑线仓鼠免疫功能的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 食物限制对黑线仓鼠免疫功能的影响 DOI: 10.5846/stxb201305241171 作者: 作者单位: 曲阜师范大学生命科学学院,曲阜师范大学 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金(31070332,31370427);山东省自然科学基金(ZR2013CM019);曲阜师范大学博士启动基金(bsqd20100204) Effect of food restriction on immune function in the striped hamster (Cricetulus barabensis) Author: Affiliation: College of Life Sciences,Qufu Normal University,Qufu,273165,Shandong Province Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:温带地区小型哺乳动物经常面临着食物资源的波动。食物对动物的免疫功能具有重要影响。将19只成年雄性黑线仓鼠(Cricetulus barabensis)随机分为自由取食组(n=9)和限食组(n=10)。注射植物血球凝集素(PHA)来测定细胞介导的免疫反应,用匙孔血蓝蛋白(KLH)免疫动物,然后测定抗KLH抗体的浓度以反映其体液免疫功能。旨在检验食物限制是否会抑制黑线仓鼠的细胞免疫和体液免疫功能。结果发现,与对照组相比,限食组黑线仓鼠具有较低的体重、体脂、脾脏鲜重、血清瘦素水平、免疫球蛋白IgG和IgM浓度。而限食对胸腺鲜重、白细胞数、皮质酮水平以及PHA反应没有显著影响。结果表明黑线仓鼠免疫系统的不同成分对限食反应存在差异,在食物资源短缺时,黑线仓鼠防御细胞外病原体的能力降低,从而导致生存能力的下降。 Abstract:The immune system protects animals against environmental pathogens, and hence it plays an important role in their survival and fitness. However, immune function is influenced by many factors including food availability. Small mammals in the temperate zone often face fluctuations in food availability, which is important to their survival. Changes in food availability may have a great influence on an animals' immunity. Some investigators have examined the effect of reduced food availability (i.e., food restriction) on the immune function in small rodents, but their results are often inconsistent. Food restriction could depress, enhance or have no effect on immunity in different species. In order to clarify the discrepancy between results, the striped hamster (Cricetulus barabensis) was used to examine the effect of food restriction on its immune function. The striped hamster is a major pest rodent in northern China. It is granivorous, nocturnal and feeds mainly on plant stems and leaves during summer and forages crop seeds in winter. The climate is arid and characterized by warm and dry summers and cold winters. Thus, the species experiences great seasonal fluctuations in temperature, photoperiod as well as food quality and availability. The question we focused on in the present study was how the immune function would vary in the face of reduced food availability for hamsters. Nineteen adult male hamsters were randomly divided into the fed ad libitum group (Fed, n=9) and food restricted group (FR, n=10) (90% of baseline food intake). The course of food restriction was 21 days. Hamsters were injected with phytohaemagglutinin (PHA) and keyhole limpet haemocyanin (KLH) solution to assess cellular and humoral immunity, respectively. Our goal was to test whether food restriction would suppress cellular and humoral immunity in striped hamsters. Body mass in the FR group decreased significantly after 21 days of food restriction, whereas body mass in the Fed group did not change significantly. Body mass in the FR group was significantly lower than that of the Fed group after 10 days of food restriction. Food restriction significantly reduced perirenal fat, perirenal fat content, retroperitoneal fat, total body fat, and wet spleen mass in the FR group compared with the Fed group. However, it had no significant effect on the wet thymus mass or white blood cells. Immunoglobulin (Ig) G and IgM concentrations were reduced significantly in the food restricted hamsters in contrast with the Fed control group, which indicated the suppressive role of food restriction on humoral immunity. PHA response did not differ between the two groups, suggesting cellular immunity was not influenced by food restriction. Food restricted hamsters had significantly lower serum leptin levels than that of the control group, while corticosterone levels were not affected by food restriction. Taken together, our results suggest that different components of the immune system respond differently to food restriction in striped hamsters. Humoral immunity was suppressed in food restricted hamsters, which might be due to their lower body fat mass and lower leptin levels. In the face of food shortage, striped hamsters might be more prone to extracellular pathogens and their survival capability would decrease. 参考文献 相似文献 引证文献

Food restriction beginning at lactation interferes with the cellular dynamics of the mucosa and colonic myenteric innervation in adult rats.

The effects of food restriction (FR) on the morphoquantitative aspects of the wall and myenteric neurons of the proximal colon in adult rats were analysed. FR was imposed by duplication of the experimental brood size in relation to the control brood during lactation. The FR group received a 50% reduction of food from weaning until 90 days of age. Samples of the colon underwent histological processing to morphometrically analyze the crypts, muscularis mucosae, tunica mucosa, and muscularis externa. We determined the number of goblet cells and serotoninergic enteroendocrine cells, and morphoquantitatively studied the myenteric neuronal population. FR caused hypertrophy in the tunica mucosa, increase in crypt depth and in the muscular layer of the mucosa, a decrease in the thickness of the tunica muscularis and in the number of goblet cells and an increase in serotoninergic cells. A higher neuronal density in the ganglia and a reduction of the cell profile area were observed in the FR group. FR imposed since lactation led to hypertrophy of the tunica mucosa, a reduction of neutral mucin production, atrophy of the tunica muscularis, and an increase in the survival neuronal in adult rats, attributable to an increase in the number of serotoninergic enteroendocrine cells in mucosa.

Effect of food restriction on energy intake and thermogenesis in Yunnan red-backed vole (Eothenomys miletus) with different metabolic levels

Shortage of food resources has significant effects on many physiological parameters of animals. The aim of the present study was to examine the relationship between the energetics countermeasures in response to food restriction and the levels of metabolism in Eothenomy miletus. Survival rate, body mass, basal metabolic rate (BMR), nonshivering thermogenesis (NST), body fat mass, serum leptin levels and other physiological parameters were measured. Animals were divided into high-BMR (hBMR) and low-BMR (lBMR) group. The two groups were restricted to 70% of ad libitum food intake for 4 weeks. The data showed that food intake increased by 24.5% in hBMR group than that in lBMR group before the experiment. Body mass, body fat mass, BMR and NST with hBMR or lBMR group significantly decreased after food restricting. Eighty percent of E. miletus survived with hBMR group, but 60% of E. miletus survived with lBMR group. Serum leptin levels were positively correlated with body mass, BMR and NST. The results suggested that E. miletus could apply physiological adjustments to adapt the period of food shortage by reducing energy metabolism, providing the support for the “metabolism switch hypothesis”. E. miletus with hBMR had decreased energy expenditure to maintain the normal physiological function. However, lBMR group could not decrease energy expenditure to meet the stress of available energy resource, which led to body mass decreased and mortality rate increased. Serum leptin levels may be involved in the regulation of energy balance and body mass in E. miletus during the food restriction.