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PubMed1995

Effect of early nutrient restriction on broiler chickens. 1. Performance and development of the gastrointestinal tract.

An experiment was conducted to determine the effects of early nutrient restriction on performance and development of the gastrointestinal tract of broiler chickens. Four hundred male broiler (Ross x Ross) chicks raised in floor pens were assigned to two treatment groups. One group was given ad libitum access to feed from 1 to 48 d of age. The second group was feed restricted from 7 to 14 d of age to an energy intake of 1.5 x BW.67 kcal ME/d and then given ad libitum access to feed from 14 to 48 d. Body weight and feed intake were determined weekly. At 49 d of age, birds were processed for carcass yield, abdominal fat pad measurement, and body composition analysis. Broilers were also sampled at 7, 14, 21, and 41 d of age for proventriculus, gizzard, small intestine (duodenum, jejunum, and ileum), pancreas, and liver weights and for intestinal length measurements. Total DNA, protein:DNA, and RNA:DNA ratios of livers and jejuna were determined as indexes of changes in cell size and number. Feed-restricted broilers failed to catch up to the Control birds in BW at 48 d of age but were superior (P < .01) in overall feed efficiency. No treatment effects were observed on breast meat yields or abdominal fat. Moreover, percentage carcass fat, crude protein, ash, and dry matter were not affected by restricted feeding. Body weight and weights of gastrointestinal organs were reduced (P < .01) by feed restriction at 14 d of age. Restricted feeding, however, did not decrease the relative weights of organs, except for liver. Feed restriction also resulted in a reduction (P < .01) of liver cell number and size and a decrease in jejunum cell number. All organs recovered normal weight on refeeding, and all cellular constituent ratios (e.g., RNA:DNA, RNA:protein, and protein:DNA) returned to normal by 41 d of age. Absolute and relative weights of supply organs (e.g., proventriculus, gizzard, small intestine, liver, and pancreas) were less affected by feed restriction and responded more quickly to refeeding than the whole body.

Animal Nutritional Physiological Phenomena↗

PubMed1995

The effect of early feed restriction on broiler performance.

In an attempt to determine the effect of early feed restriction on broiler performance, nine trials were conducted. Feed restriction was based on previous 24-h feed consumption values of the full-fed control groups. Feed restriction was from either 7 to 14 d of age (Trials 1 to 5) or 8 to 16 d of age (Trials 6 to 9). The treatments for Trials 1 to 5 were 90, 75, and 60% of previous 24-h feed consumption of full-fed controls. The treatments for Trials 6 to 9 were 80 and 60% of previous 24-h feed consumption of full-fed controls. Early feed restriction did not affect abdominal fat. Early feed restriction did improve feed conversion (grams of feed:BW). Males and females equated at 41 d of age for an 8% reduction (90% feed restriction) at 14 d of age when compared with full-fed control broilers. Neither females or males could overcome a 17 or 18% weight reduction (75% feed restriction) at 14 d of age by 41 d of age. At 48 or 49 d of age, both males and females could equate in weight with full-fed control broilers for a weight reduction of 27 and 31% (60% feed restriction) at 16 d of age. Mortality or deformed legs did not differ between any of the comparisons.

Animals↗

PubMed2005

Treatment of benign paroxysmal positional vertigo: necessity of postmaneuver patient restrictions.

Benign paroxysmal positional vertigo (BPPV) is the most common cause of vertigo, resulting from migration of otoconia into the semicircular canals. Several treatment methods involving positioning maneuvers that return the otoconia to the utricle have been described. Following treatment, most patients are provided with a variety of activity restrictions. Previous studies suggest that, overall, BPPV treatment may be successful without these restrictions. The purpose of this study was to determine the necessity of postmaneuver restrictions using an experimental and control group with participants matched for age, gender, involved ear, and symptoms. A canalith repositioning maneuver was used to treat the BPPV. During postmaneuver instruction, the 21 participants assigned to the restricted group were provided with typical activity restrictions. Twenty-one participants assigned to the nonrestricted group were given no postmaneuver restrictions. Only one participant in the restricted group and two participants in the nonrestricted group were not clear at the one-week follow-up appointment. Results indicated that postmaneuver restrictions do not improve treatment efficacy.

Adult↗

PubMed2005

The human CD1-restricted T cell repertoire is limited to cross-reactive antigens: implications for host responses against immunologically related pathogens.

The repertoires of CD1- and MHC-restricted T cells are complementary, permitting the immune recognition of both lipid and peptide Ags, respectively. To compare the breadth of the CD1-restricted and MHC-restricted T cell repertoires, we evaluated T cell responses against lipid and peptide Ags of mycobacteria in leprosy, comparing tuberculoid patients, who are able to restrict the pathogen, and lepromatous patients, who have disseminated infection. The striking finding was that in lepromatous leprosy, T cells did not efficiently recognize lipid Ags from the leprosy pathogen, Mycobacterium leprae, or the related species, Mycobacterium tuberculosis, yet were able to efficiently recognize peptide Ags from M. tuberculosis, but not M. leprae. To identify a mechanism for T cell unresponsiveness against mycobacterial lipid Ags in lepromatous patients, we used T cell clones to probe the species specificity of the Ags recognized. We found that the majority of M. leprae-reactive CD1-restricted T cell clones (92%) were cross-reactive for multiple mycobacterial species, whereas the majority of M. leprae-reactive MHC-restricted T cells were species specific (66%), with a limited number of T cell clones cross-reactive (34%) with M. tuberculosis. In comparison with the MHC class II-restricted T cell repertoire, the CD1-restricted T cell repertoire is limited to recognition of cross-reactive Ags, imparting a distinct role in the host response to immunologically related pathogens.

Adult↗

PubMed2001

Weight gain with risperidone among patients with mental retardation: effect of calorie restriction.

BACKGROUND: The atypical antipsychotics cause weight gain, which is poorly understood in terms of its mechanism and treatment. A usual recommendation for treatment of antipsychotic-induced weight gain includes calorie restriction and exercise. The authors describe their recent clinical experience with calorie restriction in adults with mental retardation treated with risperidone. METHOD: A retrospective chart review was performed on the records of 50 adult patients with mental retardation treated with risperidone while residing at a habilitation center. We assessed dose and duration of risperidone treatment, weight, changes in calorie intake, and frequency of aggressive behavior. RESULTS: Of the 50 patients, 39 had adequate data for analysis. Thirty-seven of the 39 patients gained weight with a mean of 18.8 lb (8.3 kg) over about 2 years. Twenty of the 37 patients were calorie restricted. Three of the 20 calorie-restricted patients lost weight at a rate of 0.2 lb (0.1 kg) per month. The other 17 calorie-restricted patients and the 17 patients who were not calorie restricted continued to gain weight at a rate of 0.8 lb (0.4 kg) per month over about another 2 years of treatment. The amount of weight gain was not dose related. Calorie restriction led to no deterioration in behavior. CONCLUSION: The current investigation lends support to data that note weight gain with risperidone in adults with mental retardation. It suggests that calorie restriction does not lead to weight loss or behavioral deterioration and that weight gain is not dose related.

Aggression↗

PubMed1999

Estrogen-induced pituitary tumor development in the ACI rat not inhibited by dietary energy restriction.

We have demonstrated that a 40% restriction of dietary energy consumption virtually abolishes the development of prolactin (PRL)-producing pituitary tumors in Fischer 344 (F344) rats treated chronically with estrogen, apparently by inhibiting the ability of estrogen to enhance survival within a rapidly proliferating lactotroph population. The purpose of the study reported here was to determine whether energy restriction exerts a similar antitumorigenic action in another rat strain, August x Copenhagen-Irish (ACI), in which PRL-producing pituitary tumors develop in response to estrogen treatment. Ovariectomized female ACI rats were either allowed to consume a control diet ad libitum or were fed a modified diet that restricted energy consumption by 40% relative to the amount of energy consumed by animals fed the control diet. We also examined the ability of 17beta-estradiol (E2) administered for 20 wk via subcutaneous Silastic implants to induce development of PRL-producing pituitary tumors. Treatment with E2 increased pituitary weight as well as the pituitary weight-to-body weight ratio and induced gross hyperprolactinemia to the same extent in ACI rats fed either the control or the energy-restricted diet. Moreover, dietary energy restriction did not affect the ability of E2 to induce pituitary cell proliferation or inhibit apoptosis, as evidenced by quantification of two surrogate markers. These data provide compelling evidence that a 40% restriction of energy consumption does not inhibit the ability of E2 to induce pituitary tumor development in the ACI rat. In conjunction with our published studies of the F344 rat strain, the data presented herein indicate that the inhibitory effects of dietary energy restriction on estrogen-induced pituitary tumor development are rat-strain specific and suggest that sensitivity to specific antitumorigenic actions of energy restriction is strongly affected by genetic background.

Animals↗

PubMed1999

The effects of age and dietary restriction without nutritional supplementation on whole bone structural properties in C57BL/6J mice.

While caloric restriction is a proven means to extend longevity, its effects on bone are not well understood. This study examined the effects of dietary restriction without vitamin or mineral supplementation on bone in female 60- and 120-day-old C57BL/6J mice. Baseline controls were sacrificed at 60 or 120 days, while diet-restricted animals ate approximately 72.9-78.6% of the ad libitum fed animals for thirty days. 60-day-old ad libitum animals experienced normal growth with average increases of 6.4% in bone length, 23.5% in bone mass, 9.4% in %mineralization, 36.4% in maximum strength, 59.2% in stiffness, 22.3% in cortical thickness, 12.9% in %cortical area, and 11.3% in microhardness. Growth in 120-day-old ad libitum animals followed a trend but with more modest increases. Diet-restricted mice matured very little from baseline levels in 60-day-old animals. There were no significant changes from baseline levels in the parameters indicated above, except for a 8.3% decrease in %cortical area attributable to increased resorption. 120-day-old diet-restricted animals also evidenced little deviation from baseline levels except for significant decreases in %mineralization (2.1%) and %cortical area (6.7%). The effects of diet restriction on bone properties decreased with age. Bone from 60-day-old diet-restricted mice showed diminished mechanical and compositional properties, resulting from little growth and excess resorption. Bone from 120-day-old diet-restricted mice showed little growth and some resorption. Increased resorption, localized on the endosteal surfaces, likely minimized the negative impact of structural degradation of the long bones. Resorption may have also provided minerals to compensate for nutritional deficiencies.

Aging↗

PubMed2001

Energy expenditure of rats subjected to long-term food restriction.

Food restriction, even when expressed per unit of metabolic mass, leads to energy conservation as seen by decreased oxygen consumption. The objective of the present study was to verify whether the energy conservation mechanism reduces energy expenditure for as long as food restriction lasts or whether a return to basal level may occur without realimentation, mainly in mildly food-restricted rats. Wistar rats were brought to the laboratory on weaning. They were then assigned to control group that received ad libitum food intake, R10 and R20 groups that received 90 and 80%, respectively, of the food eaten by control group and RM group that received an amount of food enough only to keep body weight. The food restriction period lasted for 3 months and was followed by another month during which all groups received ad libitum food intake. The results showed that even in animals subjected to mild food restriction (10%) there was a sustained decrease in oxygen consumption that lasted until refeeding of the animals. The results led to the conclusion that the energy conservation mechanism is active from little food restriction until more stronger levels of restriction, in a proportional manner, and the decreased energy expenditure is maintained during the whole food restriction period.

Analysis of Variance↗

PubMed2002

Identification of HLA DR7-restricted epitopes from human telomerase reverse transcriptase recognized by CD4+ T-helper cells.

CD4+ T cells play critical roles in initiating, regulating, and maintaining antitumor immune responses. One way to improve current tumor vaccines that mainly induce CTLs would be to activate antigen-specific CD4+ T cells that recognize MHC class II restricted tumor associated antigens. Human telomerase reverse transcriptase (hTRT) is preferentially expressed by various tumors and, therefore, could be a universal tumor antigen. In this study, we used a combined approach of using the prediction software TEPITOPE to select class II epitope candidates and in vitro T-cell biological analysis to identify class II-restricted epitope(s) in hTRT. We first identified several HLA-DR7-restricted class-II epitope candidates in hTRT by examining human T-cell responses to synthetic peptides. We then characterized these HLA-DR7-restricted hTRT epitope candidates by establishing and analyzing peptide-specific T-cell clones. It was demonstrated that CD4+ T cells specific for the HLA-DR7-restricted hTRT(672) epitope (RPGLLGASVLGLDDI) can respond to naturally processed hTRT proteins. Furthermore, the hTRT(672)-specific T cells recognized hTRT antigen from various tumors, including prostate cancer, breast cancer, melanoma, and leukemia. Thus, the identification of the naturally processed HLA-DR7-restricted hTRT epitope, together with the previous finding of class I-restricted hTRT epitopes, provide a basis for the combined application of class I- and II-restricted hTRT epitopes to induce potent, long-term CD4+ and CD8+ T-cell responses against a broad spectrum of tumors.

Amino Acid Sequence↗

PubMed2003

Induction of caspase-dependent and -independent apoptosis in response to methionine restriction.

Tumor cells are more sensitive to methionine restriction than normal tissues, a phenomenon known as methionine auxotrophy. Previous studies have demonstrated that methionine restriction causes tumor cell growth arrest and eventually apoptosis. The current studies were undertaken to elucidate the molecular pathways leading to apoptosis induced by methionine restriction. We found that methionine restriction induced formation of oligonucleosomal DNA fragment and cytochrome c release from mitochondria in methionine-dependent PC3 and Hela cells. Methionine restriction also led to cleavage and activation of initiator and effector caspases in Hela cells but not PC3 cells. Furthermore, methionine restriction resulted in cleavage of BID and reduction in Bcl-2 levels in both cell lines. These data suggest that apoptosis induced by methionine restriction is mitochondria-dependent. Methionine restriction induced caspase-independent cell death in PC3 cells, whereas it stimulated caspase-dependent cell death in Hela cells. Cleavage of BID and decreased expression of Bcl-2 upon methionine deprivation may be the underlying mechanism to stimulate release of cytochrome c from mitochondria.

Adenocarcinoma↗

PubMed1992

Tissue distribution of human minor histocompatibility antigens. Ubiquitous versus restricted tissue distribution indicates heterogeneity among human cytotoxic T lymphocyte-defined non-MHC antigens.

We determined the tissue distribution of 7 human minor histocompatibility (H) Ag. Each of these Ag is defined by one or more MHC class I-restricted CTL clones, previously generated from PBL primed against minor H Ag by HLA-identical bone marrow transplantation (BMT). CTL-mediated lysis of tissue-derived cells and cultured cell lines was used as an in vitro assay for minor H Ag expression of several human tissues. The Ag HA-3 (HLA-A1-restricted), HA-4 (HLA-A2 restricted), HA-6 and HA-7 (HLA-B7 restricted), and the male-specific Ag H-Y (HLA-A2 and B7 restricted) were found to be expressed on cells of all tissues tested. In contrast, the HLA-A2-restricted Ag HA-1 and HA-2 were demonstrated on PHA-blasts, EBV-BLCL, purified T cells, B cells, monocytes, and immature thymocytes, but could not be demonstrated on skin-derived cultured fibroblasts, keratinocytes, melanocytes, cultured epithelial cells of kidney proximal tubili, and umbilical cord vein-derived endothelial cells. Incubation of the latter cell lines with rIFN-gamma, rTNF-alpha, and/or rIL-1 alpha, in concentrations shown to maximally increase their susceptibility to lysis by allo-MHC class I CTL, did not induce recognition by HA-1- and HA-2-specific CTL in vitro. These results indicate an ubiquitous tissue expression of the minor H Ag HA-3, -4, -6, -7 and H-Y in contrast to a to the hemopoietic cell lineage-restricted expression for HA-1 and HA-2. The heterogeneity in tissue expression of T cell-defined, class I-restricted non-MHC Ag implies that they might be derived from intracellular proteins with either an ubiquitous or a more specialized cell type-specific function.

Cytotoxicity, Immunologic↗

PubMed2004

[Importance of conservative treatment and physical load restriction to the course of Osgood-Schlatter's disease].

Osgood- Schlatter's disease is one of most common causes of knee pain in young patients. In 2000-2002, 171 young patients were consulted for Osgood-Schlatter's disease in the Departments of Orthopedics and Traumatology in Kaunas University of Medicine. There were 41 (24%) females and 130 (76%) males; the age ranging from 10 to 27 years. Patients were divided into two groups: the first group (92 patients) underwent conservative treatment and physical load restriction; the second group (79 patients) had no physical load restriction or they neglected reduced physical load guidelines. In the first group 52 patients were treated by conservative measures and physical load restriction, while 40 patients had only physical load restriction. Pain disappeared faster (approximately after 13 months) in the first group patients, who were treated conservatively and had reduced physical load, compared to patients, who had only physical load restriction (pain disappeared approximately after 15 months), p<0.05 (p=0.0008). Pain disappeared faster in patients who had only physical load restriction (approximately after 15 months) compared to the second group patients who had no physical load restriction (approximately after 16.5 months), p<0.05 (p=0.006). There was 1 complication (encapsulated ossification producing pain) in the first group, compared with 8 complications in the second one (2 patients with 3 type avulsion fracture, 1 patient with 2 type avulsion fracture, and 5 patients with encapsulated ossification producing pain). Complications were treated intraoperatively. Physical load restriction is important for beneficial course of Osgood-Schlatter's disease and prevention of complications.

Adolescent↗

PubMed2005

State smoking restrictions for private-sector worksites, restaurants, and bars--United States, 1998 and 2004.

Secondhand smoke is a known carcinogen. Exposure to secondhand smoke causes approximately 35,000 heart disease deaths and 3,000 lung cancer deaths among nonsmokers in the United States every year. Implementing policies that establish smoke-free environments is the most effective approach to reducing secondhand smoke exposure among nonsmokers. Smoking restrictions and smoke-free policies can take the form of laws or regulations implemented at the state or local level or of voluntary policies implemented by private employers and businesses. Smoking restrictions limit smoking to certain areas within a venue; smoke-free policies ban smoking within the entire venue. One of the national health objectives for 2010 is to establish laws in all 50 states and the District of Columbia (DC) that prohibit or restrict smoking in public places and worksites. A related objective calls for all worksites to voluntarily implement policies that prohibit or restrict smoking. To assess progress toward meeting the first objective, CDC reviewed the status of state laws restricting smoking as of December 31, 2004, updating a 1999 study that reported on such laws as of December 31, 1998. This report summarizes the changes in state smoking restrictions for private-sector worksites, restaurants, and bars that occurred during 1999-2004. The findings indicate an increase in the number and restrictiveness of state laws regulating smoking in private-sector worksites, restaurants, and bars from 1999 through 2004. At the end of 2004, however, 16 states still had no restrictions on smoking in any of the three settings considered. Although secondhand smoke exposure among U.S. nonsmokers has decreased sharply in recent years, a substantial portion of nonsmokers continue to be exposed to secondhand smoke.

Restaurants↗

PubMed2005

Changes in antibiotic use, cost and consumption after an antibiotic restriction policy applied by infectious disease specialists.

The study was designed to compare antibiotic use, cost and consumption before and after an initiation of an antibiotic-restriction policy in our hospital. The policy was applied in 2003, and the prescription of two groups of antibiotics (intravenously used and expensive antibiotics) was restricted. A prescription for the restricted antibiotics could be obtained with approval by an infectious disease specialist (IDS). All the hospitalized patients who received antibiotics were evaluated by a cross-sectional study with standard criteria. The annual cost and consumption of antibiotics were evaluated. After restriction, the rate of antibiotic use decreased from 52.7 to 36.7% (P < 0.001), and the appropriate use increased from 55.5 to 66.4% (P < 0.05). Appropriate use was higher for restricted antibiotics (88.4%) than for unrestricted ones (58.2%) (P < 0.001), and higher in the presence of ID consultation (97.5%) than in the absence of consultation (55.7%) (P < 0.001). Culture-based treatment was increased, and appropriate use in such cases (93.0%) was higher than empirical treatment (33.3%) (P < 0.001). After the restriction policy, consumption of antibiotics belonging to the restricted groups was decreased by 44.8%. Total expenditure of all antibiotics was decreased by 18.5%, and the savings were US$332,000 per year. This restriction policy was effective in promoting rational antibiotic prescription and lowering antibiotic cost and consumption in our hospital.

Anti-Bacterial Agents↗

PubMed2006

Tiagabine is associated with sustained attention during sleep restriction: evidence for the value of slow-wave sleep enhancement?

STUDY OBJECTIVES: To evaluate the impact of enhanced slow-wave sleep (SWS) on behavioral, psychological, and physiologic changes resulting from sleep restriction DESIGN: A double-blind, parallel-group, placebo-controlled design was used to compare tiagabine, 8 mg, (a SWS-enhancing drug) to placebo during 4 nights of sleep restriction (time in bed = 5 hours per night). Behavioral, psychological, and physiologic measures of the impact of sleep restriction were compared between groups at baseline, during sleep restriction, and following recovery sleep. SETTING: Two sleep research laboratories. PARTICIPANTS: Thirty-eight healthy adults; 9 men and 10 women (mean age: 26.0 +/- 6.1 years) in the placebo group and 8 men and 11 women (mean age: 26.7 +/- 8.1 years) in the tiagabine 8 mg group INTERVENTIONS: Both experimental groups underwent 4 nights of sleep restriction. Each group received either tiagabine 8 mg or placebo on all sleep-restriction nights, and both groups received placebo on baseline and recovery nights. MEASUREMENTS AND RESULTS: Polysomnography documented a SWS-enhancing effect of tiagabine. The placebo group displayed the predicted deficits due to sleep restriction on the Psychomotor Vigilance Task and the Multiple Sleep Latency Test. Compared with placebo, the tiagabine group did not demonstrate impairment in sustained attention on the Psychomotor Vigilance Test, performed better on the Wisconsin Card Sorting Task, reported more restorative sleep, and had less of an increase in afternoon-evening salivary free cortisol. Multiple Sleep Latency Test, ratings of sleepiness, recovery sleep, and other measures did not differ between groups. CONCLUSIONS: To our knowledge these findings are the first to be consistent with the hypothesis that pharmacologic SWS enhancement reduces selective aspects of the behavioral, psychological, and physiologic impact of sleep restriction.

Adult↗

PubMed1991

Influence of diet and calorie restriction on the initiation and promotion of skin carcinogenesis in the SENCAR mouse model.

Diets were restricted to 60% of the intake of the control mice by feeding less diet (total diet restriction, TDR) or by feeding fewer calories from fat and carbohydrate (calorie restriction, CR) during the initiation or promotion phases of skin tumorigenesis in female SENCAR mice. Skin cancer was initiated by topical treatment with 10 nmol of 7,12-dimethylbenzanthracene in acetone and promoted by twice weekly treatments with 12-O-tetradecanoylphorbol-13-acetate in acetone for 20 wk. Dietary restriction preceding and during 7,12-dimethylbenzanthracene treatment did not influence skin papilloma or carcinoma yield. Papilloma incidence and the number of papillomas per effective mouse were reduced in mice restricted by both TDR and CR protocols during and following promotion with 12-O-tetradecanoylphorbol-13-acetate. Papilloma size was reduced at experimental wk 16 and 20 in both TDR and CR groups fed these diet regimens during promotion. However, by wk 28 and 32, papilloma sizes were similar in the control and TDR groups, and smaller papillomas were observed only in the CR group. The average carcinoma latency was extended by 26% in the groups restricted during promotion, and incidence was reduced in both groups. The reduction, however, was statistically significant only in the CR group. Body weight gain was reduced during the times when dietary restriction was enforced, and in a short-term study, both restricted diet treatments reduced the percentage of carcass protein.

9,10-Dimethyl-1,2-benzanthracene↗

PubMed1990

Effects of moderate dietary phosphorus restriction on intestinal absorption and external balances of phosphorus and calcium in growing female rabbits.

The effects of moderate dietary P restriction on intestinal net fluxes and external balances of P and Ca were studied in growing female albino rabbits that were fed a P-deficient diet for 10 consecutive days while they were housed in metabolism cages. Intestinal P secretion occurred during the first 24 h of P restriction and thereafter changed to absorption. During recovery, when the rabbits were consuming a normal diet, P absorption was significantly greater than either prerestriction control values or than in a separate group of time control rabbits. Phosphorus balance was negative during the 1st day of P restriction but thereafter became positive. This pattern occurred because intestinal P secretion changed to absorption and because urinary losses of P were negligible. Intestinal Ca absorption increased within 24 h of P restriction, reached maximal values by 4 days, and remained elevated for each of the remaining 6 days that dietary P was low. It also was elevated compared to P-sufficient time controls for 8 days after replenishment of dietary P. Despite increased intestinal absorption, Ca balance was significantly reduced during P restriction because of substantial hypercalciuria. Thus, selective dietary P restriction reduced the positive balances of both P and Ca that are characteristic of growth. We conclude that in growing rabbits moderate dietary P restriction induces both intestinal and renal adaptations that conserve this mineral; concomitantly, positive Ca balance is reduced. With dietary P replenishment, adaptations persist to restore the positive mineral balances that were lost because of dietary P restriction during growth.

Animals↗

PubMed1990

Effects of long-term dietary restriction on body temperature are modified with increasing age.

Effects of long-term dietary restriction on body temperature and its circadian changes were investigated in 3.5- and 14.5-month-old male Long-Evans rats. Animals were either fed and libitum or kept on a restricted diet for 8 weeks. Purina Lab Chow was constantly available to the ad libitum-fed groups, while half portions of their daily food consumption were given to age-matched diet-restricted groups every day. A highly significant lowering of body temperature in middle-aged diet-restricted (MR) rats was not observed until their food intake had been restricted for 5 weeks compared with that of the middle-aged ad libitum-fed (MA) group as well as that of the young diet-restricted (YR) rats. Eight weeks after diet restriction, both the circadian pattern of body temperature and its diurnal peak-trough difference remained almost unchanged in all four groups, while the average body temperature of MR rats was greatly lower than that of the YR group and that of MA animals. No significant difference in average body temperature was found between the young ad libitum-fed (YA) rats and the MA group. These data suggest that the average body temperature and its circadian changes in ad libitum-fed rats, at least before the age of 14.5 months, is not age-related, while the effect of dietary restriction on body temperature may be modified with increasing age.

Adaptation, Physiological↗