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At least 307 records · Page 17Linked to original sources

PubMed2006

Effect of 6-month calorie restriction on biomarkers of longevity, metabolic adaptation, and oxidative stress in overweight individuals: a randomized controlled trial.

CONTEXT: Prolonged calorie restriction increases life span in rodents. Whether prolonged calorie restriction affects biomarkers of longevity or markers of oxidative stress, or reduces metabolic rate beyond that expected from reduced metabolic mass, has not been investigated in humans. OBJECTIVE: To examine the effects of 6 months of calorie restriction, with or without exercise, in overweight, nonobese (body mass index, 25 to <30) men and women. DESIGN, SETTING, AND PARTICIPANTS: Randomized controlled trial of healthy, sedentary men and women (N = 48) conducted between March 2002 and August 2004 at a research center in Baton Rouge, La. INTERVENTION: Participants were randomized to 1 of 4 groups for 6 months: control (weight maintenance diet); calorie restriction (25% calorie restriction of baseline energy requirements); calorie restriction with exercise (12.5% calorie restriction plus 12.5% increase in energy expenditure by structured exercise); very low-calorie diet (890 kcal/d until 15% weight reduction, followed by a weight maintenance diet). MAIN OUTCOME MEASURES: Body composition; dehydroepiandrosterone sulfate (DHEAS), glucose, and insulin levels; protein carbonyls; DNA damage; 24-hour energy expenditure; and core body temperature. RESULTS: Mean (SEM) weight change at 6 months in the 4 groups was as follows: controls, -1.0% (1.1%); calorie restriction, -10.4% (0.9%); calorie restriction with exercise, -10.0% (0.8%); and very low-calorie diet, -13.9% (0.7%). At 6 months, fasting insulin levels were significantly reduced from baseline in the intervention groups (all P<.01), whereas DHEAS and glucose levels were unchanged. Core body temperature was reduced in the calorie restriction and calorie restriction with exercise groups (both P<.05). After adjustment for changes in body composition, sedentary 24-hour energy expenditure was unchanged in controls, but decreased in the calorie restriction (-135 kcal/d [42 kcal/d]), calorie restriction with exercise (-117 kcal/d [52 kcal/d]), and very low-calorie diet (-125 kcal/d [35 kcal/d]) groups (all P<.008). These "metabolic adaptations" (~ 6% more than expected based on loss of metabolic mass) were statistically different from controls (P<.05). Protein carbonyl concentrations were not changed from baseline to month 6 in any group, whereas DNA damage was also reduced from baseline in all intervention groups (P <.005). CONCLUSIONS: Our findings suggest that 2 biomarkers of longevity (fasting insulin level and body temperature) are decreased by prolonged calorie restriction in humans and support the theory that metabolic rate is reduced beyond the level expected from reduced metabolic body mass. Studies of longer duration are required to determine if calorie restriction attenuates the aging process in humans. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00099151.

Adult↗

PubMed2001

Effects of maternal iron restriction in the rat on blood pressure, glucose tolerance, and serum lipids in the 3-month-old offspring.

Epidemiologic studies have demonstrated associations between low birth weight and increased rates of adult diseases such as hypertension and diabetes. Maternal iron restriction in the rat has been reported to both reduce birth weight and to elevate blood pressure at 40 days of age. The aim of the present study was to extend these findings to investigate the effects of maternal iron restriction on glucose tolerance and serum lipids, 2 important components of the metabolic syndrome, in adult offspring. Blood pressure, glucose tolerance, and serum lipids were measured in the 3-month-old offspring of iron-restricted dams. Rats were placed on control or iron-restricted diets 1 week before mating. At term, dams on the iron-restricted diet were anemic with decreased haemoglobin, red blood cell (RBC) count, hematocrit, and mean RBC volume compared with controls. Neonates from iron-restricted litters were more severely anemic than the dams. At birth, body weight was lower in the offspring of iron-restricted dams than in controls and was still decreased at 3 months of age. At this same age, systolic blood pressure was significantly elevated in the offspring of iron-restricted dams. Glucose tolerance was improved in the maternal iron-restricted group. Fasting serum insulin levels were not different between the control and maternal iron-restricted groups. Fasting serum triglyceride was decreased in the offspring of iron-restricted dams compared with controls. Fasting serum cholesterol and free fatty acid concentrations were similar in both groups. These results suggest that maternal iron restriction has long-term effects on physiology and metabolism in the offspring. Some of these findings are comparable to those reported for the maternal protein-restriction model. It is thus speculated that the long-term effects of maternal dietary restriction may result from common fetal metabolic responses to this restriction.

Animals↗

PubMed1999

Restricting access to palatable foods affects children's behavioral response, food selection, and intake.

BACKGROUND: Restricting children's access to palatable foods may appeal to parents as a straightforward means of promoting moderate intakes of foods high in fat and sugar; however, restricting access to palatable foods may have unintended effects on children's eating. The efficacy of restricting children's access to palatable foods as a means of promoting patterns of moderate intake of those foods is unknown. OBJECTIVE: Two experiments were conducted to test the hypothesis that restricting access to a palatable food enhances children's subsequent behavioral responses to, selection of, and intake of that restricted food. DESIGN: Both experiments used a within-subjects design to examine the effects of restricting access to a palatable food on children's subsequent behavior, food selection, and food intake. The first experiment examined the effects of restriction within and outside the restricted context and the second experiment focused on the effects within the restricted context. RESULTS: In both experiments, restricting access to a palatable food increased children's behavioral response to that food. Experiment 2 showed that restricting access increased children's subsequent selection and intake of that food within the restricted context. CONCLUSIONS: Restricting access focuses children's attention on restricted foods, while increasing their desire to obtain and consume those foods. Restricting children's access to palatable foods is not an effective means of promoting moderate intake of palatable foods and may encourage the intake of foods that should be limited in the diet.

Analysis of Variance↗

PubMed1992

Food restriction increases detoxification of polycyclic aromatic hydrocarbons in the rat.

It is well known that food restriction diminishes tumor formation, but mechanisms responsible are difficult to define because multiple physiological changes result from dietary alterations. Studies in this report were designed to focus specifically on the effects of food restriction on hepatic metabolism of polycyclic aromatic hydrocarbons following liver transplantation. By placing livers from food-restricted and untreated rats into naive controls, the effects of diet could be restricted to the liver. After a 15 min infusion of [3H]benzo[a]pyrene under these conditions, food restriction increased polar metabolites in liver (70 pmol/g) and blood (8 pmol/ml) compared to controls approximately 2-fold. Four hours after liver transplantation, levels of polar metabolites in blood were diminished by approximately 50% but were still approximately 2-fold higher in the food-restricted than in the control group. Lung, kidney, spleen, adrenal, ovary, colon, heart and brain also contained higher levels of polar metabolites in the food-restricted than in the control group. The more hydrophobic glucuronides and sulfate conjugates accounted for most of the elevation in polar metabolites in blood from the food-restricted group. In spite of the increase in circulating metabolites in blood of food-restricted animals, DNA binding in liver, lung and kidney was identical in tissues from control and food-restricted groups. In order to evaluate the hypothesis that food restriction stimulated the release of hepatic benzo[a]pyrene metabolites, a liver perfusion model was employed. Maximal rates of release of polar metabolites into the effluent perfusate were approximately 30 and approximately 45 nmol/g/h in livers of control and food-restricted rats respectively. Moreover, rates of metabolism of the model compound p-nitroanisole and glucuronidation of p-nitrophenol were also approximately 2-fold higher in livers from food-restricted than control rats. However, rates of monooxygenation were the same in microsomes prepared from livers of food-restricted or control animals. These results support the hypothesis that food restriction enhances the supply of cofactors which stimulate metabolism of polycyclic aromatic hydrocarbons. This detoxification process may be an important mechanism involved in the protective action of reduced food intake.

Animals↗

PubMed2002

Effect of moderate caloric restriction and/or weight cycling on mammary tumor incidence and latency in MMTV-Neu female mice.

Recently, we reported that intermittent caloric restriction-refeeding reduces mammary tumor (MT) incidence and extends latency in murine mammary tumor virus (MMTV)-transforming growth factor (TGF)-a mice to a greater extent than does chronic caloric restriction. Here, this same weight-cycling protocol was applied to MMTV-Neu female mice, which develop MTs at a much younger age than do TGF-a mice. This study consisted of three experimental groups: mice fed an AIN-93M diet ad libitum, mice intermittently fed an AIN-93 modified diet (2-fold increase in protein, fat, vitamins, and minerals) at 50% of the amount fed to the ad libitum-fed mice for 3-wk intervals and then fed an AIN-93M diet ad libitum for 3-wk intervals, and mice chronically restricted, pair fed to the intermittently restricted mice by feeding 2:1 mixtures of AIN-93M-AIN-93 modified diets for each 6-wk feeding interval. Mice were euthanized when MTs reached a length of 20 mm or at 80 wk of age. Cumulative caloric intake was 10% lower (not significant) for intermittently restricted mice and 16% lower (P < 0.05) for chronically restricted mice than for ad libitum-fed mice. Final body weights were significantly different as follows: ad libitum-fed > intermittently restricted > chronically restricted. Fat pad weights were greater in ad libitum-fed than in intermittently restricted and chronically restricted mice. MT incidence of ad libitum-fed mice was 37% compared with 22% for intermittently restricted mice and 33% for chronically restricted mice (not significant). There were no differences in MT weight or number among the groups. These results indicate that intermittent caloric restriction-refeeding provides a moderate protective effect, whereas chronic caloric restriction provides no significant protection against MT development in transgenic Neu mice.

Adenocarcinoma↗

PubMed1989

Food restriction retards body growth and prevents end-stage renal pathology in remnant kidneys of rats regardless of protein intake.

The objectives of this study were to evaluate the effects of food restriction (without protein or phosphorus restriction) and protein restriction (without the restriction of other nutrients or calories) on the outcome of the remnant kidney model of chronic renal failure in rats. After 5/6 nephrectomy, rats were assigned to one of the following dietary groups: group I (control-ad libitum) consumed a 21% casein diet ad libitum; group II (food restriction with protein restriction) consumed 36% less calories, protein and minerals than group I; group III (food restriction without protein restriction) consumed 36% less calories and minerals than group I, but equivalent amounts of protein; group IV (protein restriction) consumed 38% less protein than group I, but equivalent amounts of calories and minerals; group V (NaCl restriction) consumed 40% less sodium chloride than group I, but equivalent amounts of all other nutrients. All groups consumed equivalent amounts of calcium, phosphorus and vitamins. Groups II and III experienced retardation of growth in comparison to groups I, IV and V. The food-restricted groups II and III, but not groups IV and V, had less proteinuria than group I 20 weeks postablation. By 21 weeks postablation, the kidneys from group I showed severe parenchymal damage, characteristic of end-stage renal pathology. These changes were prevented in the food-restricted groups II and III, but not in groups IV and V. The percentage of glomeruli with severe structural damage was less in groups II (27.3 +/- 8.8) and III (26.9 +/- 7.5) compared with group I (72.4 +/- 7.8). In contrast, the corresponding values in groups IV and V were not significantly different from group I. Interstitial volume (the percentage of tubulointerstitium which is interstitium) which was proportional to the severity of tubular damage was significantly lower in groups II (25.1 +/- 4.5) and III (20.4 +/- 2.8) when compared with groups I (48.1 +/- 3.0), IV (44.4 +/- 6.6), or V (41.9 +/- 4.2). An interstitial volume less than 30 correlated with well preserved renal histology, whereas a value greater than 40 was indicative of end-stage renal pathology. These results indicate that the restriction of carbohydrate, fat, and minerals (except for calcium and phosphorus) retarded growth and prevented the development of end-stage renal pathology in the remnant kidney model of chronic renal failure in rats, regardless of whether protein was restricted or not.(ABSTRACT TRUNCATED AT 400 WORDS)

Animal Feed↗

PubMed2004

Energy restriction initiated at different gestational ages has varying effects on maternal weight gain and pregnancy outcome in common marmoset monkeys (Callithrix jacchus).

With relatively high fertility and short lifespan, marmoset monkeys (Callithrix jacchus) may become useful primate models of prenatal nutritional effects on birth condition and adult disease risk. The present study determined the effects of energy restriction to 75% of expected ad libitum consumption during mid- (day 66) or late (day 99) gestation on maternal weight, fetal growth and pregnancy outcomes in this species. Mid-restriction reliably induced the loss of pregnancy before term, at 92 d, on average. Of the late-restricted pregnancies, four of seven were normal term length while three were preterm deliveries, at 101, 117 and 132 d. Control females had a mean mid-pregnancy weight gain of 0.67 g/d while mid-restricted females lost -0.65 g/d, on average. Control pregnancies averaged a 1.06 g/d gain during late pregnancy, while energy-restricted females lost -0.67 g/d, on average. Restriction-related weight change was highly variable, ranging from +0.55 to -2.56 g/d for mid-restriction pregnancies and from +0.79 to -3.91 g/d for late-restriction pregnancies. For mid-restriction pregnancies, the number of restriction days was best explained by linear weight change and total weight loss while the number of restriction days in late pregnancy was best explained by linear weight change alone. In late-restriction pregnancies, smaller females had higher daily weight losses. Restrictions did not induce litter-size reduction or growth restriction in those infants that were delivered at term but the size of aborted fetuses suggested that at least some pregnancies lost preterm may have involved impaired intra-uterine growth.

Animals↗

PubMed1997

Effect of caloric restriction on pre-malignant and malignant stages of mammary carcinogenesis.

Caloric restriction has documented beneficial effects on numerous diseases including cancer, yet the mechanism(s) that accounts for these wide ranging benefits is unknown. Part of the difficulty in defining mechanisms has been the long-term nature of experimental protocols in which these beneficial effects have been observed and the inherent difficulty of investigating mechanisms in such studies. The experiments reported were designed: (1) to determine if caloric restriction would inhibit mammary carcinogenesis in a model for this disease process that is 35 days in duration; (2) to determine if progression from pre-malignant to malignant stages of mammary carcinogenesis was affected by caloric restriction; and (3) to explore whether the effects of caloric restriction were associated with changes in adrenal function. Mammary carcinogenesis was induced in female Sprague-Dawley rats by the i.p. administration of 1-methyl-1-nitrosourea (50 mg/kg body weight) at 21 days of age. Rats were randomized to one of four dietary treatment groups: ad libitum fed, or restriction of food intake to 90, 80 or 60% of the ad libitum intake. Rats were palpated for detection of mammary tumors and all mammary lesions excised at necropsy were histologically classified. Twenty-four-hour collections of urine were obtained at weekly intervals throughout the 35-day experiment. Urine was assayed for corticosterone by direct radioimmunoassay. Caloric restriction resulted in both a dose dependent prolongation of latency to palpable carcinomas (P < 0.01) and a reduction in final incidence of mammary cancer; the dose response was linear (P < 0.05). The percentage of pre-malignant mammary lesions in a group increased with increasing degree of caloric restriction, whereas the percentage of carcinomas decreased (P < 0.05). The level of cortical steroid increased linearly with increasing caloric restriction (P < 0.01) an effect that was not attenuated over time. Poisson regression analyses with the number of cancers per rat as the dependent variable, level of caloric restriction as the independent variable and urinary cortical steroid excretion as a co-variate were performed. These analyses indicated that the variation in cancers per rat, irrespective of the treatment group to which an animal was assigned, could be accounted for by urinary cortical steroid excretion (P<0.05); i.e. urinary cortical steroid excretion was an independent predictor of an animal's carcinogenic response. The data reported in this study support the use of a short term model to study the mechanism(s) by which caloric restriction inhibits mammary carcinogenesis and point to both a stage in the disease process, the conversion of pre-malignant to malignant cells, and a target tissue (adrenal gland) and chemical species (adrenal cortical steroid) that may be involved in mediating the protective effects of energy restriction. These data indicate the feasibility of identifying a chemical basis for the protective effect of caloric restriction that is independent of energy restriction per se and this, in turn, indicates that it may be possible to circumvent the practical problem of implementing a program of chronic energy restriction in human populations, yet still achieve the wide-ranging health benefits of such a program.

Adenocarcinoma↗

PubMedDate not supplied

Meta-analysis of dietary restriction during fecal occult blood testing.

CONTEXT: Dietary restriction is often recommended during fecal occult blood testing (FOBT) as a means of increasing test accuracy, but concern surrounds whether such restriction also reduces the chance that patients will complete the test. PURPOSE: We conducted a systematic review and meta-analysis to determine if advice about dietary restrictions affects the rate of completion of FOBT and the rate of positive results. METHODS: We searched the MEDLINE database and hand-searched the bibliographies of other systematic reviews and clinical practice guidelines to identify randomized trials of advice to perform dietary restriction during FOBT. We included only trials that reported the proportion of patients who completed the occult blood tests (completion rate). When such information was available, we also recorded the proportion of patients who had positive test results (positivity rate). RESULTS: Five randomized trials met our inclusion criteria. All used guaiac-based Hemoccult tests; none reported results from rehydrated test slides. In four trials, there was little or no difference in test completion between patients assigned to dietary restriction and those with no restriction. In one small trial that used an especially restrictive diet, completion was 21 percentage points lower in the restricted group. Positivity rates were reported in four trials, none of which found a statistically significant difference between groups. Meta-analysis showed no difference in the summary positivity rate between those assigned to dietary restriction versus those not restricted (difference in positivity rate, 0%; 95% CI, -1% to 1%). CONCLUSIONS: Available data suggest that advice to perform modest dietary restriction during unrehydrated FOBT does not affect the completion rate, but more severe restrictions may. Dietary restriction also does not appear to affect positivity rates. On the basis of these data, physicians do not need to advise patients to restrict their diet for nonrehydrated FOBTs.

Aged↗

PubMed2006

Selective carbohydrate or protein restriction: effects on subsequent food intake and cravings.

In order to determine the effects of selective food restriction on subsequent food intake and cravings, participants were randomly assigned to one of three conditions: carbohydrate-restriction, protein-restriction, or control (no restriction). Participants in the restriction conditions were asked to restrict their intake of either complex carbohydrates or animal proteins for 3 days, before coming to the laboratory for an experimental session. During the experimental session, participants' food intake, cravings, and affect were measured. The results indicated that selective food restriction resulted in selective behavioural consequences. Specifically, carbohydrate-restricted participants consumed more of a high-carbohydrate food than did controls or protein-restrictors, in addition to reporting more cravings for high-carbohydrate foods over the restriction period. Protein-restricted participants reported more cravings for high-protein foods over the restriction period, in comparison to controls and carbohydrate-restrictors; however, protein-restricted participants did not consume more of the particular high-protein food presented to them in the laboratory. The roles of dietary restraint and negative affect in influencing cravings and food intake are discussed. Overall, selective food restriction is demonstrated to have negative psychological and behavioural consequences.

Adolescent↗

PubMed1999

Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) for the identification of Trichinella isolates.

In the present study, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis was developed to identify 5 species (Trichinella spiralis, Trichinella britovi, Trichinella nativa, Trichinella nelsoni and Trichinella pseudospiralis) and 3 phenotypes of uncertain taxonomic status (Trichinella T5, T6, and T8). Eleven restriction endonucleases were used to restrict 3 DNA fragments (1) a 2800 bp fragment of the 43 kDa excretory-secretory (E-S) protein gene, (2) a 1250 bp fragment amplified with the primer pair SB147A and (3) a 372 bp fragment amplified with the primer pair SB372A. This RFLP method allows the identification of the 8 Trichinella phenotypes as follows: T. spiralis by the HinfI or DdeI endonuclease restriction of the 2800 bp fragment; T. nativa by the RsaI restriction of the 2800 bp fragment, or by the AluI restriction of the 1250 bp fragment; T. britovi and Trichinella T8 by the AluI restriction of the 1250 bp fragments, and can be discriminated between them by the SspI restriction of the 2800 bp fragment; T. pseudospiralis by the MspI restriction of the 372 bp fragment; T. nelsoni by the HhaI or AluI restriction of the 2800 bp fragment; Trichinella T5 by the HhaI restriction of the 2800 bp fragment; Trichinella T6 by the AluI restriction of the 1250 bp fragment; and Trichinella T8 by the SspI or RsaI restriction of the 2800 bp fragment. This study reveals also an intraspecifies polymorphism in the 2800 bp and 1250 bp fragments for T. britovi, Trichinella T5 and T6.

Animals↗

PubMed2004

Effect of early feed restriction and enzyme supplementation on digestive enzyme activities in broilers.

The effect of feed restriction and enzymatic supplementation on intestinal and pancreatic enzyme activities and weight gain was studied in broiler chickens. Quantitative feed restriction was applied to chickens from 7 to 14 d of age. An enzyme complex mainly consisting of protease and amylase was added to the chicken ration from hatching to the end of the experiment. Birds subjected to feed restriction whose diet was not supplemented showed an increase in sucrase, amylase, and lipase activities immediately after the restriction period. Amylase, lipase, and chymotrypsin activities were higher in chickens subjected to feed restriction and fed a supplemented diet than in those only subjected to feed restriction. Trypsin activity increased after feed restriction and after supplementation, but there was no interaction between these effects. Early feed restriction had no effect on enzyme activity in 42-d-old chickens. Chickens subjected to early restriction and fed the supplemented diet presented higher sucrase, maltase, and lipase activities than nonsupplemented ones (P < 0.05). There was no effect of early feed restriction or diet supplementation on weight gain to 42 d. Percentage weight gain from 14 to 42 d of age was equivalent in feed-restricted and ad libitum fed birds. Feed-restricted broilers fed a supplemented diet showed a higher percentage weight gain than nonsupplemented birds. We conclude that enzymatic supplementation potentiates the effect of feed restriction on digestive enzyme activity and on weight gain.

Amylases↗

PubMed1993

Restriction sites as identification tags for the gene catalog: a 2D gel model.

In our effort to collect, organize and assemble data from lymphocyte cDNA libraries, we assign DNA restriction sites collectively to the spots on two-dimensional (2D) gel patterns. In order to test the efficiency and reliability of such an approach, we have modeled the restriction analysis of cDNA libraries with a panel of restriction endonucleases. The work has two parts. In the first, we have chosen 255 proteins from the EMBL data base and determined whether or not their coding sequences contain restriction sites for the enzymes of our choice. In order to apply a sufficient discriminatory power we decided to use a relatively large number of cleaving enzymes with low and high cutting frequencies. In total, 13 restriction enzymes were chosen, which could distinguish 2(13) or 8192 different restriction site combinations. We have compiled a table in which the absence or presence of restriction sites yields a pattern of 'zeros' and 'ones'. Such a restriction pattern can be read as a binary number. The binary numbers with maximally 13 digits would uniquely assign each of the 255 proteins if the nucleotide sequences would be truly at random. As the restriction sites are not randomly distributed, the 'typing' does not yield a unique assignment. The choice of sequences was not random either. In fact, there are some human nucleotide sequences which possess the same cut number (the decimal equivalent of the binary number representing the restriction pattern). In spite of this redundancy, 141 coding sequences could uniquely be distinguished by the above treatment. In the second part of the project we have used the above mentioned coding sequences to prepare two-dimensional maps (plots of charge vs size) of the same kind as one obtains from experimental 2D gels and submitted such a map together with 13 maps of restriction enzyme treated populations to a computer image analysis. Ideally, one would expect results (cut numbers) congruent to those obtained in the first part of the work. In the modeled system we were confronted with 2D maps which closely resembled the experimental situation (e.g. some spots were close together and overlapping) and instances of incorrect spot detection yielding 'false cut numbers'. From 255 proteins we were able to assign unequivocally 161 proteins. To implement the model in an actual experiment we will perform the digestion with the restriction enzymes in duplicate, and only spots assigned the same cut number upon the two independent treatments will be considered as carrying a valid restriction tag.

Base Sequence↗

PubMed2001

Effects of maternal iron restriction in the rat on hypoxia-induced gene expression and fetal metabolite levels.

The mechanism by which maternal Fe deficiency in the rat causes fetal growth retardation has not been clearly established. This study compared the effects on the fetuses from dams fed a control diet with two groups of dams fed Fe-restricted diets. One Fe-restricted group was fed the Fe-restricted diet for 1 week prior to mating and throughout gestation and the second Fe-restricted group was fed the Fe-restricted diet for 2 weeks prior to mating and throughout gestation. On day 21 of gestation Fe-restricted dams, and their fetuses, were anaemic. Fetal weight was reduced in both Fe-restricted groups compared with controls. Expression of hypoxia-inducible factor (HIF)-1alpha and vascular endothelial growth factor (VEGF) are induced by hypoxia. The levels of HIF-1alpha mRNA were highest in placenta, then in kidney, heart and liver but were not different between the groups. Levels of plasma VEGF were not different between the groups. Maternal plasma triacylglycerol was decreased in the 1-week Fe-restricted dams compared with controls. Maternal plasma cholesterol and free fatty acid levels were not different between the groups. In fetal plasma, levels of triacylglycerol and cholesterol were decreased in both Fe-restricted groups. In maternal plasma, levels of a number of amino acids were elevated in both Fe-restricted groups. In contrast, levels of a number of amino acids in fetal plasma were lower in both Fe-restricted groups. Fetal plasma lactate was increased in Fe-restricted fetuses but fetal plasma glucose and beta-hydroxybutyrate were not affected. These changes in fetal metabolism may contribute to fetal growth retardation in this model. This study does not support the hypothesis that the Fe-restricted fetus is hypoxic.

Amino Acids↗

PubMed1991

Suppression of natural killer cell activity by ethanol consumption and food restriction.

Effects of 4-week food restriction and ethanol consumption on natural killer (NK) cell activity and carcass composition were evaluated. Female, C57BL/6 mice given water (H2O) or ethanol (20% w/v, ETOH) ad libitum were placed in one of three dietary groups: unrestricted (UNR), moderately restricted (MR, 2.2 g/day), or severely restricted (SR, 1.8 g/day). Food restriction alone (MR, SR) significantly reduced body, spleen, and thymus weights; carcass lipid content (SR only); spleen cell number; and baseline and interleukin-2 (rIL-2) stimulated NK cell activities. Ethanol consumption was unaffected by food restriction and in restricted mice it did not suppress food intake. Thus, average calories derived from ethanol increased from 30% (UNR) to 40% (SR) with the degree of food restriction in these groups. Mice given ethanol and restricted food intake had at least as heavy or heavier body, spleen, and thymus weights than water-drinking (H2O) counterparts. Spleen cell number was reduced in ethanol-consuming (ETOH), food restricted groups compared with UNR H2O control. Baseline NK cell activity was suppressed 50% to 90% in all ETOH and food-restricted groups. rIL-2 stimulated NK cell activity was suppressed 18% to 76% in food restricted mice independent of ethanol intake. These results indicate that supplementary ethanol calories did not enhance NK cell activity in UNR ETOH mice, nor did they protect splenic NK cell activity from the suppressant effects of food restriction. Ethanol consumption significantly increased carcass lipid content in all groups compared with their H2O counterparts. This increase was largely responsible for the preservation of body weight in ETOH mice especially during food restriction.

Alcohol Drinking↗

PubMed1980

Rib cage and abdominal restrictions have different effects on lung mechanics.

The effects of a variety of restrictive procedures on lung mechanics were studied in eight healthy subjects. Rib cage restriction decreased total lung capacity (TLC) by 43% and significantly increased elastic recoil and maximum expiratory flow (MEF). Subsequent immersion of four subjects with rib cage restriction resulted in no further change in either parameter; shifts of blood volume did not reverse recoil changes during rib cage restriction. Abdominal restriction decreased TLC by 40% and increased MEF and elastic recoil, but recoil was increased significantly less than was the case with rib cage restriction. Further, at a given recoil pressure, MEF was less during rib cage restriction than during either abdominal restriction or no restriction. Measurements of the unevenness of inspired gas distribution by the single-breath nitrogen technique showed increased unevenness during rib cage restriction, which was significantly greater than that during abdominal restriction. We conclude that lung volume restriction induces changes in lung function, but the nature of these changes depends on how the restriction is applied and therefore cannot be ascribed to low lung volume breathing per se.

Abdomen↗

PubMed1999

Acute right ventricular restrictive physiology after repair of tetralogy of Fallot: association with myocardial injury and oxidative stress.

BACKGROUND: Acute right ventricular (RV) restrictive physiology after tetralogy of Fallot repair results in low cardiac output and a prolonged stay in the intensive care unit (ICU). However, its mechanism remains uncertain. METHODS AND RESULTS: In the first 24 hours after tetralogy of Fallot repair (n=11 patients), serial prospective measurements were performed of cardiac troponin T, indexes of NO production (NO(2)(-) and NO(3)(-) combined as NOx), and iron metabolism and antioxidants. RV diastolic function was assessed by transthoracic Doppler echocardiography. Patients who had a long stay in the ICU were characterized by restrictive RV physiology (nonrestrictive group [n=7]: 3.0+/-0.6 days [mean+/-SD]; restrictive group [n=4]: 10.7+/-3.1 days). Troponin T peak concentration and the area under its concentration-time curve (AUC) were higher in the restrictive RV group (peak: restrictive group 17. 0+/-2.8 microg/L, nonrestrictive group 10.4+/-4.6 microg/L, P<0.03; AUC: restrictive group 268.8+/-73.6 microg. h(-1). L(-1), nonrestrictive group 136.2+/-48.3 microg. h(-1). L(-1), P<0.03). Plasma NOx/creatinine concentrations were higher in the restrictive group than the nonrestrictive group at 2 hours after bypass (restrictive group 1.3+/-0.4, nonrestrictive group 0.8+/-0.2; P=0. 04) but were similar by 24 hours. Iron loading peaked 2 to 10 hours after bypass and was more severe in the restrictive group (peak transferrin saturation: restrictive group 83.9+/-13.0%, nonrestrictive group 58.3+/-16.2%, P=0.05; minimum total iron-binding capacity: restrictive group 0.59+/-0.21%, nonrestrictive group 0.76+/-0.06%, P=0.04; minimum iron-binding antioxidant activity to oxyorganic radicals: restrictive group 9. 5+/-22.4%, nonrestrictive group 50.6+/-11.4%, P=0.01). CONCLUSIONS: After tetralogy of Fallot repair, acute restrictive RV physiology is associated with greater intraoperative myocardial injury and postoperative oxidative stress with severe iron loading of transferrin.

Child, Preschool↗

PubMed1997

Phase-advanced daily rhythms of melatonin, body temperature, and locomotor activity in food-restricted rats fed during daytime.

This study was performed to investigate possible effects of a timed caloric restriction on the light-dark (LD) synchronization of four biological rhythms pair-studied in the same animals. In Experiment 1, food-restricted rats kept under a photoperiod of 12 h light:12 h dark received 50% of previous ad libitum food 2 h after the onset of light. Their daily rhythm of pineal melatonin and rhythms of plasma melatonin and corticosterone were examined and compared to those of ad libitum control rats after 1 or 2 months of food restriction. A significant phase advance (about 2 h) was found for the pineal melatonin rhythm and for the daily onset of plasma melatonin. Timing of nocturnal peak of circulating corticosterone was unchanged, and a diurnal peak anticipated food presentation by about 2 h. In Experiment 2, effects of a timed caloric restriction under 12L:12D were studied on the expression of daily rhythms of body temperature and locomotor activity. To discriminate between the effects of timed meal feeding and those of the added caloric restriction, these rhythms were analyzed in food-restricted rats, as in Experiment 1, and were compared to those in sham-restricted rats, concomitantly fed twice more than food-restricted rats (i.e., a timed meal feeding without caloric restriction). Acrophase of the nocturnal peak of body temperature rhythm reached the greatest phase advance (7 h) in food-restricted rats, in which it was close to LD transition. The nocturnal component of locomotor activity rhythm also was markedly phase advanced (6 h) by caloric restriction, as indicated by wheel-running and general activity occurring form early afternoon to midnight. A smaller 4-h phase advance of the nocturnal peak of body temperature also was observed in sham-restricted rats, although the onset of locomotor activity rhythm apparently was unaffected by meal feeding and the end of activity rhythm was phase advanced by 2 h. These results indicate that timed caloric restriction is a potent phase-shifting agent that interacts with the LD cycle zeitgeber. This nonphotic stimulus phase advances melatonin, corticosterone, body temperature, and activity rhythms to different extents and thus suggests a change in the internal synchronization of the circadian system.

Animals↗