Molecular biological findings have indicated that the affinity and the density of presynaptic serotonin transporters may be subject to adaptive regulation, but the physiological conditions that may act to trigger such changes are presently unknown. By means of [3H]paroxetine binding to rat cortical membranes, we studied the influence of two ...

Chronic food restriction sensitizes animals to the rewarding effects of food, drugs and lateral hypothalamic electrical stimulation. The present study employed a curve-shift analysis of lateral hypothalamic self-stimulation (LHSS) to evaluate whether the elevated plasma corticosterone levels that accompany food restriction mediate the sensitization of reward. In Experiment 1, two ...

Daytime restriction of food availability phase-shifts the diurnal periodicity of plasma corticosterone (B) concentration in rats. However, the changes at the various functional levels in the hypothalamic-pituitary-adrenal (HPA) axis are not completely understood. We performed studies in two groups of Wistar rats, a control group with free access to food ...

The effect of a long-term 50% food restriction on plasma thyroid hormone levels was studied in adult male rats, which received their reduced daily amount of food either as one meal or 5 different meals. Compared to controls, a long-term food restriction reduced total 24 h-mean plasma T4, T3 and ...

Several studies have shown that, contrary to what occurs in rodents and in some invertebrate species, food restriction has no positive effect on longevity in Drosophila melanogaster. However, Chippindale et al. (1993) reported that flies subjected to food restriction, by modulating the yeast level, could live longer. In the present ...

Several data indicate that a blockade of stress-induced corticosterone secretion prevents the development of the stress-induced sensitization of the behavioral effects of drugs of abuse. In this report we investigated if an acute blockade of corticosterone secretion could reverse stress-induced sensitization once it is already established. Food restriction (90% of ...

A review of the literature and research on food restriction indicates that inhibiting food intake has consequences that may not have been anticipated by those attempting such restriction. Starvation and self-imposed dieting appear to result in eating binges once food is available and in psychological manifestations such as preoccupation with ...

To examine the relationship between heart function and plasma catecholamines upon food restriction, normal adult rats were fed 12 g or 6 g food/day for 14 days and 12 g food/day for 28 days. Food-restricted rats exhibited bradycardia, hypotension, and decreased rates of cardiac contraction (+dP/dt) as well as relaxation ...

We have investigated the susceptibility to peroxidation of erythrocytes from young, adult and old ad libitum (AL) fed, as well as from adult and old food restricted rats, measuring the rate of hemolysis under controlled peroxidative condition. Food restriction has been applied on an every-other-day (EOD) schedule starting from the ...

Although opioid administration induces food intake, the relationship between endogenous opioid synthesis and food consumption is unclear. Two studies examined the effects of food restriction and deprivation on opioid mRNA levels in the arcuate nucleus (ARC) of the rat. Body weight significantly decreased following food restriction and deprivation (P < ...

The effect of age and food restriction on the hepatic alkaline protease activity of 100,000 x g supernatant has been investigated using 7-, 16-, and 26-month-old Fischer 344 rats. The proteasome, a major component of alkaline protease activity, is activated by sodium dodecyl sulfate (SDS) and this property was exploited ...

Prior work has demonstrated that food restriction of mice markedly suppresses 12-O-tetradecanoylphorbol-13-acetate (TPA) promotion of skin papillomas and adrenalectomy prior to initiating food restriction completely reverses the tumor inhibitory effect of underfeeding. In the present experiment the effect of food restriction, with or without prior adrenalectomy, on 7,12-dimethylbenz[a]anthracene (DMBA)-induced lung ...

Pregnancy-associated growth of maternal and fetal tissues is likely mediated by insulin-like growth factors (IGF). To study the effect of food restriction during pregnancy on the IGF system, pregnant rats either had free access to food (control) or were fed 60% of control food intake. Serum and liver samples were ...

Pregnant and nonpregnant rats were subjected to one of four food intake schedules: ad libitum, 20, 40 and 60% of food restriction, during 20 days, with the objective of studying the distribution of energy between food-restricted mothers and offspring. The animals were anesthetized and the conceptuses were removed and separated ...

The effect of dehydration in the presence or absence of continued food intake on renal function was evaluated in chickens. In addition, renal transport of organic anions and cations under these conditions was assessed in vitro by uptake of 14C-para-aminohippuric acid and 14C-tetraethylammonium bromide by renal slices. Water restriction with ...

To investigate the role of the hormone vasopressin (VP) in mediating the response of an organism to food restriction stress-induced analgesia, tail flick latencies and scored qualitative behavioral responses were recorded in VP-containing (LE) rats and VP-deficient (DI) rats. These variables were measured under nonstressed (ad lib) and stressed (food ...

The present experiment examined endogenous ultradian rhythms and regulatory metabolic processes as two potential determinants of daily out-of-nest episodes (ONEs) and feeding episodes (FEs) in rats living in a 24-h environment. Two types of photoperiod were used: a Standard 12:12 h L/D schedule and a Skeleton 12:12 h schedule. During ...

The effects of a long term partial food restriction were studied in chickens and rats. In chickens the treatment resulted in increased plasma T4 levels while T4 levels in rats remained unchanged. Plasma T3 decreased in both species. In vitro hepatic outer ring deiodinating type I (ORD-I) activity was not ...

1. Six males and 24 female Cherry Valley Pekin ducklings were randomly allocated to each of 12 pens to test the effects of quantitative food restriction during the rearing period on the subsequent reproductive performance. At the end of the laying period (60 weeks) a "forced moult" was introduced and ...

Restriction of caloric intake increases longevity, slows the rate of functional decline, and reduces incidence of age-related disease in a variety of species. Most laboratory rodent studies have initiated restriction before puberty, whereas ongoing studies in nonhuman primates utilize restriction in adulthood. The mechanism of action of caloric restriction remains ...

Chronic food restriction lowers the threshold for lateral hypothalamic electrical self-stimulation (LHSS). This effect has previously been interpreted to reflect a sensitization of reward. In the present study a curve-shift method was used to explicitly differentiate effects of food restriction on brain stimulation rewarding efficacy and performance. Food restriction consistently ...

It has been suggested that impaired insulin action and/or insulin secretion in adult mammals could be a consequence of severe food restriction during fetal life. We have determined to what extent glucose homeostasis and insulin action are modified in male offspring of rats undernourished only during the first two trimesters ...

To investigate the beneficial effects of food restriction on systemic lupus erythematosus in NZB x NZW F1 mice, we separated the mice into three groups. One was fed a diet in which total food intake was reduced to 60% of normal from age 2 mo onward, while the animals were ...

This study was designed to determine if nutrient availability during gestation and early life modifies the effects of subsequent dietary intake on reproductive and lactation performance. Rat pups, whose mothers had been allowed free access to food or were food-restricted to 50% of ad libitum consumption were assigned to free ...

Data from our laboratory have demonstrated that food restriction leads to alterations in energy balance such as reduced energy expenditure as an energy conservation mechanism. Food restriction may be imposed on the animals in different ways. The most common is to give equal daily amounts of restricted food. Alternatively, food ...

It has been shown that restricting food in lactating rats for the first 2 weeks postpartum at a level of 60% of the ad-libitum daily ration increases the length of lactational dioestrus by about 7 days but little is known about correlated changes in hormone levels. In the first experiment ...

The present study addresses the role of prolactin as a regulator of migratory fattening in European quail (Coturnix coturnix). Plasma prolactin levels in captive birds undergoing migratory fattening in an outdoor aviary and in the laboratory were measured by radioimmunoassay with an antibody raised against recombinant-derived chicken prolactin. No strong ...

Two of 632 Fischer-344 rats in a food restriction study had spontaneous, bilateral, multicentric renal tubular cell carcinomas. Although there were 104 litters represented in this study, both rats that developed this rare neoplasm were from the same litter. The littermates, one male and one female, were in the food-restricted ...

Rates of conjugation of p-nitrophenol were studied in livers from normal and food-restricted rats perfused with either p-nitroanisole or p-nitrophenol. Female Sprague-Dawley rats had ad libitum access to a Purina 5001 nonpurified diet (control) or were given 65% of the intake of controls for 3 weeks. Livers were perfused with ...

Food restriction increases life span, reduces aging rate and affects a wide variety of biological functions. In rats, food restriction delays bone growth and reduces bone density and mineral content. We report the effects of aging and long-term (> 6.0 y) food restriction on several indices of bone growth and ...

1. Broilers were fed ad libitum or early-life food restricted and grown to 42 d of age to determine the influence of food restriction on the incidence and occurrence of ascites. 2. No differences in body weight, food conversion efficiency or arterial pressure index were observed although haematological data indicated ...

The effect of post-operative diet selection on the recovery rate of 100 children ages 3-17 years undergoing tonsillectomy and adenoidectomy (T & A) was studied. In the first 12 h after T & A children were allowed either a 'restricted' diet of only soft foods and liquids or a 'non-restricted' ...

Fifteen female ICR mice, 6-8 weeks old, were each exposed to 25 metacercarial cysts of Echinostoma caproni. To determine the effects of withholding food on survival, size and distribution of E. caproni in ICR mice, two groups of five each were maintained without food for 1 day (group A) or ...

We tested the hypothesis that voluntary running and moderate food restriction alter the acute phase response (APR), one index of nonspecific immune function. Hamsters were kept sedentary or permitted to run and were fed ad libitum or had food restricted for 20 days and were then injected intraperitoneally with saline ...

Acute aerobic exercise has been shown to elicit physiological changes characteristic of the acute phase response (APR), a nonspecific host defense response. Regular evocation of these changes may prime the immune system to improve resistance to disease. Because food deprivation is associated with an impaired APR, food restriction may prevent ...

Food restriction delays the loss of several cellular immune functions, retards the onset of many diseases during aging and, consequently, extends life span significantly in laboratory rodents. The present study was undertaken to determine whether the age-associated loss in immune function is linked to changes in microsomal and mitochondrial membranes ...

The objective of this study was to determine how food restriction (40% restriction of food intake) altered the age-related changes in the activities of Cu,Zn superoxide dismutase, catalase and glutathione peroxidase in liver, brain cortex, heart, kidney and intestinal mucosa obtained from 6-, 16- and 26-mo-old male Fischer 344 rats. ...

Long-term food restriction is known to inhibit development and aging in the rat. These actions may be mediated by the pineal hormone, melatonin, whose secretion is increased by food restriction. This mechanism was investigated by studying the effects of pinealectomy in ad libitum fed and food restricted rats of both ...

GM1 ganglioside (one week each at 10, 5, and 2.5 mg GM1/kg per day, ip) or gradual food restriction leading to a reduction in body weight to 75% of control were tested for their ability to block or reverse histopathologic and behavioral effects of trimethyltin (TMT) poisoning in rats. TMT ...

The effect of sugar restriction on the oral levels of mutans streptococci was studied in 20 subjects fulfilling three criteria: (1) having more than 300,000 CFU mutans streptococci/ml saliva, (2) harbouring both Streptococcus mutans and Streptococcus sobrinus in saliva, and (3) eating sugar frequently. The subjects were randomly divided into ...

Long-term dietary restriction programs which retard aging processes in rodents usually involve meal eating rather than the nibbling pattern of food intake of ad libitum fed rodents. Thus, the possibility arises that the antiaging action may at least in part result from an altered temporal pattern of food intake. This ...

Food, like water, is in short supply in the desert. We report a specialized mechanism used by a desert mouse for surviving prolonged food shortages. The key element of this adaptation is a large reduction in resting metabolism. After about 2 weeks of restricted food intake (50% of normal), the ...

The effects of food restriction (limited access to food for 2 h/day for 10 days) on lipoprotein lipase (LPL) activities and rates of fatty acid synthesis and glucose utilization in vivo in two superficial (interscapular and subcutaneous) and three deep abdominal white adipose tissue depots (parametrial, perirenal, and mesenteric) of ...

Chronic food restriction produces a variety of physiological and behavioral adaptations including a potentiation of the reinforcing effect of food, drugs and lateral hypothalamic electrical stimulation. Previous work in this laboratory has revealed that the lowering of self-stimulation threshold by food restriction is reduced by mu- and kappa-selective opioid antagonists. ...

Restriction of dietary calories reduces cancer formation in experimental animals and probably also in humans. This effect is generally attributed to the inhibitory effect of fasting on cell proliferation. Here we studied the effect of fasting on physiological cell death through apoptosis by using rat liver as a model. (i) ...

This study assessed the effect of food restriction on the metabolism of model monooxygenase substrates in the perfused rat liver. Female Sprague-Dawley rats has access ad lib. to a Purina 5001 nonpurified diet (control) or were given 65% of the intake of controls for 3 weeks. Livers were perfused with ...

The general and sexual activity of food restricted male broiler breeder poultry was assessed for evidence of behavioural changes associated with musculoskeletal lesions. The activity and fertility of male birds given betamethasone (an anti-inflammatory steroid) or saline were compared in a two-period crossover experiment. Behavioural changes occurred and the birds' ...

Hyperglycemia has been shown to contribute to the development and maintenance of insulin resistance in diabetic subjects and animal models of diabetes. Normalisation of circulating glucose levels is effective in restoring insulin action. The aim of the current study was to investigate the effects of mild food restriction on hyperglycemia ...

1. White Plymouth Rock chickens placed under 60% food restriction or ad libitum feeding, with or without metyrapone treatment, from either 4 to 6 (early) or 24 to 26 (late) d of age were exposed to high ambient temperatures (35 +/- 2 degrees C) from 36 to 43 d of ...

It is proposed that aging is induced by somatic replication of transposable elements (TEs). Most transposable elements in Drosophila reproduce by reverse transcription. Therefore inhibitors of reverse transcriptase were tested for their ability to retard aging in Drosophila melanogaster. Two inhibitors, phosphonoformic acid (PFA) and dideoxyinosine (ddI), were capable of ...