PubMed HealthSearch

SEARCH · PubMed Health

Results for “Refeeding”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

Early hepatic protein responses to dietary restriction-refeeding in Japanese quail: A proteomic investigation.

Feed intake and refeeding after nutrient scarcity induce rapid metabolic adaptations in the poultry liver; however, hepatic proteomic recovery pathways in the early hours post-refeeding remain poorly defined. This study aimed to characterize early liver protein signatures in Japanese quail (Coturnix japonica) recovering from nutritional stress under two refeeding conditions. Eighteen 12-week-old male quails (245.20 ± 0.213 g) were assigned to three groups (n = 6): control fed ad libitum (12.13 MJ/kg), 24 h feed deprivation followed by 6 h refeeding, and 24 h low metabolizable energy (6.30 MJ/kg) diet followed by 6 h refeeding. In total, 854 proteins were identified, of which 515 met the filtering criteria. The low metabolizable energy refeeding showed higher abundance of proteins linked to ATP binding and carbohydrate/carboxylic acid metabolism, alongside detoxification-related proteins, while suppressing translation/RNA-binding machinery and antioxidant pathways. Feed-deprived refeeding enriched in oxidative phosphorylation and mitochondrial complex I assembly with reduced cytoplasmic translation, NMD-related components, and sulfur compound metabolism. A direct comparison indicated divergent recovery strategies: low metabolizable energy refeeding mainly reflected oxidoreductase activity and translation initiation, whereas feed-deprived refeeding potentially enriched mitochondrial ATP production and glutathione-based defenses. Our analysis indicate that 6 h of refeeding initiates an early, incomplete recovery toward hepatic homeostasis, with the severity of prior nutritional restriction dictating distinct liver metabolic priorities. Collectively, these findings might provide a preliminary understanding of the hepatic mechanisms involved in recovery from nutrient deprivation and may help in the development of feeding strategies for managing metabolic recovery in poultry. However, these findings should be considered hypothesis-generating pending further validation.

Animals

Fasting-refeeding regimes induce compensatory growth and muscle transcriptomic remodeling in juvenile Qihe gibel carp (Carassius gibelio var. Qihe).

Compensatory growth, an important adaptive response in fish, holds considerable potential for improving feeding efficiency in aquaculture. To identify an optimal fasting-refeeding strategy for juvenile Qihe gibel carp (Carassius gibelio var. Qihe) and to clarify the mechanisms underlying the compensatory growth, we divided two-month-old fish into four groups, namely S0 group (continuous feeding for 28 days), S2 group (4 cycles of 2-day fasting followed by 5-day refeeding), S4 group (fasting for 4 days followed by refeeding for 24 days), and S8 group (fasting for 8 days followed by refeeding for 20 days), then growth performance, muscle tissue morphology, biochemical responses, and muscle transcriptomic profiles under different feeding regimes were investigated. After a 28-day aquaculture experiment, fish in the S4 group exhibited significantly greater body length and weight than those in the S0, S2, and S8 groups, indicating over-compensatory growth. Histological analysis further showed that muscle growth in the S4 group was mainly associated with myofiber hyperplasia. Different feeding regimes also induced distinct changes in hepatic antioxidant and metabolic enzyme activities, as well as intestinal digestive enzyme activities. Transcriptome analysis revealed that the forkhead box O (FoxO) signaling pathway was significantly enriched during compensatory growth. Key genes, including serum/glucocorticoid regulated kinase 1 (sgk1) and insulin receptor substrate 1 (irs1), were predicted to play important roles in this process. Overall, these results indicate that fasting for 4 days followed by refeeding for 24 days (the S4 regime) is the optimal strategy for inducing compensatory growth in juvenile Qihe gibel carp. This study provides new insights into the morphological, physiological, and molecular basis of compensatory growth and offers a scientific foundation for developing efficient and sustainable feeding strategies for this species.

Animals

Metabolic control of phosphorylase conversion in muscle. Effect of fasting and refeeding on the response of rat diaphragm glycogen phosphorylase, cyclic AMP Dependent protein kinase, and phosphorylase b kinase to adrenergic stimulation.

The influence of fasting and refeeding on the response to adrenergic stimulation of several enzymes involved in glycogen metabolism has been investigated in the isolated, intact rat diaphragm. The in vitro response of the phosphorylase system to terbutaline was found to decrease markedly following fasting. A pronounced increase in this response was seen upon refeeding. This increased responsiveness was normalized by incubation of isolated tissues with palmitate (1.5 mM). Plasma free fatty acid concentration was increased in fasted rats compared to the value found in refed animals. The effect of terbutaline on cyclic AMP concentration and protein kinase activity was not significantly influenced by fasting and refeeding while fasting decreased the effect of terbutaline upon phosphorylase b kinase. Diaphragm glycogen levels were reduced by more than 50% in rats fasted for 24 hours and were significantly increased upon refeeding compared to fed rats. The results indicate that the nutritional state can modulate the sensitivity of the interconverting system for phosphorylase. It is suggested that this modulation might depend upon fatty acid metabolism.

Animals

Adaptations of glycogen metabolism in rat epididymal adipose tissue during fasting and refeeding.

It is well documented that adipose tissue glycogen content decreases during fasting and increases above control during refeeding. We now present evidence that these fluctuations result from adaptations intrinsic to adipose tissue glycogen metabolism that persist in vitro: in response to insulin (1 milliunit/ml), [3H]glucose incorporation into rat fat pad glycogen was reduced to 10% of control after a 3-day fast; incorporation increased 6-fold over fed control on the 4th day of refeeding following a 3-day fast. We have characterized this adaptation with regard to alterations in glycogen synthase and phosphorylase activity. In addition, we found that incubation of fat pads from fasted rats with insulin (1 milliunit/ml) increased glucose-6-P content, indicating that glucose transport was not the rate-limiting step for glucose incorporation into glycogen in the presence of insulin. In contrast, feeding a fat-free diet resulted in dramatic increases in glycogen content of fat pads without a concomitant increase in glucose incorporation into glycogen in response to insulin (1 milliunit/ml). Thus, fasting and refeeding appeared to alter insulin action on adipose tissue glycogen metabolism more than this dietary manipulation.

Adipose Tissue

Interaction of glucocorticoid and insulin in the responses of rats to starvation-refeeding.

Experiments designed to determine whether the role of glucocorticoid (GC) in the induction of the enzyme overshoot response to starvation-refeeding was direct or permissive through insulin were conducted. Intact, adrenalectomized (ADX), and streptozotocin (STREP) treated rats with or without insulin and/or GC replacements were starved for 48 hours and refed a 65% glucose diet for 48 hours. The typical enzyme overshoot response to starvation-refeeding was observed in the intact rats, ADX rats given GC, STREP rats given insulin and ADX-STREP rats given glucocorticoid plus insulin. No overshoot was observed if glucocorticoid was absent whereas a modest increase in enzyme activity could be observed in insulin deficient rats treated with GC.

Adrenal Glands

Iron therapy and refeeding in experimentally malnourished rats.

1. Rats suffering from protein-energy malnutrition were found to have low serum iron, low PCV, and low hemoglobin concentrations. 2. Oral iron supplement during the refeeding of these animals caused various types of infection, the severity of which was related to the dose given. 3. A close association between high serum iron, low serum transferrin, and high incidence of bacterial infection was found. 4. A high protein diet without any oral iron supplement was found to raise the PCV and hemoglobin concentration to the same levels as a high protein diet containing 65 mg iron/kg body wt/day, although this dose of iron was sufficient to produce infection in the malnourished rats during refeeding. Speculation Iron supplementation during the treatment of children with protein-energy malnutrition may predispose to bacterial infection, the severity of which depends on the dose of iron given.

Animals

Effect of different dietary carbohydrates on some hepatic dehydrogenases and total lipid during starvation and refeeding regimen.

Lipogenic capacity of various dietary carbohydrates starch, glucose sucrose and lactose was tested during ad lib feeding and starvation followed by refeeding. Sucrose was found to have maximal effect on hepatic total lipid and the enzymes in the study followed by glucose and sago while lactose was found to be toxic. Starvation resulted depression in the activities of various enzymes. The enzyme activity inducing effect was again exhibited by sucrose diet during ad lib and restricted refeeding followed by starvation.

Animals

Response of heterogenous rat liver lysosome populations to starvation and refeeding.

Starvation-induced alterations in liver lysosomes and their recovery pattern following refeeding were investigated. Fasting of adult rats for five days caused an increase in 'free' activities of acid hydrolyses in liver homogenates and loss in sedimentation of one of the heterogenous populations of lysosomes that could be isolated by differential centrifugation. Isopycnic sucrose gradient centrifugation revealed a decrease in the median and modal equilibration densities of all the forms of lysosomes in response to the dietary deprivation. Further, starvation also evoked a distinct bimodal distribution in a population that was rich in acid phosphatases, beta-galactosidase and N-acetyl-beta-glucosaminidase. Realimentation of starved animals for 10 days was found to restore the enzyme levels and the sedimentation characteristics to normal profiles.

Acetylglucosaminidase

Refeeding-malaria and hyperferraemia.

During the Central African (Sahelian) drought, attacks of falciparum malaria were common in patients and their relatives shortly after their arrival in a hospital in Eastern Niger. A prospective study of 72 adult patients not admitted for malaria and 109 accompanying relatives was undertaken to investigate this observation. 23 attacks occurred in patients and 51 in relatives, with a peak frequency five days after arrival. On arrival, parasitaemia was low but reached a maximum by five days. Serum-iron and percentage saturation of transferrin were moderately increased initially, rose dramatically within forty-eight hours with near maximum saturation, and were falling by the fifth day. It is suggested that the early hyperferraemia, apparently related to refeeding, led to rapid multiplication of existing parasites and attacks of malaria. The results of experimental malarial infection of Wistar rats, half of which had been given intramuscular iron, supported this hypothesis.

Adult

Starvation suppression and refeeding activation of infection. An ecological necessity?

The hypothesis is advanced that starvation suppresses and refeeding activates certain infections as an essential part of an ecological balance between man, his animals, and his environment. During famine, then, man fails to thrive, but his ultimate extinction is prevented in part by the parallel decline in fecundity of his "micropredators". In times of plenty the parallel increase in the same predators is a check against his excessive multiplication.

Adult

Hepatic synthesis and urinary excretion of alpha2u-globulin by male rats: diurnal rhythm and response to fasting and refeeding.

The urine of sexually mature male rats contains a protein of hepatic origin, alpha2u-globulin, not found in the urine of immature or female rats; output of this protein is greatly reduced by fasting. We have examined the effects of feeding and of fasting for various lengths of time on urinary output and hepatic synthesis of alpha2u-globulin. Rats eating ad libitum showed diurnal rhythms of urinary alpha2u-globulin excretion reaching maxima between 2000 and 0800 hours, thus coinciding with the daily feeding period of the rat. Fasting for 12 hours extinguished this diurnal rhythm. When fasting was prolonged up to 36 hours, urinary excretion of alpha2u-globulin was reduced to very low levels. Hepatic synthesis of alpha2u-globulin under these nutritional conditions was investigated by incubating liver polyribosomes with [3H]leucine and a preparation of soluble enzymes for protein synthesis and separating the labeled alpha2u-globulin peptides by immunoprecipitation followed by electrophoresis on sodium dodecyl sulfate-polyacrylamide gels. By this technique, it was shown that only membrane-bound ribosomes in the livers of mature male rats make this protein. Semi-quantitative measurement suggested that the proportion of liver polyribosomes synthesizing alpha2u-globulin was unchanged after 12 hours of fasting, but was reduced after 24 and 36 hours of fasting. It is proposed that the diurnal rhythm in alpha2u-globulin output in the urine represents translational control of its synthesis in the liver, whereas the more extensive reduction with prolonged fasting is partly due to a selective reduction in transcription of the messenger RNA for this protein.

Alpha-Globulins