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1.
Animal ; 15(1): 100009, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33516006

RESUMO

Compensatory growth (CG) is a naturally accelerated growth which occurs upon realimentation, following a prior period of dietary restriction. The process is harnessed worldwide as a management practice to reduce feed costs in beef cattle production. The objective of this study was to assess the potential contribution of hepatic cellular mitochondrial capacity to CG through global hepatic oxidative phosphorylation gene expression analyses as well as functional mitochondrial enzyme activity assays. Holstein-Friesian bulls were separated into two groups: (i) restricted feed allowance for 125 days (Period 1) (RES; n = 30) followed by ad-libitum feeding for 55 days (Period 2) or (ii) ad-libitum access to feed throughout (Periods 1 and 2) (ADLIB; n = 30). At the end of each period, 15 animals from each treatment group were slaughtered and hepatic tissue was collected. Tissue samples were subjected to RNAseq and spectrophotometric analysis for the functional assessment of mitochondria. RES and ADLIB groups grew at 0.6 kg/day and 1.9 kg/day, respectively, during Period 1. During Period 2, the RES group underwent CG growing at 2.5 kg/day, with ADLIB animals gaining 1.4 kg/day. Oxidative phosphorylation genes were differentially expressed in response to both dietary restriction and CG. Spectrophotometric assays indicated that mitochondrial abundance was greater in animals undergoing dietary restriction at the end of Period 1 and subsequently reduced during realimentation (P < 0.02). Results indicate that mitochondrial capacity may be enhanced during dietary restriction to more effectively utilize diet-derived nutrients. However, enhanced mitochondrial capacity does not appear to be directly contributing to CG in cattle.


Assuntos
Privação de Alimentos , Fosforilação Oxidativa , Ração Animal/análise , Animais , Bovinos , Dieta/veterinária , Fígado/metabolismo , Masculino
2.
Bull Entomol Res ; 110(6): 694-699, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32912368

RESUMO

Body size is a trait with many potential impacts on fitness. Adult body size can affect the strength of condition-dependent parental effects that determine offspring phenotypes, with potentially important transgenerational consequences. In a preliminary experiment, larval food deprivation (30 min daily access) created Harmonia axyridis Pallas (Coleoptera: Coccinellidae) females that weighed <50% of controls reared on ad libitum food (eggs of Ephestia kuehniella Zeller). Although only 1/3 of larvae survived to adulthood in the 30 min treatment, adult pairs produced eggs that were not significantly different in size from those of pairs fed ad libitum as larvae. Less extreme larval food deprivation (4 h daily access) was used to create a cohort of H. axyridis that weighed <60% of controls reared on ad libitum food. Small couples had lower 20-day fecundities and reduced egg fertility relative to large couples. Both egg and pupal periods were shortest when both parents were small, and longest when both parents were large, with reciprocal crosses intermediate. There were no consistent effects of parental body size on larval development time, but the progeny of small females mated to large males pupated later than other treatments. Progeny of large pairs had the heaviest adult weights at emergence, and progeny of small pairs, the lightest, with the progeny of reciprocal crosses intermediate. Small females produced the lightest female offspring, whereas small males sired the lightest male offspring, suggesting stronger responses to epigenetic signals from parents of the same sex. These results indicate that H. axyridis cohorts maturing with abundant food will produce progeny with larger potential body size and fitness, whereas those experiencing food limitation will confer size and fitness limitations to the subsequent generation, with potentially important implications for short-term population dynamics.


Assuntos
Tamanho Corporal , Besouros/crescimento & desenvolvimento , Besouros/fisiologia , Privação de Alimentos , Animais , Feminino , Fertilidade , Larva/crescimento & desenvolvimento , Larva/fisiologia , Masculino , Herança Materna , Mariposas , Óvulo , Herança Paterna , Fenótipo , Reprodução/fisiologia
3.
C R Biol ; 343(1): 89-99, 2020 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-32720491

RESUMO

In the present study we hypothesize that aquaporin 4 (AQP4) expression in the chicken oviduct would change during a pause in egg laying that was induced by fasting. Accordingly, the aim of this investigation was to examine the AQP4 mRNA and protein expression, and immunolocalization in the chicken oviduct during the course of regression. The experiment was carried out on laying hens subjected to a pause in laying that was induced by food deprivation for 5 days. Control hens were fed ad libitum. The birds were sacrificed on day 6 of the experiment and all segments of the oviduct were isolated, including the infundibulum, magnum, isthmus, shell gland, and vagina. Subsequently, the gene and protein expressions of AQP4 in the tissues were tested by real-time PCR and Western blot, respectively. The relative mRNA expression of AQP4 was the highest in the infundibulum and vagina and the lowest, and least detectable, in the magnum. The level of AQP4 protein was the highest in the infundibulum and the lowest in the magnum. Fasting resulted in a decrease of the AQP4 mRNA expression (P<0.001) in the infundibulum, a decrease in protein abundance (P<0.01) in the shell gland, and an increase in protein level (P<0.001) in the vagina. Immunohistochemistry demonstrated tissue- and cell-dependent localization of AQP4 protein in the oviductal wall. The intensity of staining was as follows: the infundibulum > shell gland > vagina ≥ isthmus ≫ magnum. In the control hens, the immunoreactivity for AQP4 in the vagina was similar, whereas in other oviductal segments, the immunoreactivity was stronger when compared with the chickens subjected to a pause in laying. In summary, these findings suggest that the AQP4 is an essential protein involved in the regulation of water transport required to create a proper microenvironment for fertilization and egg formation in the hen oviduct.


Assuntos
Aquaporina 4/metabolismo , Galinhas/fisiologia , Privação de Alimentos , Animais , Galinhas/genética , Feminino , Humanos , Imuno-Histoquímica , Oviductos/fisiologia , Oviposição , RNA Mensageiro/genética
4.
Nature ; 583(7814): 115-121, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32528180

RESUMO

The advent of endothermy, which is achieved through the continuous homeostatic regulation of body temperature and metabolism1,2, is a defining feature of mammalian and avian evolution. However, when challenged by food deprivation or harsh environmental conditions, many mammalian species initiate adaptive energy-conserving survival strategies-including torpor and hibernation-during which their body temperature decreases far below its homeostatic set-point3-5. How homeothermic mammals initiate and regulate these hypothermic states remains largely unknown. Here we show that entry into mouse torpor, a fasting-induced state with a greatly decreased metabolic rate and a body temperature as low as 20 °C6, is regulated by neurons in the medial and lateral preoptic area of the hypothalamus. We show that restimulation of neurons that were activated during a previous bout of torpor is sufficient to initiate the key features of torpor, even in mice that are not calorically restricted. Among these neurons we identify a population of glutamatergic Adcyap1-positive cells, the activity of which accurately determines when mice naturally initiate and exit torpor, and the inhibition of which disrupts the natural process of torpor entry, maintenance and arousal. Taken together, our results reveal a specific neuronal population in the mouse hypothalamus that serves as a core regulator of torpor. This work forms a basis for the future exploration of mechanisms and circuitry that regulate extreme hypothermic and hypometabolic states, and enables genetic access to monitor, initiate, manipulate and study these ancient adaptations of homeotherm biology.


Assuntos
Metabolismo Energético/fisiologia , Hipotálamo/citologia , Vias Neurais/fisiologia , Neurônios/fisiologia , Torpor/fisiologia , Animais , Jejum , Feminino , Privação de Alimentos , Glutamina/metabolismo , Hipotálamo/fisiologia , Masculino , Camundongos , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/metabolismo
5.
Proc Biol Sci ; 287(1929): 20200842, 2020 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-32546100

RESUMO

The emergency life-history stage (ELHS) can be divided into two subcategories that describe distinct, coordinated responses to disease- or non-disease-related physiological challenges. Whether an individual can simultaneously express aspects of both subcategories when faced with multiple challenges is poorly understood. Emergency life-history theory suggests that disease- and non-disease-related responses are coordinated at the level of the whole organism and therefore cannot be expressed simultaneously. However, the reactive scope and physiological regulatory network models suggest that traits can be independently regulated, allowing for components of both disease- and non-disease-related responses to be simultaneously expressed within a single organism. To test these ideas experimentally, we subjected female zebra finches to food deprivation, an immune challenge, both, or neither, and measured a suite of behavioural and physiological traits involved in the ELHS. We examined whether the trait values expressed by birds experiencing simultaneous challenges resembled trait values of birds experiencing a single challenge or if birds could express a mixture of trait values concurrently. We find that birds can respond to simultaneous challenges by regulating components of the behavioural and immune responses independently of one another. Modularity within these physio-behavioural networks adds additional dimensions to how we evaluate the intensity or quality of an ELHS. Whether modularity provides fitness advantages or costs in nature remains to be determined.


Assuntos
Tentilhões/fisiologia , Animais , Corticosterona , Feminino , Privação de Alimentos , Comportamento de Doença , Estágios do Ciclo de Vida , Masculino
6.
Nat Neurosci ; 23(8): 981-991, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32514136

RESUMO

Salient experiences are often relived in the mind. Human neuroimaging studies suggest that such experiences drive activity patterns in visual association cortex that are subsequently reactivated during quiet waking. Nevertheless, the circuit-level consequences of such reactivations remain unclear. Here, we imaged hundreds of neurons in visual association cortex across days as mice learned a visual discrimination task. Distinct patterns of neurons were activated by different visual cues. These same patterns were subsequently reactivated during quiet waking in darkness, with higher reactivation rates during early learning and for food-predicting versus neutral cues. Reactivations involving ensembles of neurons encoding both the food cue and the reward predicted strengthening of next-day functional connectivity of participating neurons, while the converse was observed for reactivations involving ensembles encoding only the food cue. We propose that task-relevant neurons strengthen while task-irrelevant neurons weaken their dialog with the network via participation in distinct flavors of reactivation.


Assuntos
Aprendizagem por Discriminação/fisiologia , Plasticidade Neuronal/fisiologia , Neurônios/fisiologia , Córtex Visual/fisiologia , Percepção Visual/fisiologia , Animais , Sinais (Psicologia) , Alimentos , Privação de Alimentos/fisiologia , Camundongos , Recompensa
7.
Arch Insect Biochem Physiol ; 105(1): e21718, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32515853

RESUMO

The autophagy process involves a series of autophagy-related (Atg) proteins, which are conserved in eukaryotes. ULK1/Atg1-ATG13/Atg13 is the core protein complex for autophagy initiation in response to nutrient and hormone signaling. However, how Atg13 is regulated to participate in autophagy is unclear in insects. Here in Bombyx mori, the variation of BmAtg13 was correlated with autophagy induced by steroid hormone 20-hydroxyecdysone (20E) or starvation. Developmental profiles from feeding to prepupal stage revealed that there were two bands of BmAtg13 protein detected by western blot analysis, therein the upper band was intensively decreased, while the lower band was significantly increased which was in accordance with its mRNA variation; and immunofluorescent staining indicated that BmAtg13 was nucleocytoplasmic translocated during larval-pupal metamorphosis when autophagy was dramatically induced. BmAtg13 knockdown and overexpression both inhibits autophagy. Besides, 20E treatment-induced BmAtg13 gene expression, while blocking 20E signaling transduction by knockdown of BmUsp reduced both gene expression and protein level of BmAtg13. These results reveal that BmAtg13 is required for 20E- and starvation-induced autophagy in B. mori, which provides the foundation for further related studies.


Assuntos
Proteínas Relacionadas à Autofagia/genética , Autofagia/genética , Bombyx/fisiologia , Proteínas de Insetos/genética , Animais , Proteínas Relacionadas à Autofagia/metabolismo , Bombyx/genética , Bombyx/crescimento & desenvolvimento , Ecdisterona/metabolismo , Privação de Alimentos , Proteínas de Insetos/metabolismo , Larva/crescimento & desenvolvimento , Larva/fisiologia , Metamorfose Biológica/fisiologia , Pupa/crescimento & desenvolvimento , Pupa/fisiologia
8.
Sci Rep ; 10(1): 7898, 2020 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-32398716

RESUMO

Aggression plays a crucial role in survival all across the animal kingdom. In this study, we investigate the aggressive behaviour of Drosophila suzukii, a known agricultural pest. Bioassays were performed between same sex pairs and the effect of environmental (food deprivation, sex, age and photophase) and social factors (non-social and social). Initially the inter-male and inter-female aggression was determined ethologically consisting of several behaviour patterns. Two hours starvation period increase locomotor activity of flies, promoting increased aggressive behaviour. Most of the behavioural patterns were common between males and females with a few sex-selective. Number of male encounters was higher in flies held in isolation than in those that had been reared with siblings whereas in case of females, only those that were isolated exhibited increased aggression. Females and males D. suzukii that were 4-day-old were more aggressive. In addition it is found that on the 3rd hour after the beginning of photophase, regardless of age, both males and females rise to high intensity aggression patterns.


Assuntos
Agressão/fisiologia , Drosophila/fisiologia , Meio Ambiente , Comportamento Social , Fatores Etários , Animais , Feminino , Privação de Alimentos/fisiologia , Masculino , Atividade Motora/fisiologia
9.
Am Nat ; 195(5): 868-875, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32364789

RESUMO

Inclusive fitness theory predicts that individuals can increase their indirect fitness by grouping with kin. However, kin grouping also increases competition between kin, which potentially outweighs its benefits. The level of kin competition is contingent on environmental conditions and thus highly variable. Hence, individuals should benefit from plastically adjusting kin discrimination according to the expected level of kin competition. Here, we investigate whether perceived high competition affects juvenile kin-shoaling preferences in the cichlid Pelvicachromis taeniatus. Juveniles were given the choice between two shoals consisting of either kin or nonkin. Levels of perceived competition were manipulated through food limitation in the face of the differential energy expenditure of differently sized fish. The preference to shoal with kin decreased with increasing levels of perceived competition; small food-deprived individuals avoided kin. Shoaling with kin under strong competition may reduce individual indirect fitness. Hence, individuals can likely improve their inclusive fitness by plastically adjusting their kin-grouping preferences.


Assuntos
Ciclídeos/fisiologia , Comportamento Social , Animais , Comportamento Competitivo , Privação de Alimentos , Aptidão Genética , Irmãos
10.
PLoS One ; 15(5): e0232814, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32413044

RESUMO

BACKGROUND: Cervical cancer screening rates are known to be strongly associated with socioeconomic status. Our objective was to assess whether the rate is also associated with an aggregated deprivation marker, defined by the location of family doctors' offices. METHODS: To access this association, we 1) collected data from the claim database of the French Health Insurance Fund about the registered family doctors and their enlisted female patients eligible for cervical screening; 2) carried out a telephone survey with all registered doctors to establish if they were carrying out Pap-smears in their practices; 3) geotracked all the doctors' offices in the smallest existing blocks of socioeconomic homogenous populations (IRIS census units) that were assigned a census derived marker of deprivation, the European Deprivation Index (EDI), and a binary variable of urbanization; and 4) we used a multivariable linear mixed model with IRIS as a random effect. RESULTS: Of 348 eligible doctors, 343 responded to the telephone survey (98.6%) and were included in the analysis, encompassing 88,152 female enlisted patients aged 25-65 years old. In the multivariable analysis (adjusted by the gender of the family doctor, the practice of Pap-smears by the doctor and the urbanization of the office location), the EDI of the doctor's office was strongly associated with the cervical cancer screening participation rate of eligible patients (p<0.001). CONCLUSION: The EDI linked to the location of the family doctor's office seems to be a robust marker to predict female patients' participation in cervical cancer screening.


Assuntos
Detecção Precoce de Câncer , Neoplasias do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/epidemiologia , Adulto , Idoso , Feminino , Privação de Alimentos/fisiologia , Humanos , Seguro Saúde , Entrevistas como Assunto , Masculino , Pessoa de Meia-Idade , Teste de Papanicolaou , Consultórios Médicos , Médicos de Família/estatística & dados numéricos , Classe Social , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/terapia , Esfregaço Vaginal
11.
Gene ; 749: 144712, 2020 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-32360412

RESUMO

The quantitative real-time polymerase chain reaction (qRT-PCR) has rapidly become the most sensitive and accurate method for the quantitative analysis of gene expression. Normalization of gene expression to that of relatively stably expressed housekeeping genes is required to facilitate the study of gene expression and to obtain more accurate RT-PCR data. However, no studies of the stability of expression of housekeeping genes in Lymantria dispar have been reported. In the present study, BestKeeper, GeNorm and NormFinder statistical software was used to evaluate the expression of thirteen candidate reference genes in L. dispar under different conditions. The expression levels of candidate reference genes were determined for two biological factors (developmental stages and tissues) and four abiotic treatments (temperature, insecticide, CO2 and starvation). The results showed that the best candidate reference genes in L. dispar were TUB, AK, RPS15 for developmental stages, RPL32 and GAPDH for tissues, ACTB and EF1-α for CO2 stress, GAPDH and RPL32 for temperature stress, RPS3 and GAPDH for insecticide stress, and GAPDH and RPS3 for starvation stress. In summary, EF1-α and TUB are preferential housekeeping genes in L. dispar under various conditions. These results provide a basis for the further study of functional genes of L. dispar.


Assuntos
Genes de Insetos , Mariposas/genética , Animais , Dióxido de Carbono , Primers do DNA , Privação de Alimentos , Expressão Gênica , Genes Essenciais , Inseticidas , Mariposas/crescimento & desenvolvimento , Mariposas/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Estresse Fisiológico/genética , Temperatura
12.
Integr Comp Biol ; 60(1): 43-56, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32294176

RESUMO

Several species of sacoglossan sea slugs are able to sequester chloroplasts from algae and incorporate them into their cells. However, the ability to maintain functional "stolen" plastids (kleptoplasts) can vary significantly within the Sacoglossa, giving species different capacities to withstand periods of food shortage. The present study provides an insight on the comparative shifts experienced by the lipidome of two sacoglossan sea slug species, Elysia viridis (long-term retention of functional chloroplasts) and Placida dendritica (retention of non-functional chloroplasts). A hydrophilic interaction liquid chromatography-mass spectrometry approach was employed to screen the lipidome of specimens from both species feeding on the macroalga Codium tomentosum and after 1-week of starvation. The lipidome of E. viridis was generally unaffected by the absence of food, while that of P. dendritica varied significantly. The retention of functional chloroplasts by E. viridis cells allows this species to endure periods of food shortage, while in P. dendritica a significant reduction in the amount of main lipids was the consequence of the consumption of its own mass to endure starvation. The large proportion of ether phospholipids (plasmalogens) in both sea slug species suggests that these compounds may play a key role in chloroplast incorporation in sea slug cells and/or be involved in the reduction of the oxidative stress resulting from the presence of kleptoplasts.


Assuntos
Clorófitas/fisiologia , Cloroplastos/metabolismo , Privação de Alimentos , Gastrópodes/metabolismo , Lipidômica , Alga Marinha/fisiologia , Animais , Especificidade da Espécie
13.
Proc Natl Acad Sci U S A ; 117(17): 9630-9641, 2020 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-32295881

RESUMO

Translation depends on messenger RNA (mRNA)-specific initiation, elongation, and termination rates. While translation elongation is well studied in bacteria and yeast, less is known in higher eukaryotes. Here we combined ribosome and transfer RNA (tRNA) profiling to investigate the relations between translation elongation rates, (aminoacyl-) tRNA levels, and codon usage in mammals. We modeled codon-specific ribosome dwell times from ribosome profiling, considering codon pair interactions between ribosome sites. In mouse liver, the model revealed site- and codon-specific dwell times that differed from those in yeast, as well as pairs of adjacent codons in the P and A site that markedly slow down or speed up elongation. While translation efficiencies vary across diurnal time and feeding regimen, codon dwell times were highly stable and conserved in human. Measured tRNA levels correlated with codon usage and several tRNAs showed reduced aminoacylation, which was conserved in fasted mice. Finally, we uncovered that the longest codon dwell times could be explained by aminoacylation levels or high codon usage relative to tRNA abundance.


Assuntos
Privação de Alimentos , Fígado/metabolismo , Aminoacil-RNA de Transferência/metabolismo , Ribossomos , Aminoácidos/metabolismo , Aminoácidos/farmacologia , Ração Animal , Animais , Códon , Regulação da Expressão Gênica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fatores de Tempo
14.
Sci Rep ; 10(1): 5202, 2020 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-32251303

RESUMO

Short-term dietary restriction (DR) may prevent organ damage from ischemic or toxic insults in animals, but clear evidence in humans is missing. While especially intraarterial administration of contrast media represents a cause of hospital-acquired acute kidney injury (AKI), targeted preventive strategies are not available. This trial investigated the feasibility and effectiveness of pre-interventional DR for preventing AKI in patients undergoing percutaneous coronary intervention (PCI). Patients were randomized to receive a formula diet containing 60% of daily energy requirement (DR group) or ad-libitum food during the 4-day-interval before PCI. Primary endpoint was change of serum creatinine 48 h after PCI (Δcreatinine). Further analyses included incidence of AKI and safety evaluation. Δcreatinine post PCI in the DR group vs. the control group did not show any difference (DR: 0.03(-0.15,0.14)mg/dL vs. control: 0.09(-0.03,0.22)mg/dL;p = 0.797). Subgroup analyses revealed a significant beneficial impact of DR in patients that received ≤100 ml of contrast agent (DR n = 26: Δcreatinine -0.03(-0.20,0.08)mg/dL vs. control n = 24: Δcreatinine 0.10(-0.08,0.24)mg/dL; p = 0.041) and in patients with ≤2 risk factors for AKI (DR: n = 27; Δcreatinine -0.01(-0.18,0.07)mg/dL vs. control n = 31: Δcreatinine 0.09(-0.03,0.16)mg/dl; p = 0.030). Although the primary endpoint was not met, the results of this trial suggest a beneficial impact of DR in low-to-moderate risk patients.


Assuntos
Lesão Renal Aguda/prevenção & controle , Alimentos Formulados , Lesão Renal Aguda/sangue , Lesão Renal Aguda/induzido quimicamente , Idoso , Antropometria , Doenças Cardiovasculares/epidemiologia , Comorbidade , Meios de Contraste/efeitos adversos , Creatinina/sangue , Procedimentos Cirúrgicos Eletivos , Ingestão de Energia , Feminino , Privação de Alimentos , Humanos , Masculino , Intervenção Coronária Percutânea , Resultado do Tratamento
15.
PLoS One ; 15(4): e0230289, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32251454

RESUMO

We previously reported that maternal nutrient restriction (NR) inhibited ureteric branching, metanephric growth, and nephrogenesis in the rat. Here we examined whether folic acid, a methyl-group donor, rescues the inhibition of kidney development induced by NR and whether DNA methylation is involved in it. The offspring of dams given food ad libitum (CON) and those subjected to 50% food restriction (NR) were examined. NR significantly reduced ureteric tip number at embryonic day 14, which was attenuated by folic acid supplementation to nutrient restricted dams. At embryonic day 18, glomerular number, kidney weight, and global DNA methylation were reduced by NR, and maternal folic acid supplementation again alleviated them. Among DNA methyltransferases (DNMTs), DNMT1 was strongly expressed at embryonic day 15 in CON but was reduced in NR. In organ culture, an inhibitor of DNA methylation 5-aza-2 '-deoxycytidine as well as medium lacking methyl donors folic acid, choline, and methionine, significantly decreased ureteric tip number and kidney size mimicking the effect of NR. In conclusion, global DNA methylation is necessary for normal kidney development. Folic acid supplementation to nutrient restricted dams alleviated the impaired kidney development and DNA methylation in the offspring.


Assuntos
Metilação de DNA/efeitos dos fármacos , Embrião de Mamíferos , Ácido Fólico/farmacologia , Privação de Alimentos , Rim , Organogênese/efeitos dos fármacos , Ureter , Animais , Embrião de Mamíferos/embriologia , Embrião de Mamíferos/patologia , Rim/embriologia , Rim/patologia , Ratos , Ratos Sprague-Dawley , Ureter/embriologia , Ureter/patologia
16.
J Dairy Sci ; 103(5): 4408-4422, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32113758

RESUMO

A possible driver of feed inefficiency in dairy cows is overconsumption. The objective was therefore to test precision feed restriction as a lever to improve feed efficiency of the least efficient lactating dairy cows. An initial cohort of 68 Holstein lactating cows was monitored from calving to end of ad libitum feeding at 196 ± 16 d in milk, with the last 70 d being used to estimate feed efficiency. For a given expected dry matter (DM) intake (DMI) during ad libitum feeding, offered DMI during restriction was set to observed DMI of the 10% most efficient cows during ad libitum feeding for similar performance. Feed restriction lasted during 92 d, with only the last 70 d being used for data analyses. A single diet was fed during ad libitum and restriction periods, and was based on 64.9% of corn silage and 35.1% of concentrates on a DM basis. Individual DMI, body weight, milk production, milk composition, and body condition score were recorded, as well as methane emissions. Feed efficiency was defined as the repeatable part of the random effect of cow on the intercept in a mixed model predicting DMI with net energy in milk, maintenance and body weight gain and loss within parity, feeding level, and time. Milk energy efficiency was estimated in the same way, predicting net energy in milk instead of DMI. The 15 least efficient cows ate 2.6 kg of DM/d more than the 15 most efficient cows during ad libitum feeding with 2 g/kg of DMI lower methane yield, but similar daily methane emissions. Feed restriction decreased DMI by 2.6 kg of DMI/d for the least efficient cows, which was 1.8 kg of DMI/d more than the most efficient cows, and decreased daily methane emissions by 49.2 g/d for the least efficient cows, which was 22.4 g/d more than the most efficient cows. Feed restriction had no significant effect on milk, body weight, or body weight change. Feed restriction reduced the variability of both milk energy and feed efficiencies, as shown by a decrease of their standard deviation from 0.87 to 0.69 kg of DM/d for feed efficiency and from 1.14 to 0.65 UFL/d for milk energy efficiency. Despite narrow efficiency differences, the most efficient cows during ad libitum feeding remained more efficient during feed restriction (r = 0.46 for feed efficiency and 0.49 for milk energy efficiency). The 2 efficiency groups no longer differed in feed efficiency during precision feed restriction. Precision feed restriction seemed to bring the least efficient cows closer to the most efficient cows and to reduce their methane emissions without impairing their performance.


Assuntos
Dieta/veterinária , Privação de Alimentos , Lactação , Metano/biossíntese , Leite/metabolismo , Ração Animal/análise , Animais , Bovinos , Indústria de Laticínios/métodos , Feminino
17.
Artigo em Inglês | MEDLINE | ID: mdl-32169652

RESUMO

The contribution of individual lipoprotein species to the generation of the adrenal cholesterol pool used for the synthesis of anti-inflammatory glucocorticoid species remains unknown. Here we examined the impact of specific lowering of very low-density lipoprotein (VLDL) and low-density (LDL) levels on adrenal cholesterol and glucocorticoid homeostasis. Hereto, lethally-irradiated hypercholesterolemic apolipoprotein E (APOE) knockout mice received APOE-containing bone marrow from wild-type mice (n = 6) or APOE knockout control bone marrow (n = 10) and were subsequently fed a regular chow diet. Transplantation with wild-type bone marrow was associated with a 10-fold decrease in VLDL/LDL-cholesterol levels. No changes were observed in adrenal weights, adrenal cholesterol content, or basal plasma corticosterone levels. However, food deprivation-induced corticosterone secretion was 64% lower (P < 0.05) in wild-type bone marrow recipients as compared to APOE knockout bone marrow recipients, in the context of similar plasma adrenocorticotropic hormone (ACTH) levels. A parallel 19-29% decrease in adrenal relative mRNA expression levels of ACTH-responsive genes SR-BI (P < 0.01), STAR (P < 0.05), and CYP11A1 (P < 0.05) was detected. In support of relative glucocorticoid insufficiency, blood lymphocyte and eosinophil concentrations were respectively 2.4-fold (P < 0.01) and 8-fold (P < 0.001) higher in wild-type bone marrow recipients under food deprivation stress conditions. In conclusion, we have shown that a selective lowering of VLDL/LDL levels in APOE knockout mice through a transplantation with APOE-containing wild-type bone marrow is associated with a decreased maximal adrenal glucocorticoid output. Our studies provide experimental support for the hypothesis that, in vivo, VLDL/LDL serves as the primary source of cholesterol used for glucocorticoid synthesis during food deprivation stress.


Assuntos
Glândulas Suprarrenais/metabolismo , Colesterol/metabolismo , Privação de Alimentos , Glucocorticoides/metabolismo , Hipercolesterolemia/metabolismo , Lipoproteínas VLDL/metabolismo , Animais , Apolipoproteínas E/genética , Células Cultivadas , Masculino , Camundongos , Camundongos Endogâmicos C57BL
18.
Am J Physiol Regul Integr Comp Physiol ; 318(4): R691-R700, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32073900

RESUMO

The free fatty acid receptor 3 (FFA3) is a nutrient sensor of gut microbiota-generated nutrients, the short-chain fatty acids. Previously, we have shown that FFA3 is expressed in ß-cells and inhibits islet insulin secretion ex vivo. Here, we determined the physiological relevance of the above observation by challenging wild-type (WT) and FFA3 knockout (KO) male mice with 1) hyperglycemia and monitoring insulin response via highly sensitive hyperglycemic clamps, 2) dietary high fat (HF), and 3) chemical-induced diabetes. As expected, FFA3 KO mice exhibited significantly higher insulin secretion and glucose infusion rate in hyperglycemic clamps. Predictably, under metabolic stress induced by HF-diet feeding, FFA3 KO mice exhibited less glucose intolerance compared with the WT mice. Moreover, similar islet architecture and ß-cell area in HF diet-fed FFA3 KO and WT mice was observed. Upon challenge with streptozotocin (STZ), FFA3 KO mice initially exhibited a tendency for an accelerated incidence of diabetes compared with the WT mice. However, this difference was not maintained. Similar glycemia and ß-cell mass loss was observed in both genotypes 10 days post-STZ challenge. Higher resistance to STZ-induced diabetes in WT mice could be due to higher basal islet autophagy. However, this difference was not protective because in response to STZ, similar autophagy induction was observed in both WT and FFA3 KO islets. These data demonstrate that FFA3 plays a role in modulating insulin secretion and ß-cell response to stressors. The ß-cell FFA3 and autophagy link warrant further research.


Assuntos
Diabetes Mellitus Experimental/metabolismo , Dieta Hiperlipídica/efeitos adversos , Células Secretoras de Insulina/efeitos dos fármacos , Receptores Acoplados a Proteínas-G/metabolismo , Animais , Apoptose , Autofagia , Glicemia , Proliferação de Células , Privação de Alimentos , Regulação da Expressão Gênica/efeitos dos fármacos , Genótipo , Técnica Clamp de Glucose , Teste de Tolerância a Glucose , Resistência à Insulina , Células Secretoras de Insulina/fisiologia , Masculino , Camundongos , Receptores Acoplados a Proteínas-G/genética
19.
Artigo em Inglês | MEDLINE | ID: mdl-32075001

RESUMO

Although most countries banned manufacturing of polychlorinated biphenyls (PCBs) over 40 years ago, PCBs remain a global concern for wildlife and human health due to high bioaccumulation and biopersistance. PCB uptake mechanisms have been well studied in many taxa; however, less is known about depuration rates and how post-exposure diet can influence PCB concentrations and immune response in fish and wildlife populations. In a controlled laboratory environment, we investigated the influence of subchronic dietary exposure to two PCB Aroclors and food deprivation on tissue-specific concentrations of total PCBs and PCB homologs and innate immune function in channel catfish (Ictalurus punctatus). Overall, we found that the concentration of total PCBs and PCB homologs measured in whole body, fillet, and liver tissues declined more slowly in food-deprived fish, with slowest depuration observed in the liver. Additionally, fish that were exposed to PCBs had lower plasma cortisol concentrations, reduced phagocytic oxidative burst activity, and lower cytotoxic activity, suggesting that PCBs can influence stress and immune responses. However, for most measures of immune function, the effects of food deprivation had a larger effect on immune response than did PCB exposure. Taken together, these results suggest that short-term dietary exposure to PCBs can increase toxicity of consumable fish tissues for several weeks, and that PCB mixtures modulate immune and stress responses via multiple pathways. These results may inform development of human consumption advisories and can help predict and understand the influence of PCBs on fish health.


Assuntos
Arocloros , Exposição Dietética , Ictaluridae , Imunomodulação , Bifenilos Policlorados , Animais , Arocloros/farmacocinética , Arocloros/toxicidade , Privação de Alimentos , Humanos , Imunomodulação/efeitos dos fármacos , Bifenilos Policlorados/farmacocinética , Bifenilos Policlorados/toxicidade , Distribuição Tecidual
20.
Poult Sci ; 99(2): 1010-1018, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32036958

RESUMO

We studied the effects of restricting the access to feed on the anticipatory eating behavior, growth performance, and the development of the proximal part of the gastrointestinal tract (GIT) in broilers. The experiment consisted in physical restriction of the access of broilers to feed for 0, 4, 6, or 8 h per day from 7 to 19 D of age. At 10, 13, 16, and 19 D of age, immediately before the start of the feed restriction (FR) period, 2 birds per cage were euthanized to evaluate crop and gizzard development. The experimental design was completely randomized, and the linear (L) and quadratic (Q) effects of fasting length on growth performance and GIT traits were determined. In addition, the effect of broiler age on GIT development was studied. From 7 to 19 D of age, ADFI (L, Q; P ≤ 0.05) and BW gain (L; P ≤ 0.01) decreased as the length of the FR period increased, with most of the differences observed with 6 or more hours of fasting. However, feed conversion ratio was not affected by FR length. The relative weight of the crop (% BW) and its fresh content increased (L; P ≤ 0.001) and the moisture of the digesta (%) decreased (L; P ≤ 0.001) as the FR period increased. The DM content (g) of the crop increased with FR, with most of the differences observed with 6 or more hours of fasting (L, Q; P ≤ 0.001). At 19 D of age, the Lactobacillus spp. count in the crop increased (L; P ≤ 0.05) with increase in the FR period. Fasting did not affect any gizzard trait at any age. In summary, physical restriction of the access to feed for 6 h or more reduced BW gain but did not affect feed conversion ratio in broilers from 7 to 19 D of age. Feed restriction for 4 to 8 h stimulated the anticipatory feeding behavior and crop development in broilers.


Assuntos
Galinhas/fisiologia , Papo das Aves/crescimento & desenvolvimento , Comportamento Alimentar , Privação de Alimentos , Moela das Aves/crescimento & desenvolvimento , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Galinhas/crescimento & desenvolvimento , Dieta/veterinária , Distribuição Aleatória , Fatores de Tempo
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