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1.
J Hum Evol ; 179: 103357, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37060623

RESUMO

In the context of the Western European Acheulean Project, this study aims to characterize Acheulean technology in Western Europe through the analysis of handaxes and cleavers from 10 key sites (Britain 4, France 4, and Spain 2) to acquire a regional view of the occupation. The historically different systems used to categorize and analyze the data have made it difficult to compare results. Here we apply a unified and simple method (Western European Acheulean Project) that combines the traditional technological and metrical analysis of assemblages containing handaxes and cleavers with an in-depth geometric morphometric approach using three-dimensional models. This approach allows us to achieve a regional interpretation that identifies innovations through time and shaping strategies across the area. Our findings indicate the existence of two main technological groups in the sampled record: 1) northwestern and central France and Britain, from MIS 17/16 to MIS 11, and 2) Atlantic edge (Atapuerca in Spain and Menez-Dregan in France), from MIS 12/11 to MIS 8. Based on our technological analysis, the shaping of handaxes and cleavers was developed through time as a continuum of accumulative actions, with longer and more complex shaping strategies over time. Shaping technology shows traditions of manufacture over both time and geographical areas, which suggest cultural diffusion. Our geometric morphometric analysis further helped to identify not only general trends but also local adaptations in handaxe forms. Based on our findings, there were no apparent sudden innovations, but rather the application and development of specific techniques to refine size and shape.


Assuntos
Hominidae , Leitura , Animais , Arqueologia , Europa (Continente) , França , Espanha , Tecnologia
2.
Evol Anthropol ; 32(1): 10-25, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36383204

RESUMO

Our understanding of when hominins first reached northern Europe is dependent on a fragmented archaeological and fossil record known from as early as marine isotope stage (MIS) 21 or 25 (c. 840 or 950 thousand years ago [Ka]). This contrasts sharply with southern Europe, where hominin occupation is evidenced from MIS 37 to 45 (c. 1.22 or 1.39 million years ago [Ma]). Northern Europe, however, exhibits climatic, geological, demographic, and historical disadvantages when it comes to preserving fossil and archaeological evidence of early hominin habitation. It is argued here that perceived differences in first occupation timings between the two European regions needs to be revised in light of these factors. To enhance this understanding, optimal linear estimation models are run using data from the current fossil and artefact record. Results suggest northern Europe to have first been occupied as early as 1.16 Ma, or as late as 913 Ka. These timings could represent minimum date expectations and be extended through future archaeological and fossil discoveries.


Assuntos
Hominidae , Animais , Europa (Continente) , Fósseis , Arqueologia
3.
Clin Sci (Lond) ; 136(15): 1117-1137, 2022 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-35852150

RESUMO

Maternal infection during pregnancy increases the offspring risk of developing a variety of neurodevelopmental disorders (NDDs), including schizophrenia. While the mechanisms remain unclear, dysregulation of placental function is implicated. We hypothesised that maternal infection, leading to maternal immune activation and stimulated cytokine production, alters placental and yolk sac amino acid transport, affecting fetal brain development and thus NDD risk. Using a rat model of maternal immune activation induced by the viral mimetic polyinosinic:polycytidylic acid (poly(I:C)), we investigated placental and yolk sac expression of system L amino acid transporter subtypes which transport several essential amino acids including branched-chain amino acids (BCAA), maternal and fetal BCAA concentration, placental 14C-leucine transport activity and associated impacts on fetal growth and development. Poly(I:C) treatment increased acutely maternal IL-6 and TNFα concentration, contrasting with IL-1ß. Transcriptional responses for these pro-inflammatory cytokines were found in placenta and yolk sac following poly(I:C) treatment. Placental and yolk sac weights were reduced by poly(I:C) treatment, yet fetal body weight was unaffected, while fetal brain weight was increased. Maternal plasma BCAA concentration was reduced 24 h post-poly(I:C) treatment, yet placental, but not yolk sac, BCAA concentration was increased. Placental and yolk sac gene expression of Slc7a5, Slc7a8 and Slc43a2 encoding LAT1, LAT2 and LAT4 transporter subtypes, respectively, was altered by poly(I:C) treatment. Placental 14C-leucine transport was significantly reduced 24 h post-treatment, contrasting with a significant increase 6 days following poly(I:C) treatment. Maternal immune activation induces dysregulated placental transport of amino acids affecting fetal brain development, and NDD risk potential in offspring.


Assuntos
Desenvolvimento Fetal , Placenta , Aminoácidos/metabolismo , Animais , Encéfalo/metabolismo , Citocinas/metabolismo , Feminino , Leucina/metabolismo , Leucina/farmacologia , Placenta/metabolismo , Poli I-C/farmacologia , Gravidez , Ratos
4.
J Hum Evol ; 165: 103153, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35299090

RESUMO

Studies of flake tools in the British Lower Paleolithic are rare owing to lower quantities of flake tools than handaxes and the perception that flake tool technology became more important in the succeeding Middle Paleolithic. In Britain, and Europe more broadly, MIS 9 (328-301 ka) has been characterized as a period of technological transition owing to the presence of early prepared core technology and the status of the period as the final interglacial prior to the onset of the Middle Paleolithic. It has been argued that the period demonstrates an increase in both the numbers and importance of flake tools, possibly showing emerging Middle Paleolithic behaviors. This study presents the results of a technological examination of flake tools in Britain during MIS 9, focusing on 25 sites, including 15 assemblages previously recorded as having higher quantities of flake tools. We use these assemblages to assess whether the flake tools of MIS 9 represent a transition toward the technology of the Middle Paleolithic. We consider factors including collection history, site formation, function, reduction, and cultural groups. We argue that in Britain the archaeological record of MIS 9 does not show an increase in the use of flake tools and demonstrates more continuity than change in relation to earlier periods of the Lower Paleolithic. There is a technological background of ad hoc retouch of simple flake tools with occasional evidence of more invasively retouched scrapers. Furthermore, aside from the introduction of Levallois technology, flake tools change little in the Early Middle Paleolithic. These results are contextualized within the broader evidence from Europe and comparisons to the longer sequences at key sites. We conclude that the major changes in technology began between MIS 13 and MIS 11 and these merely became cemented during MIS 9 and the following Middle Paleolithic.


Assuntos
Arqueologia , Hominidae , Animais , Europa (Continente) , Tecnologia , Reino Unido
5.
J Hum Evol ; 162: 103103, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34883259

RESUMO

The establishment of the Acheulean in Europe occurred after MIS 17, but it was after the harsh glaciation of MIS 12 and during the long interglacial of MIS 11 that human occupation of Western Europe became more sustained, with an increased number of sites. Menez-Dregan I (Brittany, France) is one of the key sites in Western Europe that dates from this threshold, with an alternating sequence of 16 occupation levels and four marine deposits, from MIS 12 to 8. The large lithic assemblages of more than 154,000 artifacts from knapping (cores, flakes) and shaping (macrotools and shaping flakes) show the varying use of raw materials and activities at the site through the sequence. This work focuses on the study of the handaxes and cleavers using technological and metrical methods with multivariate analysis, in combination with geometric morphometrics, and places these analyses within the context of other technological changes at the site. Collectively, results show the persistent use through the sequence of the same lithic raw materials and technologies, including fire use and the import of glossy sandstone from 20 km away, but with variation in activities at the site. These findings suggest that Menez-Dregan I shows the development of a specific material culture that reflects the local resources and environment. Results further indicate that the site shows the sustained hominin occupation of the area, despite varying climate and environment, with strong traditions of social learning that were maintained through flexibility of site use, deep understanding of the local territory, and the innovation of new technologies, such as the use of fire. Evidence from the site is placed within the wider context of Europe, and contrasted with areas to the north, such as Britain, where hominin occupation was more sporadic and driven by cyclical climate change.


Assuntos
Arqueologia , Hominidae , Animais , Europa (Continente) , França , Humanos , Tecnologia
6.
Clin Sci (Lond) ; 135(11): 1445-1466, 2021 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-34008846

RESUMO

During Ramadan, many pregnant Muslim women fast between dawn and sunset. Although the impacts of prolonged maternal intermittent fasting (IF) on fetal growth and placental function are under-researched, reported effects include reduced placental weight and birth weight. In the present study, pregnant Wistar rats were used to model repeated cycles of IF on fetal development and placental function and to examine sex-specific effects. In the IF group, food was withdrawn daily from 17:00 to 09:00 over 21 days of gestation, while the control group received food ad libitum. Both groups had free water access. IF dams consumed less food, had significantly reduced weight compared with controls, with reduced plasma glucose and amino acids. Both fetal sexes were significantly lighter in the IF group with reduced fetal plasma amino acids. Placental weights and morphology were unchanged. The profile of placental metabolites was altered in the IF group with sex-specific responses evident. Transplacental flux of 14C-methylaminoisobutyric acid (14C-MeAIB), a system A amino acid transporter substrate, was significantly reduced in both fetal sexes in the IF group. Sodium-dependent 14C-MeAIB uptake into isolated placental plasma membrane vesicles was unchanged. The gene expression of system A transporter Slc38a1, Slc38a2 and Slc38a4 was up-regulated in IF male placentas only. No changes were observed in placental SNAT1 and SNAT2 protein expression. Maternal IF results in detrimental impacts on maternal physiology and fetal development with changes in the placental and fetal metabolite profiles. Reduced placental system A transporter activity may be responsible for fetal growth restriction in both sexes.


Assuntos
Sistema A de Transporte de Aminoácidos/metabolismo , Sistemas de Transporte de Aminoácidos/metabolismo , Jejum , Retardo do Crescimento Fetal/metabolismo , Placenta/metabolismo , Animais , Feminino , Desenvolvimento Fetal/fisiologia , Feto/metabolismo , Gravidez , Ratos Wistar
7.
J Hum Evol ; 156: 103011, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34102521

RESUMO

The period between 600 and 400 ka is a critical phase for human evolution in Europe. The south and northwest saw a dramatic increase in sites, the spread of handaxe technology alongside bone and wooden tool manufacture, efficient hunting techniques, and the use of fire. Lithic assemblages show considerable variation, including the presence/absence of handaxes and tool morphology. To explain this variation, we propose the Cultural Mosaic Model, which suggests that there is a range of expressions of the Acheulean, with local resources being instrumental in creating distinct material cultures with or without handaxes. We argue that if typologically and technologically distinct assemblage types are regionally distributed, chronologically separated, and persistent over time, then they are unlikely to be caused purely by raw material constraints or functional variation but rather reflect populations with different material cultures. We initially assess the model using British data. Britain was a northwestern peninsula of Europe, and oscillations in climate led to episodic occupation. The terraces of the pre-MIS 12 Bytham River provide a framework for dating occupation to MIS 13 and 15, while during MIS 11, archaeological sites with rich environmental records can be dated to substage level. We suggest there are six chronologically and typologically distinct assemblage types that reflect a series of population incursions into Britain. We review the broader European lithic record, which is consistent with the Cultural Mosaic Model. In developing the model, we suggest that during stable climate, localized cultures developed, while climatic change led to shifts in population, with increased knowledge exchange and gene flow. We suggest that group expression through material culture was an important stage in social development by promoting group cohesion, larger group size, better cooperation, improved knowledge transfer, and enabling populations to survive in larger foraging territories in northern Europe.


Assuntos
Arqueologia , Tecnologia/história , Europa (Continente) , Fluxo Gênico , História Antiga , Humanos , Rios
8.
J Hum Evol ; 139: 102735, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32078934

RESUMO

Early Levallois core technology is usually dated in Europe to the end of Marine Isotope Stage (MIS) 9 and particularly from the beginning of MIS 8 to MIS 6. This technology is considered as one of the markers of the transition from lower to Middle Paleolithic or from Mode 2 to Mode 3. Recent discoveries show that some lithic innovations actually appeared earlier in western Europe, from MIS 12 to MIS 9, contemporaneous with changes in subsistence strategies and the first appearance of early Neanderthal anatomical features. Among these discoveries, there is the iconic Levallois core technology. A selection of well-dated assemblages in the United Kingdom, France, and Italy dated from MIS 12 to 9, which include both cores and flakes with Levallois features, has been described and compared with the aim of characterizing this technology. The conclusion supports the interpretation that several technical features may be attributed to a Levallois technology similar to those observed in younger Middle Paleolithic sites, distinct from the main associated core technologies in each level. Some features in the sample of sites suggest a gradual transformation of existing core technologies. The small evidence of Levallois could indicate occasional local innovations from different technological backgrounds and would explain the diversity of Levallois methods that is observed from MIS 12. The technological roots of Levallois technology in the Middle Pleistocene would suggest a multiregional origin and diffusion in Europe and early evidence of regionalization of local traditions through Europe from MIS 12 to 9. The relationships of Levallois technology with new needs and behaviors are discussed, such as flake preference, functional reasons related to hunting and hafting, an increase in the use of mental templates in European populations, and changes in the structure of hominin groups adapting to climatic and environmental changes.


Assuntos
Evolução Biológica , Hominidae , Tecnologia , Animais , Arqueologia , França , Itália , Homem de Neandertal , Reino Unido
9.
J Hum Evol ; 144: 102776, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32505032

RESUMO

Fossil hominin footprints provide a direct source of evidence of locomotor behavior and allow inference of other biological data such as anthropometrics. Many recent comparative analyses of hominin footprints have used 3D analytical methods to assess their morphological affinities, comparing tracks from different locations and/or time periods. However, environmental conditions can sometimes preclude 3D digital capture, as was the case at Happisburgh (England) in 2013. Consequently, we use here a 2D geometric morphometric approach to investigate the evolutionary context of the Happisburgh tracks. The comparative sample of hominin tracks comes from eight localities that span a broad temporal range from the Pliocene to Late Holocene. The results show disparity in the shapes of tracks ascribed to hominins from the Pliocene (presumably Australopithecus afarensis), Pleistocene (presumably Homo erectus and Homo antecessor), and Holocene (Homo sapiens). Three distinct morphological differences are apparent between time samples: changes in adduction of the hallux, changes in the shape and position of the medial longitudinal arch impression, and apparent changes in foot proportions. Linear dimensions classified the potential H. antecessor tracks from Happisburgh as being most similar to the presumed H. erectus prints from Ileret. We demonstrate using 2D geometric morphometric methods and linear dimensions that the Happisburgh tracks are morphologically similar to other presumed Homo tracks and differ from the Laetoli footprints. The probable functional implications of these results fit well with previous comparative analyses of hominin tracks at other sites.


Assuntos
Evolução Biológica , Pé/anatomia & histologia , Fósseis/anatomia & histologia , Hominidae/anatomia & histologia , Animais , Inglaterra , Hallux/anatomia & histologia
10.
Int J Mol Sci ; 21(12)2020 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-32630604

RESUMO

Vascular calcification describes the formation of mineralized tissue within the blood vessel wall, and it is highly associated with increased cardiovascular morbidity and mortality in patients with chronic kidney disease, diabetes, and atherosclerosis. In this article, we briefly review different rodent models used to study vascular calcification in vivo, and critically assess the strengths and weaknesses of the current techniques used to analyze and quantify calcification in these models, namely 2-D histology and the o-cresolphthalein assay. In light of this, we examine X-ray micro-computed tomography (µCT) as an emerging complementary tool for the analysis of vascular calcification in animal models. We demonstrate that this non-destructive technique allows us to simultaneously quantify and localize calcification in an intact vessel in 3-D, and we consider recent advances in µCT sample preparation techniques. This review also discusses the potential to combine 3-D µCT analyses with subsequent 2-D histological, immunohistochemical, and proteomic approaches in correlative microscopy workflows to obtain rich, multifaceted information on calcification volume, calcification load, and signaling mechanisms from within the same arterial segment. In conclusion we briefly discuss the potential use of µCT to visualize and measure vascular calcification in vivo in real-time.


Assuntos
Calcificação Vascular/patologia , Microtomografia por Raio-X/métodos , Microtomografia por Raio-X/tendências , Animais , Aterosclerose/patologia , Humanos , Imageamento Tridimensional/métodos , Microscopia/métodos , Modelos Animais , Proteômica , Insuficiência Renal Crônica/patologia , Calcificação Vascular/diagnóstico por imagem , Calcificação Vascular/metabolismo
11.
Exp Physiol ; 104(3): 421-433, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30575177

RESUMO

NEW FINDINGS: What is the central question of this study? Urotensin II is upregulated in patients in the later stages of chronic kidney disease (CKD), particularly in individuals requiring dialysis. Could treatment with a urotensin II receptor antagonist slow progression of renal disease? What is the main finding and its importance? In the rat, expression of urotensin II and its receptor increased, extending into cortical structures as CKD progressed towards end-stage renal failure. Subchronic treatment with a urotensin receptor antagonist slowed but did not prevent progression of CKD. This suggests that urotensin II contributes to the decline in renal function in CKD. ABSTRACT: Elevated serum and urine urotensin II (UII) concentrations have been reported in patients with end-stage chronic kidney disease (CKD). Similar increases in UII and its receptor, UT, have been reported in animal models of CKD, but only at much earlier stages of renal dysfunction. The aim of this study was to characterize urotensin system expression as renal disease progresses to end-stage failure in a ⅚ subtotal nephrectomy (SNx) rat model. Male Sprague-Dawley rats underwent SNx or sham surgery and were killed at 8 weeks postsurgery [early (E)] or immediately before end-stage renal failure [30 ± 3 weeks postsurgery; late (L)]. Systolic blood pressure, urinary albumin:creatinine ratio and glomerulosclerosis index were all increased in SNx-E rats compared with sham-E by 8 weeks postsurgery. These changes were associated with an increase in renal immunoreactive UII staining but little change in UT expression. As CKD progressed to end-stage disease in the SNx-L group, markers of renal function deteriorated further, in association with a marked increase in immunoreactive UII and UT staining. Subchronic administration of a UT antagonist, SB-611812, at 30 mg kg-1  day-1 for 13 weeks, in a separate group of SNx rats resulted in a 2 week delay in the increase in both systolic blood pressure and urinary albumin:creatinine ratio observed in vehicle-treated SNx but did not prevent the progression of renal dysfunction. The urotensin system is upregulated as renal function deteriorates in the rat; UT antagonism can slow but not prevent disease progression, suggesting that UII plays a role in CKD.


Assuntos
Rim/metabolismo , Insuficiência Renal Crônica/metabolismo , Urotensinas/metabolismo , Animais , Pressão Sanguínea/fisiologia , Progressão da Doença , Taxa de Filtração Glomerular/fisiologia , Masculino , Nefrectomia/métodos , Ratos , Ratos Sprague-Dawley
13.
BMC Pregnancy Childbirth ; 18(1): 421, 2018 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-30359228

RESUMO

BACKGROUND: Although exempt, many pregnant Muslim women partake in the daily fast during daylight hours during the month of Ramadan. In other contexts an impoverished diet during pregnancy impacts on birth weight. The aim of this systematic review was to determine whether Ramadan fasting by pregnant women affects perinatal outcomes. Primary outcomes investigated were perinatal mortality, preterm birth and small for gestational age (SGA) infants. Secondary outcomes investigated were stillbirth, neonatal death, maternal death, hypertensive disorders of pregnancy, gestational diabetes, congenital abnormalities, serious neonatal morbidity, birth weight, preterm birth and placental weight. METHODS: Systematic review and meta-analysis of observational studies and randomised controlled trials was conducted in EMBASE, MEDLINE, CINAHL, Web of Science, Google Scholar, the Health Management Information Consortium and Applied Social Sciences Index and Abstracts. Studies from any year were eligible. Studies reporting predefined perinatal outcomes in pregnancies exposed to Ramadan fasting were included. Cohort studies with no comparator group or that considered fasting outside pregnancy were excluded, as were studies assuming fasting practice based solely upon family name. Quality of included studies was assessed using the ROBINS-I tool for assessing risk of bias in non-randomised studies. Analyses were performed in STATA. RESULTS: From 375 records, 22 studies of 31,374 pregnancies were included, of which 18,920 pregnancies were exposed to Ramadan fasting. Birth weight was reported in 21 studies and was not affected by maternal fasting (standardised mean difference [SMD] 0.03, 95% CI 0.00 to 0.05). Placental weight was significantly lower in fasting mothers (SMD -0.94, 95% CI -0.97 to -0.90), although this observation was dominated by a single large study. No data were presented for perinatal mortality. Ramadan fasting had no effect on preterm delivery (odds ratio 0.99, 95% CI 0.72 to 1.37) based on 5600 pregnancies (1193 exposed to Ramadan fasting). CONCLUSIONS: Ramadan fasting does not adversely affect birth weight although there is insufficient evidence regarding potential effects on other perinatal outcomes. Further studies are needed to accurately determine whether Ramadan fasting is associated with adverse maternal or neonatal outcome.


Assuntos
Jejum/fisiologia , Resultado da Gravidez/epidemiologia , Peso ao Nascer/fisiologia , Feminino , Humanos , Recém-Nascido , Islamismo , Mortalidade Perinatal , Gravidez
14.
Nature ; 466(7303): 229-33, 2010 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-20613840

RESUMO

The dispersal of early humans from Africa by 1.75 Myr ago led to a marked expansion of their range, from the island of Flores in the east to the Iberian peninsula in the west. This range encompassed tropical forest, savannah and Mediterranean habitats, but has hitherto not been demonstrated beyond 45 degrees N. Until recently, early colonization in Europe was thought to be confined to the area south of the Pyrenees and Alps. However, evidence from Pakefield (Suffolk, UK) at approximately 0.7 Myr indicated that humans occupied northern European latitudes when a Mediterranean-type climate prevailed. This provided the basis for an 'ebb and flow' model, where human populations were thought to survive in southern refugia during cold stages, only expanding northwards during fully temperate climates. Here we present new evidence from Happisburgh (Norfolk, UK) demonstrating that Early Pleistocene hominins were present in northern Europe >0.78 Myr ago when they were able to survive at the southern edge of the boreal zone. This has significant implications for our understanding of early human behaviour, adaptation and survival, as well as the tempo and mode of colonization after their first dispersal out of Africa.


Assuntos
Clima , Emigração e Imigração/história , Meio Ambiente , Hominidae , Adaptação Fisiológica , Animais , Arqueologia , Ecossistema , Fósseis , Geografia , Sedimentos Geológicos/química , História Antiga , Humanos , Magnetismo , Paleontologia , Rios , Estações do Ano , Sobrevida , Tecnologia/história , Tecnologia/instrumentação , Temperatura , Reino Unido
15.
Science ; 381(6661): 947-948, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37651523

RESUMO

Genetic analyses suggest an ancient human population crash 900,000 years ago.

16.
Science ; 381(6658): 693-699, 2023 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-37561880

RESUMO

The oldest known hominin remains in Europe [~1.5 to ~1.1 million years ago (Ma)] have been recovered from Iberia, where paleoenvironmental reconstructions have indicated warm and wet interglacials and mild glacials, supporting the view that once established, hominin populations persisted continuously. We report analyses of marine and terrestrial proxies from a deep-sea core on the Portugese margin that show the presence of pronounced millennial-scale climate variability during a glacial period ~1.154 to ~1.123 Ma, culminating in a terminal stadial cooling comparable to the most extreme events of the last 400,000 years. Climate envelope-model simulations reveal a drastic decrease in early hominin habitat suitability around the Mediterranean during the terminal stadial. We suggest that these extreme conditions led to the depopulation of Europe, perhaps lasting for several successive glacial-interglacial cycles.


Assuntos
Hominidae , Animais , Clima , Ecossistema , Temperatura Baixa , Mudança Climática
17.
Clin Sci (Lond) ; 122(6): 281-8, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21966935

RESUMO

Sodium retention has been proposed as the cause of hypertension in the LP rat (offspring exposed to a maternal low-protein diet in utero) model of developmental programming because of increased renal NKCC2 (Na+/K+/2Cl- co-transporter 2) expression. However, we have shown that LP rats excrete more rather than less sodium than controls, leading us to hypothesize that LP rats ingest more salt in order to maintain sodium balance. Rats were fed on either a 9% (low) or 18% (control) protein diet during pregnancy; male and female offspring were studied at 4 weeks of age. LP rats of both sexes held in metabolism cages excreted more sodium and urine than controls. When given water to drink, LP rats drank more and ate more food than controls, hence sodium intake matched excretion. However, when given a choice between saline and water to drink, the total volume of fluid ingested by LP rats fell to control levels, but the volume of saline taken was significantly larger [3.8±0.1 compared with 8.8±1.3 ml/24 h per 100 g of body weight in control and LP rats respectively; P<0.001]. Interestingly food intake also fell to control levels. Total body sodium content and ECF (extracellular fluid) volumes were greater in LP rats. These results show that prenatal programming of renal sodium wasting leads to a compensatory increase in salt appetite in LP rats. We speculate that the need to maintain salt homoeostasis following malnutrition in utero stimulates greater food intake, leading to accelerated growth and raised BP (blood pressure).


Assuntos
Ingestão de Alimentos , Feto/metabolismo , Rim/metabolismo , Cloreto de Sódio na Dieta/administração & dosagem , Sódio/metabolismo , Animais , Dieta com Restrição de Proteínas , Líquido Extracelular/metabolismo , Feminino , Tamanho do Órgão , Ratos , Ratos Wistar , Aumento de Peso
18.
Exp Physiol ; 97(6): 785-95, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22327329

RESUMO

Urotensin II (UII), a peptide hormone which influences glomerular filtration rate and urine concentration, and its receptor, UT, are expressed in the adult rat kidney. The ability of the kidney to reabsorb sodium and water starts to develop in utero and matures during early postnatal life in the rat, yet little is known about the ontogeny of the renal UII system. This study mapped renal expression of the urotensin system during the fetal and postnatal periods and determined renal activity of UII in the immature rat. Urotensin II peptide and mRNA were present in Sprague-Dawley (SD) rat metanephroi from the earliest stage examined, embyonic day 19 (E19; rat gestation 22 days); levels increased to peak at 4 weeks of age. In contrast, UT protein and mRNA expression declined rapidly between E19 and birth and remained at a similar level postnatally. Infusion of rat UII [6-60 pmol min(-1) (100 g body weight)(-1)] or rat urotensin-related peptide [6 pmol min(-1) (100 g body weight)(-1)] in anaesthetized 4-week-old SD rats had no influence on measured renal parameters; however, infusion of UT antagonist, SB-706375 (0.01 mg kg(-1) min(-1)), provoked a pronounced diuresis [vehicle 23.5 ± 1.9 versus antagonist 75.3 ± 12.5 µl min(-1) (100 g body weight)(-1); P < 0.001] and natriuresis, accompanied by modest increases in effective renal blood flow and glomerular filtration rate [vehicle 0.4 ± 0.1 versus antagonist 1.1 ± 0.2 ml min(-1) (100 g body weight)(-1); P < 0.0001] and a significant increase in fractional sodium excretion. These results indicate that the endogenous rat UII system may influence renal sodium and water excretion before the onset of full urine concentrating capacity in the SD rat.


Assuntos
Taxa de Filtração Glomerular/fisiologia , Rim/irrigação sanguínea , Rim/fisiologia , Urotensinas/genética , Urotensinas/metabolismo , Animais , Feminino , Feto/metabolismo , Taxa de Filtração Glomerular/genética , Rim/metabolismo , Masculino , Natriurese/genética , Natriurese/fisiologia , Hormônios Peptídicos/genética , Hormônios Peptídicos/metabolismo , RNA Mensageiro/genética , Ratos , Ratos Sprague-Dawley , Fluxo Sanguíneo Regional/genética , Fluxo Sanguíneo Regional/fisiologia , Sódio/metabolismo , Urotensinas/antagonistas & inibidores , Água/metabolismo
19.
Pediatr Nephrol ; 27(2): 285-93, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21863227

RESUMO

Hypertension and renal dysfunction can be programmed in the rat by prenatal exposure to a low-protein (LP) diet. Expression of the renal thick ascending limb (TAL) sodium transporter NKCC2 is up-regulated, which has been predicted to result in greater sodium reabsorption. However, we have shown that LP rats excrete more not less sodium. The aim of this study was to determine whether the increased abundance of sodium:potassium:chloride (Na(+):K(+):2Cl(-)) co-transporter (NKCC2) leads to enhanced sodium uptake by the TAL. Pregnant Wistar rats were fed a control (18%) or LP (9%) diet. Amiloride (AM), bendroflumethiazide (BF), and furosemide (FUR) were administered acutely to male offspring at 4 weeks of age. Fractional excretion of sodium (FE(Na)) was significantly greater in vehicle-infused LP rats (3.0 ± 0.3%) compared with controls (1.7 ± 0.5, P < 0.01). FE(Na) by the LP proximal tubule did not differ from controls, whereas FE(Na) by the distal tubule was significantly greater (P < 0.01). These differences were abolished by the administration of AM + BF (equivalent to the outflow from the TAL) and AM + BF + FUR (equivalent to the outflow from the proximal tubule), suggesting that the increase in NKCC2 expression was not functional. However, during acute salt loading, the LP rat pressure natriuresis curve was shifted rightward, implying that raised systemic blood pressure is required to match urinary sodium excretion with dietary intake. These data suggest that renal sodium handling is impaired in the LP rat but that this is not due to increased NKCC2 expression.


Assuntos
Feto/fisiologia , Hipertensão/metabolismo , Túbulos Renais/metabolismo , Sódio/metabolismo , Absorção , Animais , Dieta com Restrição de Proteínas , Diurese , Feminino , Masculino , Natriurese , Gravidez , Ratos , Ratos Wistar , Simportadores de Cloreto de Sódio-Potássio/fisiologia , Membro 1 da Família 12 de Carreador de Soluto
20.
PLoS One ; 17(3): e0258372, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35271586

RESUMO

Pregnant Muslim women are exempt from fasting during Ramadan; however a majority are reported to fast. The impact of this form of maternal intermittent fasting (IF) on fetal development and offspring health is not well defined. Using a rat model, we have shown previously that maternal IF results in fetal growth restriction accompanied by changes in placental nutrient transport function. The aim of this study was to assess cardiovascular, metabolic and renal function in adult offspring of IF-exposed dams. Food was withheld from Wistar rats from 17:00 to 09:00 daily throughout pregnancy; controls had ad libitum access to food. Birth weight was unaffected; however male IF pups grew more slowly up to 10 weeks of age (P < 0.01) whereas IF females matched their control counterparts. Systolic blood pressure (SBP), glucose tolerance and basal renal function at 14 weeks were not affected by IF exposure. When offered saline solutions (0.9-2.1%) to drink, females showed a greater salt preference than males (P < 0.01); however there were no differences between dietary groups. A separate group of pups was weaned onto a 4% NaCl diet. SBP increased in IF pups sooner, at 7 weeks (P < 0.01), than controls which became hypertensive from 10 weeks. Renal function did not appear to differ; however markers of renal injury were elevated in IF males (P < 0.05). Maternal IF does not affect resting cardiovascular, metabolic and renal function; but when challenged by dietary salt load male IF offspring are more prone to renal injury.


Assuntos
Jejum , Efeitos Tardios da Exposição Pré-Natal , Filhos Adultos , Animais , Feminino , Humanos , Rim/fisiologia , Masculino , Placenta/metabolismo , Gravidez , Efeitos Tardios da Exposição Pré-Natal/metabolismo , Ratos , Ratos Wistar , Cloreto de Sódio na Dieta/metabolismo
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