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1.
J Asthma ; 60(10): 1907-1917, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37021838

RESUMO

OBJECTIVE: Asthma occurs in ∼17% of Australian pregnancies and is associated with adverse perinatal outcomes, which worsen with poor asthma control. Consequently, the South Australian 'Asthma in Pregnancy' perinatal guidelines were revised in 2012 to address management according to severity. This study investigated if these revised guidelines reduced the impact of maternal asthma on risks of adverse perinatal outcomes before (Epoch 1, 2006-2011) and after the revision (Epoch 2, 2013-2018). METHODS: Routinely collected perinatal and neonatal datasets from the Women's and Children's Hospital (Adelaide, Australia) were linked. Maternal asthma (prevalence:7.5%) was defined as asthma medication use or symptoms described to midwives. In imputation (n = 59131) and complete case datasets (n = 49594), analyses were conducted by inverse proportional weighting and multivariate logistic regression, accounting for confounders. RESULTS: Overall, maternal asthma was associated with increased risks of any antenatal corticosteroid treatment for threatened preterm birth (aOR 1.319, 95% CI 1.078-1.614), any Cesarean section (aOR 1.196, 95% CI 1.059-1.351), Cesarean section without labor (aOR 1.241, 95% CI 1.067-1.444), intrauterine growth restriction (IUGR, aOR 1.285, 95% CI 1.026-1.61), and small for gestational age (aOR 1.324, 95% CI 1.136-1.542). After guideline revision, asthma-associated risks of any Cesarean section (p < 0.001), any antenatal corticosteroids (p = 0.041), and small for gestational age (p = 0.050), but not IUGR and Cesarean section without labor, were reduced. CONCLUSIONS: Clinical practice guidelines based on the latest evidence do not guarantee clinical efficacy. Since adverse perinatal outcomes did not all improve, this work highlights the need to evaluate the ongoing impact of guidelines on clinical outcomes.


Assuntos
Asma , Complicações na Gravidez , Nascimento Prematuro , Criança , Gravidez , Feminino , Recém-Nascido , Humanos , Resultado da Gravidez/epidemiologia , Complicações na Gravidez/tratamento farmacológico , Complicações na Gravidez/epidemiologia , Cesárea , Estudos Retrospectivos , Nascimento Prematuro/epidemiologia , Asma/tratamento farmacológico , Asma/epidemiologia , Asma/complicações , Austrália
2.
Diabetes Obes Metab ; 15(7): 660-7, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23402546

RESUMO

AIM: The aim of the study is to compare the effects of metformin and insulin treatment for gestational diabetes mellitus (GDM) on vitamin B12 and homocysteine (Hcy) status. METHODS: Women with GDM, who met criteria for insulin treatment, were randomly assigned to metformin (n = 89) or insulin (n = 91) in the Adelaide cohort of the metformin in gestational diabetes (MiG) trial. Fasting serum total vitamin B12 (TB12), holotranscobalamin (HoloTC), a marker of functional B12 status and plasma Hcy concentrations were measured at 20-34 weeks (at randomization) and 36 weeks gestation, then at 6-8 weeks postpartum. RESULTS: Circulating TB12, HoloTC and Hcy were similar in both treatment groups at each time point. Women who were taking dietary folate supplements at randomization had higher serum TB12 and HoloTC at randomization than those not taking folate. Overall, serum TB12 fell more between randomization and 36 weeks gestation in the metformin group than in the insulin group (metformin: -19.7 ± 4.7 pmol/l, insulin: -6.4 ± 3.6 pmol/l, p = 0.004). The decrease in serum TB12 during treatment was greater with increasing treatment duration in metformin-treated (p < 0.001), but not in insulin-treated women. CONCLUSIONS: Total, but not bioavailable, vitamin B12 stores were depleted during pregnancy to a greater extent in metformin-treated than in insulin-treated women with GDM, but neither analyte differed between groups at any stage. This adds further evidence supporting metformin as a safe alternative treatment to insulin in GDM. Further investigation is needed to evaluate whether women treated with metformin for longer periods in pregnancy require additional B12 or other supplementation.


Assuntos
Diabetes Gestacional/tratamento farmacológico , Hiper-Homocisteinemia/induzido quimicamente , Hipoglicemiantes/efeitos adversos , Insulina/efeitos adversos , Metformina/efeitos adversos , Estado Nutricional/efeitos dos fármacos , Deficiência de Vitamina B 12/induzido quimicamente , Adulto , Biomarcadores/sangue , Estudos de Coortes , Diabetes Gestacional/sangue , Feminino , Homocisteína/sangue , Humanos , Hipoglicemiantes/uso terapêutico , Insulina/uso terapêutico , Metformina/uso terapêutico , Período Pós-Parto , Gravidez , Complicações na Gravidez/induzido quimicamente , Segundo Trimestre da Gravidez , Terceiro Trimestre da Gravidez , Austrália do Sul , Transcobalaminas/análise , Vitamina B 12/sangue
3.
Reprod Fertil Dev ; 25(8): 1216-23, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23257568

RESUMO

Inclusion of high levels of the high-fibre ingredient sugar-beet pulp in pre-mating diets has been shown to increase gonadotrophin concentrations and improve oocyte quality in nulliparous pigs (gilts). This study evaluated the effects of two alternative fibre sources on reproductive performance in gilts. Gilts received one of three diets from 3 weeks before puberty stimulation until Day 19 of the first oestrous cycle: control (39 g kg⁻¹ fibre), bran (500 g kg⁻¹ wheat bran, 65 g kg⁻¹ fibre) or lupin (350 g kg⁻¹ lupin, 118 g kg⁻¹ crude fibre). Diet did not affect circulating LH concentrations or ovarian follicle size. However, a higher percentage of oocytes collected from lupin-supplemented gilts reached metaphase II in vitro compared with those collected from bran-fed or control gilts (89±5% versus 72±5% and 66±5%, respectively; P<0.05). Furthermore, in a second experiment, gilts fed the same lupin-based diet before mating had improved embryo survival (92±5%) on Day 28 after mating compared with control gilts (76±4%; P<0.05). Therefore, feeding a high-fibre diet before mating can improve oocyte quality in gilts without changes in circulating LH, but this effect is dependent on the fibre source.


Assuntos
Fibras na Dieta , Ectogênese , Técnicas de Maturação in Vitro de Oócitos/veterinária , Lupinus/química , Fenômenos Fisiológicos da Nutrição Materna , Oogênese , Sus scrofa/fisiologia , Matadouros , Animais , Cruzamentos Genéticos , Fibras na Dieta/uso terapêutico , Técnicas de Cultura Embrionária/veterinária , Feminino , Desenvolvimento Fetal , Reabsorção do Feto/prevenção & controle , Inseminação Artificial/veterinária , Oócitos/citologia , Gravidez , Desenvolvimento Sexual , Austrália do Sul , Sus scrofa/crescimento & desenvolvimento , Suínos , Doenças dos Suínos/prevenção & controle , Triticum/química
4.
Anim Reprod Sci ; 198: 160-166, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30293744

RESUMO

Selection of sows for large litter size has adverse consequences including lesser and more variable birth weights, reduced piglet viability and greater peri- and post-natal piglet mortality. One approach to improve survival might be to feed caffeine to the sow, which improves piglet viability after induced farrowing, but has not been evaluated in sows which farrow naturally. Large White x Landrace sows were fed 0 (CON: n = 30) or 6 g/day caffeine (CAF: n = 34) with their daily feed from 3 days before expected parturition until farrowing. Numbers of piglets born alive and stillborn, as well as piglet vitality and meconium staining score were recorded at birth. Piglet rectal temperature was measured at 3 and 24 h and piglet survival was recorded through lactation. Compared with CON animals, sows of the CAF group had longer gestations (CON: 115.6 ± 0.3 days; CAF: 116.6 ± 0.3 days, P = 0.01) and piglets of CAF sows had greater rectal temperatures 3 h after birth (CON: 37.6 ± 0.2 °C, CAF 38.0 ± 0.2 °C, P<0.05). Although there was no difference in the stillborn numbers per litter fewer CAF sows delivered stillborn piglets when compared to CON sows (CON: 43.3%, CAF: 20.6%, P = 0.05). Piglet survival to day 18 of lactation was not altered by treatment (CON: 90.4 ± 3.2%, CAF: 92.0 ± 2.4%, P>0.05). The current data suggest that maternal supplementation with caffeine is a promising treatment to prevent premature farrowing and increase piglet temperature at birth, and may decrease the incidence of litters with stillborn piglets.


Assuntos
Animais Recém-Nascidos/fisiologia , Temperatura Corporal/efeitos dos fármacos , Cafeína/administração & dosagem , Prenhez , Suínos , Administração Oral , Animais , Peso ao Nascer , Cafeína/farmacologia , Esquema de Medicação , Feminino , Idade Gestacional , Tamanho da Ninhada de Vivíparos , Gravidez , Prenhez/efeitos dos fármacos , Natimorto/veterinária , Fatores de Tempo
5.
J Reprod Immunol ; 123: 88-93, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28760578

RESUMO

Allergy is a chronic disease that can develop as early as infancy, suggesting that early life factors are important in its aetiology. Variable associations between size at birth, a crude marker of the fetal environment, and allergy have been reported in humans and require comprehensive review. Associations between birth weight and allergy are however confounded in humans, and we and others have therefore begun exploring the effects of early life events on allergy in experimental models. In particular, we are using ovine models to investigate whether and how a restricted environment before birth protects against allergy, whether methyl donor availability contributes to allergic protection in IUGR, and why maternal asthma during pregnancy is associated with increased risks of allergic disease in children. We found that experimental intrauterine growth restriction (IUGR) in sheep reduced cutaneous responses to antigens in progeny, despite normal or elevated IgE responses. Furthermore, maternal methyl donor supplementation in late pregnancy partially reversed effects of experimental IUGR, consistent with the proposal that epigenetic pathways underlie some but not all effects of IUGR on allergic susceptibility. Ovine experimental allergic asthma with exacerbations reduces relative fetal size in late gestation, with some changes in immune populations in fetal thymus suggestive of increased activation. Maternal allergic asthma in mice also predisposes progeny to allergy development. In conclusion, these findings in experimental models provide direct evidence that a perturbed environment before birth alters immune system development and postnatal function, and provide opportunities to investigate underlying mechanisms and develop and evaluate interventions.


Assuntos
Aminoácidos/uso terapêutico , Asma/imunologia , Dieta , Retardo do Crescimento Fetal/imunologia , Hipersensibilidade/imunologia , Efeitos Tardios da Exposição Pré-Natal/imunologia , Vitaminas/uso terapêutico , Animais , Asma/dietoterapia , Bovinos , Feminino , Retardo do Crescimento Fetal/dietoterapia , Humanos , Hipersensibilidade/dietoterapia , Exposição Materna/efeitos adversos , Modelos Animais , Gravidez , Efeitos Tardios da Exposição Pré-Natal/dietoterapia , Ovinos
6.
J Dev Orig Health Dis ; 8(3): 357-369, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28382888

RESUMO

Most individuals whose growth was restricted before birth undergo accelerated or catch-up neonatal growth. This is an independent risk factor for later metabolic disease, but the underlying mechanisms are poorly understood. This study aimed to test the hypothesis that natural and experimentally induced in utero growth restriction increase neonatal appetite and milk intake. Control (CON) and placentally restricted (PR) ewes carrying multiple fetuses delivered naturally at term. Outcomes were compared between CON (n=14) and PR (n=12) progeny and within twin lamb pairs. Lamb milk intake and feeding behaviour and ewe milk composition were determined using a modified weigh-suckle-weigh procedure on days 15 and 23. PR lambs tended to have lower birth weights than CON (-15%, P=0.052). Neonatal growth rates were similar in CON and PR, whilst heavier twins grew faster in absolute but not fractional terms than their co-twins. At day 23, milk protein content was higher in PR than CON ewes (P=0.038). At day 15, PR lambs had fewer suckling bouts than CON lambs and in females light twins had more suckling attempts than their heavier co-twins. Birth weight differences between twins positively predicted differences in milk intakes. Lactational constraint and natural prenatal growth restriction in twins may explain the similar milk intakes in CON and PR. Within twin comparisons support the hypothesis that prenatal constraint increases lamb appetite, although this did not increase milk intake. We suggest that future mechanistic studies of catch-up growth be performed in singletons and be powered to assess effects in each sex.


Assuntos
Animais Lactentes/fisiologia , Peso ao Nascer/fisiologia , Comportamento Alimentar/fisiologia , Retardo do Crescimento Fetal/metabolismo , Tamanho da Ninhada de Vivíparos/fisiologia , Placenta/fisiologia , Animais , Animais Recém-Nascidos , Tamanho Corporal/fisiologia , Feminino , Masculino , Leite/fisiologia , Gravidez , Ovinos
7.
J Dev Orig Health Dis ; 8(5): 618-625, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28975880

RESUMO

Low birth weight is associated with increased risk of cardiovascular disease in adulthood. Intrauterine growth restriction (IUGR) hearts have fewer CMs in early postnatal life, which may impair postnatal cardiovascular function and hence, explain increased disease risk, but whether the cardiomyocyte deficit persists to adult life is unknown. We therefore studied the effects of experimentally induced placental restriction (PR) on cardiac outcomes in young adult sheep. Heart size, cardiomyocyte number, nuclearity and size were measured in control (n=5) and PR (n=5) male sheep at 1 year of age. PR lambs were 36% lighter at birth (P=0.007), had 38% faster neonatal relative growth rates (P=0.001) and had 21% lighter heart weights relative to body weight as adults (P=0.024) than control lambs. Cardiomyocyte number, nuclearity and size in the left ventricle did not differ between control and PR adults; hearts of both groups contained cardiomyocytes (CM) with between one and four nuclei. Overall, cardiomyocyte number in the adult left ventricle correlated positively with birth weight but not with adult weight. This study is the first to demonstrate that intrauterine growth directly influences the complement of CM in the adult heart. Cardiomyocyte size was not correlated with cardiomyocyte number or birth weight. Our results suggest that body weight at birth affects lifelong cardiac functional reserve. We hypothesise that decreased cardiomyocyte number of low birth weight individuals may impair their capacity to adapt to additional challenges such as obesity and ageing.


Assuntos
Peso ao Nascer/fisiologia , Miocárdio/patologia , Miócitos Cardíacos/patologia , Fatores Etários , Animais , Contagem de Células/métodos , Tamanho Celular , Feminino , Previsões , Humanos , Masculino , Gravidez , Ovinos
8.
J Endocrinol ; 232(2): 175-187, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27821470

RESUMO

Preterm birth is associated with increased risk of type 2 diabetes (T2D) in adulthood; however, the underlying mechanisms are poorly understood. We therefore investigated the effect of preterm birth at ~0.9 of term after antenatal maternal betamethasone on insulin sensitivity, secretion and key determinants in adulthood, in a clinically relevant animal model. Glucose tolerance and insulin secretion (intravenous glucose tolerance test) and whole-body insulin sensitivity (hyperinsulinaemic euglycaemic clamp) were measured and tissue collected in young adult sheep (14 months old) after epostane-induced preterm (9M, 7F) or term delivery (11M, 6F). Glucose tolerance and disposition, insulin secretion, ß-cell mass and insulin sensitivity did not differ between term and preterm sheep. Hepatic PRKAG2 expression was greater in preterm than in term males (P = 0.028), but did not differ between preterm and term females. In skeletal muscle, SLC2A4 (P = 0.019), PRKAA2 (P = 0.021) and PRKAG2 (P = 0.049) expression was greater in preterm than in term overall and in males, while INSR (P = 0.047) and AKT2 (P = 0.043) expression was greater in preterm than in term males only. Hepatic PRKAG2 expression correlated positively with whole-body insulin sensitivity in males only. Thus, preterm birth at 0.9 of term after betamethasone does not impair insulin sensitivity or secretion in adult sheep, and has sex-specific effects on gene expression of the insulin signalling pathway. Hence, the increased risk of T2D in preterm humans may be due to factors that initiate preterm delivery or in early neonatal exposures, rather than preterm birth per se.


Assuntos
Betametasona/farmacologia , Glicemia/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Resistência à Insulina/fisiologia , Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Nascimento Prematuro , Efeitos Tardios da Exposição Pré-Natal/metabolismo , Animais , Modelos Animais de Doenças , Feminino , Técnica Clamp de Glucose , Células Secretoras de Insulina/efeitos dos fármacos , Masculino , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/metabolismo , Gravidez , Fatores Sexuais , Ovinos , Carneiro Doméstico , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia
9.
J Dev Orig Health Dis ; 7(5): 548-562, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27335275

RESUMO

Intrauterine growth restriction (IUGR) and subsequent neonatal catch-up growth are implicated in the programming of increased appetite, adiposity and cardiometabolic diseases. Guinea pigs provide an alternate small animal model to rodents to investigate mechanisms underlying prenatal programming, being relatively precocial at birth, with smaller litter sizes and undergoing neonatal catch-up growth after IUGR. The current study, therefore, investigated postnatal consequences of spontaneous IUGR due to varying litter size in this species. Size at birth, neonatal, juvenile (post-weaning, 30-60 days) and adolescent (60-90 days) growth, juvenile and adolescent food intake, and body composition of young adults (120 days) were measured in 158 male and female guinea pigs from litter sizes of one to five pups. Compared with singleton pups, birth weight of pups from litters of five was reduced by 38%. Other birth size measures were reduced to lesser degrees with head dimensions being relatively conserved. Pups from larger litters had faster fractional neonatal growth and faster absolute and fractional juvenile growth rates (P<0.005 for all). Relationships of post-weaning growth, feed intakes and adult body composition with size at birth and neonatal growth rate were sex specific, with neonatal growth rates strongly and positively correlated with adiposity in males only. In conclusion, spontaneous IUGR due to large litter sizes in the guinea pig causes many of the programmed sequelae of IUGR reported in other species, including human. This may therefore be a useful model to investigate the mechanisms underpinning perinatal programming of hyperphagia, obesity and longer-term metabolic consequences.

10.
J Dev Orig Health Dis ; 7(5): 525-537, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27335227

RESUMO

Intrauterine growth restriction (IUGR) has adverse effects on metabolic health and early life, whereas physical activity is protective against later development of metabolic disease. Relationships between birth weight and physical activity in humans, and effects of IUGR on voluntary activity in rodents, are mixed and few studies have measured physical activity in a free-ranging environment. We hypothesized that induced restriction of placental growth and function (PR) in sheep would decrease spontaneous ambulatory activity (SAA) in free-ranging adolescent and young adult progeny from multi-fetal pregnancies. To test this hypothesis, we used Global Positioning System watches to continuously record SAA between 1800 and 1200 h the following day, twice during a 16-day recording period, in progeny of control (CON, n=5 males, 9 females) and PR pregnancies (n=9 males, 10 females) as adolescents (30 weeks) and as young adults (43 weeks). PR reduced size at birth overall, but not in survivors included in SAA studies. In adolescents, SAA did not differ between treatments and females were more active than males overall and during the day (each P<0.001). In adults, daytime SAA was greater in PR than CON females (P=0.020), with a similar trend in males (P=0.053) and was greater in females than males (P=0.016). Adult SAA was negatively correlated with birth weight in females only. Contrary to our hypothesis, restricted placental function and small size at birth did not reduce progeny SAA. The mechanisms for increased daytime SAA in adult female PR and low birth weight sheep require further investigation.

11.
J Dev Orig Health Dis ; 7(5): 449-472, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27689313

RESUMO

Epidemiology formed the basis of 'the Barker hypothesis', the concept of 'developmental programming' and today's discipline of the Developmental Origins of Health and Disease (DOHaD). Animal experimentation provided proof of the underlying concepts, and continues to generate knowledge of underlying mechanisms. Interventions in humans, based on DOHaD principles, will be informed by experiments in animals. As knowledge in this discipline has accumulated, from studies of humans and other animals, the complexity of interactions between genome, environment and epigenetics, has been revealed. The vast nature of programming stimuli and breadth of effects is becoming known. As a result of our accumulating knowledge we now appreciate the impact of many variables that contribute to programmed outcomes. To guide further animal research in this field, the Australia and New Zealand DOHaD society (ANZ DOHaD) Animals Models of DOHaD Research Working Group convened at the 2nd Annual ANZ DOHaD Congress in Melbourne, Australia in April 2015. This review summarizes the contributions of animal research to the understanding of DOHaD, and makes recommendations for the design and conduct of animal experiments to maximize relevance, reproducibility and translation of knowledge into improving health and well-being.

12.
J Endocrinol ; 165(3): R1-6, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10828858

RESUMO

Birth weight is a determinant of blood leptin concentrations in adults. Since nutrition during pregnancy can affect birth weight, the hypothesis that feed intake during pregnancy alters leptin expression in progeny was examined. Leptin mRNA was measured in subcutaneous adipose tissue and leptin protein was measuredin blood plasma from 59 day old female pigs whose mothers were fed at the same restricted rate except that half were permitted to consume 35% more feed during the second quarter of pregnancy. Leptin mRNA abundance in adipose tissue (P=0.015) and plasma leptin concentration (P=0.01) were higher in progeny from mothers provided with more feed. Body weight at birth was negatively correlated with the abundance of leptin mRNA in subcutaneous fat at 59 days of age (P=0.01). This study shows for the first time that maternal nutrition during pregnancy programs postnatal leptin expression in offspring.


Assuntos
Fenômenos Fisiológicos da Nutrição Animal , Leptina/metabolismo , Prenhez/fisiologia , Efeitos Tardios da Exposição Pré-Natal , Tecido Adiposo/metabolismo , Animais , Peso ao Nascer/fisiologia , Feminino , Leptina/sangue , Leptina/genética , Gravidez , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa
13.
J Endocrinol ; 173(1): 151-9, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11927394

RESUMO

Poor prenatal growth is associated with limited evidence of GH deficiency in adult humans, which may contribute to their increased risk of cardiovascular and metabolic disease. We therefore examined the effects of placental restriction of fetal growth (PR) on size at birth, neonatal fractional growth rate (FGR) and the circulating GH profile in adolescent and young adult sheep of both sexes. Moderate or severe PR decreased birth size and increased neonatal FGR of weight, crown-rump length and abdominal circumference. In adolescent males, mean and baseline GH concentrations correlated negatively and independently with birth weight and FGR of weight, and mean GH concentrations correlated negatively with current weight. In young adult males, mean GH concentrations correlated negatively and independently with birth shoulder height and FGR of shoulder height whilst, in young adult females, these correlations were positive. This suggests that restricted fetal growth and reduced neonatal growth rate in sheep are followed by elevated circulating GH in adolescent and adult males, but GH deficiency or increased GH clearance in adult females.


Assuntos
Animais Recém-Nascidos/crescimento & desenvolvimento , Hormônio do Crescimento/sangue , Caracteres Sexuais , Maturidade Sexual/fisiologia , Ovinos/crescimento & desenvolvimento , Análise de Variância , Animais , Peso ao Nascer , Peso Corporal , Feminino , Masculino
14.
J Endocrinol ; 152(1): 19-27, 1997 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9014836

RESUMO

Factors contributing to sex differences in the somatotrophic axis were investigated in growing lambs. In the first experiment, circulating patterns of GH in venous blood, pituitary content of GH and GH mRNA, and median eminence (ME) contents of GH-releasing factor (GRF) and somatostatin (SRIF) were characterized in prepubertal ram and ewe lambs which were pair-fed to remove sex differences in feed intake. Mean and baseline plasma GH concentrations, GH pulse amplitude, and integrated plasma GH were greater in ram lambs than in ewe lambs, but GH interpulse interval did not differ between sexes. The pituitary GH content and ME contents of GRF and SRIF were greater in rams than in ewes, but steady-state levels of mRNA for GH in the pituitary gland did not differ between sexes. A second experiment investigated sex effects on the levels of SRIF in hypophysial portal blood, and found that these did not differ between sexes. We concluded that the presence of sexually dimorphic patterns of GH secretion in the growing lamb is independent of feed-intake differences between sexes. The lack of sex differences in circulating patterns of SRIF in portal plasma implies that there may be a difference in GRF secretion which may produce sexually dimorphic patterns of GH secretion in lamb.


Assuntos
Neuropeptídeos/sangue , Caracteres Sexuais , Ovinos/crescimento & desenvolvimento , Animais , Feminino , Hormônio do Crescimento/análise , Hormônio do Crescimento/sangue , Hormônio do Crescimento/genética , Hormônio Liberador de Hormônio do Crescimento/análise , Hormônio Liberador de Hormônio do Crescimento/sangue , Masculino , Eminência Mediana/química , Neuropeptídeos/análise , Hipófise/irrigação sanguínea , Hipófise/química , RNA Mensageiro/análise , Radioimunoensaio , Taxa Secretória , Ovinos/sangue , Somatostatina/sangue
15.
J Endocrinol ; 166(1): 227-34, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10856901

RESUMO

Circulating growth hormone (GH) concentrations increase in pregnancy and administration of GH during early-mid pregnancy increases fetal growth in well-fed pigs. To determine whether increased maternal GH could promote fetal growth when feed availability is restricted, fifteen cross-bred primiparous sows (gilts) were fed at approximately 30% of ad libitum intake, from mating onwards and were injected daily i.m. with recombinant porcine GH (pGH) at doses of 0, 13.4+/-0.3 and 25.6+/-0.5 microg/kg live weight from day 25 to day 51 of pregnancy (term approximately 115 days). Treatment with pGH increased maternal backfat loss between day 25 and day 51 of pregnancy, and increased maternal plasma IGF-I concentrations measured at day 51 of pregnancy. Fetal body weight, length and skull width at day 51 of pregnancy were increased by maternal treatment with pGH. Fetal plasma glucose concentrations were increased and maternal/fetal plasma glucose concentration gradients were decreased by maternal pGH treatment at 13.4, but not 25.6 microg/kg.day. Fetal plasma concentrations of urea were decreased by both levels of pGH treatment. Overall, fetal weight was negatively correlated with fetal plasma concentrations of urea, positively correlated with maternal plasma alpha-amino nitrogen concentrations and unrelated to glucose concentrations in either maternal or fetal plasma. This suggests that the availability of amino acids, not glucose, limits fetal growth in the first half of pregnancy in underfed gilts, and that maternal GH treatment may improve amino acid delivery to the fetus.


Assuntos
Aminoácidos/metabolismo , Desenvolvimento Embrionário e Fetal/efeitos dos fármacos , Hormônio do Crescimento/administração & dosagem , Troca Materno-Fetal , Distúrbios Nutricionais/tratamento farmacológico , Animais , Glicemia/metabolismo , Feminino , Sangue Fetal/metabolismo , Idade Gestacional , Distúrbios Nutricionais/metabolismo , Gravidez , Suínos , Ureia/sangue
16.
J Endocrinol ; 155(1): 47-54, 1997 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9390005

RESUMO

The ontogeny of the IGF endocrine system was investigated in 15 young lambs before and after weaning at 62 days of age. Before weaning, plasma IGF-I concentrations were higher in rams than ewes, and plasma concentrations of IGF-II and IGF-binding protein-3 (IGFBP-3) also tended to be higher in rams than in ewes. Feed intake of ewes and rams was restricted after weaning to remove sex differences in feed intake. Plasma concentrations of IGF-I and IGFBP-3 did not differ between rams and ewes at 100 days of age, but plasma IGF-II was higher in rams than in ewes at this time. Since circulating concentrations of GH were higher in rams than in ewes at 100 days of age, this implies that the restricted feed intake blocked the IGF-I and IGFBP-3 responses to GH. We conclude that sex differences in circulating IGF-I and IGFBP-3 concentrations in the growing lamb alter with age, and are not present when nutrition is restricted.


Assuntos
Fenômenos Fisiológicos da Nutrição Animal , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/sangue , Ovinos/crescimento & desenvolvimento , Ovinos/metabolismo , Somatomedinas/metabolismo , Envelhecimento/metabolismo , Animais , Feminino , Hormônio do Crescimento/sangue , Hormônio do Crescimento/metabolismo , Fator de Crescimento Insulin-Like I/análise , Fator de Crescimento Insulin-Like I/metabolismo , Fator de Crescimento Insulin-Like II/análise , Fator de Crescimento Insulin-Like II/metabolismo , Masculino , Fatores Sexuais , Somatomedinas/análise , Desmame
17.
J Anim Sci ; 77(8): 2098-103, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10461987

RESUMO

Previous studies have reported conflicting data on gender differences in plasma IGF-I in postnatal pigs. There is also debate over the role of IGF-II in regulation of postnatal growth. We have, therefore, determined the concentrations of plasma IGF-I, IGF-II, and IGF-binding protein-3 (IGFBP-3) in boars, barrows, and gilts and related these to postnatal growth characteristics. Plasma concentrations of IGF-I were higher in boars than in gilts or barrows from 13 wk. of age, and plasma IGF-II levels were generally higher in barrows than in boars or gilts. Plasma IGFBP-3 levels were higher in boars than in gilts or barrows at most ages. Between 15 and 23 wk. of age, IGF-I and IGFBP-3, but not IGF-II, were positively associated with growth rate, voluntary feed intake, and gain:feed ratio. Plasma IGF-II, but not IGF-I or IGFBP-3, was positively associated with backfat depth during this period. These results support the hypothesis that circulating IGF-I and IGF-II are regulators of lean and adipose tissue growth, respectively.


Assuntos
Somatomedinas/fisiologia , Suínos/crescimento & desenvolvimento , Envelhecimento/metabolismo , Ração Animal , Animais , Peso Corporal , Feminino , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/sangue , Fator de Crescimento Insulin-Like I/metabolismo , Fator de Crescimento Insulin-Like II/metabolismo , Masculino , Caracteres Sexuais
18.
J Anim Sci ; 82(1): 93-101, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14753352

RESUMO

Treatment of pigs with porcine ST (pST) in early to mid-pregnancy increases body weight and length of their fetuses by mid-pregnancy, but this increased weight may not persist to birth. We investigated the effects of short- (25 d) and long-term (75 d) treatment with pST, and interactions between long-term pST treatment and crude protein content of diet, in restricted-fed gilts. In both experiments, Large White x Landrace gilts were bred at first estrus to Large White x Duroc boars and allowed to farrow naturally. In the first experiment, gilts were fed 1.8 kg/d of a diet containing 13.5 MJ DE/kg of DM and 15.05% CP (as-fed basis) throughout pregnancy, and were injected daily with 0, 2, or 4 mg pST from d 25 to 50 of pregnancy. Maternal treatment with pST from d 25 to 50 of pregnancy did not affect the number of piglets born per litter or progeny size at birth. In the second experiment, gilts were injected daily with 0 or 2 mg of pST and fed 2.2 kg/d of a diet containing 14.5 MJ DE/kg and either (as-fed basis) 16.6% (0.81% lysine) or 22.2% CP (1.16% lysine) from d 25 to 100 of pregnancy. All gilts were then fed 3.0 kg/d of the lower protein diet from d 100 of pregnancy to farrowing. Treatment with 2 mg pST/d from d 25 to 100 of pregnancy increased live weight of all gilts during the treatment period (P = 0.016), but the change in maternal live weight from d 25 to 100 of pregnancy was only increased (P = 0.001) by pST in gilts fed the higher protein diet. Live weight of gilts 1 d after farrowing was increased by pST treatment (P = 0.007), but was not altered by protein content of diet during pregnancy. In gilts fed the lower protein diet, but not in those fed the higher protein diet, pST treatment decreased maternal backfat depth during treatment (P < 0.020) and 1 d after farrowing (P = 0.002). Treatment with pST during pregnancy did not affect the number of piglets born per litter but independently increased body weight by 11.6% (P < 0.001) and length by 3.4% (P = 0.005) of progeny at birth and decreased (P < 0.01) the negative effect of litter size on body weight at birth. We conclude that in feed-restricted gilts, fetal weight gains in response to 25 d of pST treatment before mid-pregnancy are not maintained to term but that treatment with pST during most of pregnancy increases progeny size at birth and reduces maternal constraint of fetal growth.


Assuntos
Peso ao Nascer/efeitos dos fármacos , Proteínas Alimentares/administração & dosagem , Desenvolvimento Embrionário e Fetal/efeitos dos fármacos , Hormônio do Crescimento/farmacologia , Suínos/fisiologia , Ração Animal , Fenômenos Fisiológicos da Nutrição Animal , Animais , Relação Dose-Resposta a Droga , Feminino , Masculino , Gravidez , Distribuição Aleatória , Suínos/embriologia , Fatores de Tempo
19.
J Anim Sci ; 74(6): 1314-25, 1996 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8791204

RESUMO

The effects of sex and age on patterns of circulating somatotropin (ST) concentration and plasma IGF-I, IGF-II, insulin, and IGF binding protein-3 (IGFBP-3) were studied in ram, wether, and ewe lambs (n = 7 or 8) sampled at mean ages of 81 (I1) and 158 d (I2). Between 81 and 158 d of age, rams grew more rapidly than wethers (P < .01), and wethers grew more rapidly than ewes (P < .01). The sex differences in growth were reflected in empty body weight at slaughter: rams > wethers > ewes (P < .05). Mean plasma ST concentrations, ST pulse amplitude, and integrated plasma ST concentrations were greater (P < .05) in rams than in ewes at I1 and I2. Characteristics of the ST plasma profile in wethers were generally intermediate between those of rams and ewes. The interpulse interval was greater in ewes than in wethers at I2. The IGF-I and IGFBP-3 concentrations were greater in rams than in ewes at both sampling times. Plasma IGF-II was greater in ewes than in rams at I2. Mean plasma ST was approximately two thirds less at I2 than at I1 regardless of sex. Mean plasma ST and IGF-I at both ages were positively correlated with growth. Mean plasma ST at I2 was negatively correlated with fatness at slaughter. Sex and age significantly affected patterns of circulating ST and concentrations of IGF-I and IGFBP-3 in prepubertal growing lambs, under conditions for which growth rates and composition were also sexually dimorphic.


Assuntos
Hormônio do Crescimento/sangue , Proteínas de Ligação a Fator de Crescimento Semelhante a Insulina/sangue , Fator de Crescimento Insulin-Like II/análise , Fator de Crescimento Insulin-Like I/análise , Insulina/sangue , Caracteres Sexuais , Ovinos/sangue , Envelhecimento/sangue , Envelhecimento/fisiologia , Animais , Composição Corporal/fisiologia , Feminino , Modelos Lineares , Masculino , Carne/normas , Ovinos/crescimento & desenvolvimento , Ovinos/fisiologia
20.
Endocr Connect ; 3(3): 138-49, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25117571

RESUMO

Circulating IGFs are important regulators of prenatal and postnatal growth, and of metabolism and pregnancy, and change with sex, age and pregnancy. Single-nucleotide polymorphisms (SNPs) in genes coding for these hormones associate with circulating abundance of IGF1 and IGF2 in non-pregnant adults and children, but whether this occurs in pregnancy is unknown. We therefore investigated associations of plasma IGF1 and IGF2 with age and genotype at candidate SNPs previously associated with circulating IGF1, IGF2 or methylation of the INS-IGF2-H19 locus in men (n=134), non-pregnant women (n=74) and women at 15 weeks of gestation (n=98). Plasma IGF1 concentrations decreased with age (P<0.001) and plasma IGF1 and IGF2 concentrations were lower in pregnant women than in non-pregnant women or men (each P<0.001). SNP genotypes in the INS-IGF2-H19 locus were associated with plasma IGF1 (IGF2 rs680, IGF2 rs1004446 and IGF2 rs3741204) and IGF2 (IGF2 rs1004446, IGF2 rs3741204 and H19 rs217727). In single SNP models, effects of IGF2 rs680 were similar between groups, with higher plasma IGF1 concentrations in individuals with the GG genotype when compared with GA (P=0.016), or combined GA and AA genotypes (P=0.003). SNPs in the IGF2 gene associated with IGF1 or IGF2 were in linkage disequilibrium, hence these associations could reflect other genotype variations within this region or be due to changes in INS-IGF2-H19 methylation previously associated with some of these variants. As IGF1 in early pregnancy promotes placental differentiation and function, lower IGF1 concentrations in pregnant women carrying IGF2 rs680 A alleles may affect placental development and/or risk of pregnancy complications.

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