Effect of breed, age, season and region on sperm morphology in 11,387 bulls submitted to breeding soundness evaluation in Australia.

This study reports the distribution of sperm morphology defects by breed, age, season and region of 11,387 bulls in 500 herds in Australia and near Pacific Islands during annual BBSE. Bull location was divided into 4 broad climatic regions based upon temperature, vegetation and climatic risk. Taking into account the impact of age, season, region, and breed there were differences between breeds in both percent morphologically normal sperm and in some individual categories of sperm abnormality (P < 0.001). Independent of breed, season and region, proximal droplets were significantly increased in bulls less than 20 months of age. This is the first study to comprehensively collect data from this wide geographical area and compare sperm morphology profiles among the Bos indicus and Bos taurus breeds. The findings of this study will act as a guide for veterinary practitioners and cattle breeders in the proportion of bulls that can be expected to pass the PNS test, by breed, age and region, based on a robust data set.

Nutritional Models of Type 2 Diabetes Mellitus.

In order to better understand the events that precede and precipitate the onset of type 2 diabetes (T2DM), several nutritional animal models have been developed. These models are generated by manipulating the diet of either the animal itself, or its mother during her pregnancy, and in comparison to traditional genetic and knock out models, have the advantage that they more accurately reflect the etiology of human T2DM. This chapter will discuss some of the most widely used nutritional models of T2DM: Diet-induced obesity (DIO) in adult rodents, and studies of offspring of mothers fed a low-protein, high-fat and/or high-sugar diet during pregnancy and/or lactation. Several common mechanisms have been identified through which these nutritional manipulations can lead to metabolic disease, including pancreatic beta-cell dysfunction, impaired insulin signaling in skeletal muscle, and the excess accumulation of visceral adipose tissue and consequent deposition of nonesterified fatty acids in peripheral tissues. In addition, there is an emerging concept that obesity/poor quality diets result in increased production and release of pro-inflammatory cytokines from adipose tissue leading to a state of chronic low-grade inflammation, and that this is likely to represent an important link between obesity/diet and metabolic dysfunction. The following chapter will discuss the most common nutritional models of T2DM in experimental animals, their application, and relationship to human etiology, and will highlight the important insights these models have provided into the pathogenesis of T2DM.

Radiographic patterns of muscle involvement in the idiopathic inflammatory myopathies.

INTRODUCTION: This study assesses the burden, distribution, and evolution of muscle inflammation and damage on MRI among subtypes of idiopathic inflammatory myopathy (IIM). METHODS: Musculoskeletal MRIs performed in 66 patients with IIM and 10 patients with non-IIM between 2009 and 2016 were retrospectively graded for muscle edema, fatty replacement (FR), and atrophy. RESULTS: Immune-mediated necrotizing myopathy (IMNM) patients had severe and extensive lower limb muscle edema, FR, and atrophy. The pelvic muscles and adductors were significantly more affected than in patients with dermatomyositis and polymyositis. Inclusion body myositis (IBM) was characterized by marked anterior thigh involvement, which stabilized or progressed at follow-up imaging. Atrophy and FR grades improved over time in some non-IBM IIM patients. DISCUSSION: Patients with IMNM and IBM have characteristic patterns of muscle MRI abnormalities that may allow them to be differentiated radiologically from other IIM subtypes. Muscle damage in non-IBM IIM may be reversible.

Intraperitoneal Local Anesthetic Instillation and Postoperative Infusion Improves Functional Recovery Following Colectomy: A Randomized Controlled Trial.

BACKGROUND: Intraperitoneal local anesthetic is an analgesic technique for inclusion in the polypharmacy approach to postoperative pain management in enhanced recovery after surgery programs. Previously, augmentation of epidural analgesia with intraperitoneal local anesthetic was shown to improve functional postoperative recovery following colectomy. OBJECTIVE: This study determines whether intraperitoneal local anesthetic improves postoperative recovery in patients undergoing colectomy, in the absence of epidural analgesia, with standardized enhanced recovery after surgery perioperative care. DESIGN: This is a multisite, double-blinded, randomized, placebo-controlled trial (ClinicalTrials.gov Identifier NCT02449720). SETTINGS: This study was conducted at 3 hospital sites in South Australia. PATIENTS: Eighty-six adults undergoing colectomy were stratified by approach (35 open; 51 laparoscopic), then randomly assigned to intraperitoneal local anesthetic (n = 44) and control (n = 42) groups. INTERVENTIONS: Patients in the intraperitoneal local anesthetic group received an intraoperative intraperitoneal ropivacaine 100-mg bolus both pre- and postdissection and 20 mg/h continuous postoperative infusion for 48 hours. Patients in the control group received a normal saline equivalent. MAIN OUTCOME MEASURES: Functional postoperative recovery was assessed by using the surgical recovery scale for 45 days; postoperative pain was assessed by using a visual analog scale; and opioid consumption, use of rescue ketamine, recovery of bowel function, time to readiness for discharge, and perioperative complications were recorded. RESULTS: The intraperitoneal local anesthetic group reported improved surgical recovery scale scores at day 1 and 7, lower pain scores, required less rescue ketamine, and passed flatus earlier than the control group (p < 0.05). The improvement in surgical recovery scale at day 7 and pain scores remained when laparoscopic colectomy was considered separately. Opioid consumption and time to readiness for discharge were equivalent. LIMITATIONS: This study was powered to detect a difference in surgical recovery scale, but not the other domains of recovery, when the intraperitoneal local anesthetic group was compared with control. CONCLUSIONS: We conclude that instillation and infusion of intraperitoneal ropivacaine for patients undergoing colectomy, including by the laparoscopic approach, decreases postoperative pain and improves functional postoperative recovery. We recommend routine inclusion of intraperitoneal local anesthetic into the multimodal analgesia component of enhanced recovery after surgery programs for laparoscopic colectomy. See Video Abstract at http://links.lww.com/DCR/A698.

An evaluation of risk factors to predict target concentration non-attainment in critically ill patients prior to empiric ß-lactam therapy.

To determine whether target concentration non-attainment can be anticipated in critically ill patients prior to initiating empiric ß-lactam antibiotic therapy based on readily available clinical factors. Retrospective review of consecutive patients treated with piperacillin or meropenem and who underwent therapeutic drug monitoring (TDM) at St Vincent's Hospital (Sydney, Australia) between January 2013 and December 2015 was performed. Predefined subgroups were patients who received continuous renal replacement therapy (CRRT) and those who did not (non-CRRT). Potential risk factors were evaluated by correlation with ß-lactam antibiotic trough concentrations (Cmin) lower than or equal to targeted minimum inhibitory concentration (MIC). Only the first drug concentration after initiation of the antibiotic treatment was included to reflect empirical dose selection. A total of n = 249 patients (piperacillin, n = 169; meropenem, n = 80) were investigated. For non-CRRT patients (n = 210), multivariate analysis demonstrated the following: male gender (p = 0.006); younger age (p = 0.015); prescribed daily antibiotic dose less than 1.5 times the product information recommendations (p = 0.004); lack of positive microbiology (p = 0.006); lower overall illness severity (p = 0.005); and estimated glomerular filtration rate (eGFR) ≥ 90 mL/min/1.73 m2 (p < 0.001), to be associated with Cmin ≤ MIC. No predictor variable was found to be significantly associated with Cmin ≤ MIC for the CRRT cohort. Evaluating the risk of target concentration non-attainment using simple clinical factors is possible at the bedside for non-CRRT patients prior to empiric antibiotic initiation. Clinicians should be wary of selecting doses based on the product information especially when treating younger male patients with apparently 'normal' renal function.

Too much of a good thing: a retrospective study of ß-lactam concentration-toxicity relationships.

Objectives: To determine the existence of concentration-toxicity relationships for common ß-lactam antibiotic adverse effects and define thresholds above which toxicity is more likely. Patients and methods: Retrospective review of consecutive patients treated with piperacillin, meropenem or flucloxacillin who underwent therapeutic drug monitoring (TDM) at St Vincent's Hospital (Sydney, Australia) between January 2013 and December 2015. Adverse events investigated included neurotoxicity, nephrotoxicity, hepatotoxicity and opportunistic Clostridium difficile infection. Toxicity was measured using observational grading criteria, clinical assessment and relevant serum biomarkers. These findings were correlated with trough TDM measurements at the time of toxicity presentation. Results: TDM results from 378 patients (piperacillin = 223, meropenem = 94 and flucloxacillin = 61) were investigated. There was no difference in baseline patient characteristics across antibiotic groups. A statistically significant elevation in mean serum trough concentrations (Cmin) was found in patients diagnosed with neurotoxicity (piperacillin, P < 0.01; meropenem, P = 0.04; flucloxacillin, P = 0.01) and those who developed nephrotoxicity whilst being treated with piperacillin (P < 0.01) or meropenem (P < 0.01). Incidence of hepatotoxicity and C. difficile was not related to Cmin. Threshold concentrations for which there is 50% risk of developing a neurotoxicity event (piperacillin, Cmin >361.4 mg/L; meropenem, Cmin >64.2 mg/L; flucloxacillin, Cmin >125.1 mg/L) or nephrotoxicity (piperacillin, Cmin >452.65 mg/L; meropenem, Cmin >44.45 mg/L) varied across antibiotics. Conclusions: Our data reveal an association between toxic concentrations for a number of ß-lactam agents and neurotoxic/nephrotoxic effects. We have defined threshold concentrations above which these toxicities become more likely. Clinicians should balance concerns for therapeutic efficacy with potential toxicity when considering aggressive therapy.

Impact of perinatal exposure to sucrose or high fructose corn syrup (HFCS-55) on adiposity and hepatic lipid composition in rat offspring.

KEY POINTS: Fructose-containing sugars, including sucrose and high fructose corn syrup (HFCS), have been implicated in the epidemics of obesity and type 2 diabetes. Few studies have evaluated the impact of perinatal exposure to these sugars on metabolic and physiological outcomes in the offspring. Using a rat model, offspring exposed to a maternal sucrose or HFCS diet during the prenatal and/or suckling periods were found to have altered adiposity and liver fat content and composition at weaning. Plasma levels of free fatty acids remained elevated in young adulthood, but consumption of a control diet following weaning appeared to ameliorate most other effects of perinatal exposure to a maternal high-sugar diet. Guidelines for maternal nutrition should advise limiting consumption of fructose-containing sugars, and it is particularly important that these recommendations include maternal nutrition during lactation. ABSTRACT: Perinatal exposure to excess maternal intake of added sugars, including fructose and sucrose, is associated with an increased risk of obesity and type 2 diabetes in adult life. However, it is unknown to what extent the type of sugar and the timing of exposure affect these outcomes. The aim of this study was to determine the impact of exposure to maternal consumption of a 10% (w/v) beverage containing sucrose or high fructose corn syrup-55 (HFCS-55) during the prenatal and/or suckling periods on offspring at 3 and 12 weeks, utilising a cross-fostering approach in a rodent model. Perinatal sucrose exposure decreased plasma glucose concentrations in offspring at 3 weeks, but did not alter glucose tolerance. Increased adiposity was observed in 3-week-old offspring exposed to sucrose or HFCS-55 during suckling, with increased hepatic fat content in HFCS-55-exposed offspring. In terms of specific fatty acids, hepatic monounsaturated (omega-7 and -9) fatty acid content was elevated at weaning, and was most pronounced in sucrose offspring exposed during both the prenatal and suckling periods, and HFCS-55 offspring exposed during suckling only. By 12 weeks, the effects on adiposity and hepatic lipid composition were largely normalised. However, exposure to either sucrose or HFCS-55 during the prenatal period only was associated with elevated plasma free fatty acids at weaning, and this effect persisted until 12 weeks. This study suggests that the type of sugar and the timing of exposure (prenatal or suckling periods) are both important for determining the impact on metabolic health outcomes in the offspring.

Fructose Beverage Consumption Induces a Metabolic Syndrome Phenotype in the Rat: A Systematic Review and Meta-Analysis.

A high intake of refined carbohydrates, particularly the monosaccharide fructose, has been attributed to the growing epidemics of obesity and type-2 diabetes. Animal studies have helped elucidate the metabolic effects of dietary fructose, however, variations in study design make it difficult to draw conclusions. The aim of this study was to review the effects of fructose beverage consumption on body weight, systolic blood pressure and blood glucose, insulin and triglyceride concentrations in validated rat models. We searched Ovid Embase Classic + EmbaseMedline and Ovid Medline databases and included studies that used adolescent/adult male rats, with fructose beverage consumption for >3 weeks. Data from 26 studies were pooled by an inverse variance weighting method using random effects models, expressed as standardized mean differences (SMD) with 95% confidence intervals (CI). Overall, 10%-21% w/v fructose beverage consumption was associated with increased rodent body weight (SMD, 0.62 (95% CI: 0.18, 1.06)), systolic blood pressure (SMD, 2.94 (95% CI: 2.10, 3.77)) and blood glucose (SMD, 0.77 (95% CI: 0.36, 1.19)), insulin (SMD, 2.32 (95% CI: 1.57, 3.07)) and triglyceride (SMD, 1.87 (95% CI: 1.39, 2.34)) concentrations. Therefore, the consumption of a low concentration fructose beverage is sufficient to cause early signs of the metabolic syndrome in adult rats.

Fructose, pregnancy and later life impacts.

Fructose is an increasingly common constituent of the Westernized diet due to cost and production efficiencies. Although an integral component of our pre-industrial revolution diet, over the past two decades human and animal studies have highlighted that excessive fructose intake appears to be associated with adverse metabolic effects. Excessive intake of fructose is the combined result of increased total energy consumption and increased portion sizes of foods, which often incorporate the fructose-containing sugars sucrose and high-fructose corn-syrup (HFCS). The adverse metabolic effects following excessive fructose consumption have become a hot topic in mainstream media and there is now rigorous scientific debate regarding periods of exposure, dosage levels, interactive effects with other sugars and fats and mechanisms underlying the actions of fructose. There is still a degree of controversy regarding the extent to which sugars such as sucrose and HFCS have contributed to the current epidemic of obesity and diabetes. Furthermore, an increasing number of infants are being exposed to sugar-sweetened food and beverages before birth and during early postnatal life, highlighting the importance of determining the long-term effects of this perinatal exposure on the developing offspring. There are limited human observational and controlled studies identifying associations of excessive sweetened food and beverage consumption with poor pregnancy outcomes. Animal research has demonstrated an increased incidence of gestational diabetes as well as altered maternal, fetal and offspring metabolic function, although the long-term effects and the mechanism underlying these perturbations are ill defined. This review aims to understand the role of early life fructose exposure in modifying postnatal risk of disease in the offspring, focusing on fructose intake during pregnancy and in early postnatal life.

Changes in cardiac troponins with gestational age explain changes in cardiac muscle contractility in the sheep fetus.

The development of the adult cardiac troponin complex in conjunction with changes in cardiac function and cardiomyocyte binucleation has not been systematically characterized during fetal life in a species where maturation of the cardiomyocytes occurs prenatally as it does in the human. The aim of this study was to correlate the expression of each of the major adult troponin isoforms (T, I, and C) during late gestation (term of 150 days) to changes in both Ca(2+) sensitivity and maximum Ca(2+)-activated force of the contractile apparatus and the maturation of cardiomyocytes. The percentage of mononucleated cardiomyocytes in the right ventricle decreased with gestational age to 46% by 137-142 days of gestation. The length of binucleated cardiomyocytes did not change with gestational age, but the length of binucleated cardiomyocytes relative to heart weight decreased with gestational age. There was no change in the expression of adult cardiac troponin T with increasing gestation. The contractile apparatus was significantly more sensitive to Ca(2+) at 90 days compared with either 132 or 139 days of gestation, consistent with an ∼30% increase in the expression of adult cardiac troponin I between 90 and 110 days of gestation. Maximum Ca(2+)-activated force significantly increased from 90 days compared with 130 days consistent with an increase of ∼40% in cardiac troponin C protein expression. These data show that increased adult cardiac troponin I and C protein expression across late gestation is consistent with reduced Ca(2+) sensitivity and increased maximum Ca(2+)-activated force. Furthermore, changes in cardiac troponin C, not I, protein expression track with the timing of cardiomyocyte binucleation.

Heifer nutrient intake during early- and mid-gestation programs adult offspring adiposity and mRNA expression of growth-related genes in adipose depots.

Changes in maternal nutrient intake during gestation alter IGF receptor abundance and leptin (LEP) mRNA expression in fetal adipose tissue. It is not known whether such changes persist into adult life and whether they are associated with an effect on phenotype. We investigated the effect of high (240%) and low (70%) levels of recommended daily crude protein intake for beef heifers during the first and second trimesters of gestation on singleton progeny (n=68): subcutaneous (SC) adipose tissue depth at rump (P8) and rib (RF) sites from 65 until 657 days of age; plasma leptin concentrations from birth until 657 days and expression of IGF1 and IGF2, their receptors (IGF1R and IGF2R) and LEP mRNA in perirenal (PR), omental (OM) and SC adipose tissue at 680 days of age. High-protein diets during the first trimester increased LEP and IGF1 mRNA in PR of males and females, respectively, compared with low-protein diets, and decreased IGF1R mRNA in SC of all progeny but increased RF depth of males between 552 and 657 days. High-protein diets compared with low-protein diets during the second trimester increased IGF1R mRNA in PR and OM of all progeny; LEP mRNA in PR of males; and IGF2 and IGF2R mRNA in OM of all progeny. Conversely, LEP mRNA in OM and IGF2 mRNA in PR of all progeny were decreased following exposure to high- compared with low-protein diets during the second trimester. Heifer diet during gestation has permanent sex- and depot-specific effects on the expression of adipogenic and adipocytokine genes and offspring adiposity.

Fetal growth restriction, catch-up growth and the early origins of insulin resistance and visceral obesity.

There is an association between growing slowly before birth, accelerated growth in early postnatal life and the emergence of insulin resistance, visceral obesity and glucose intolerance in adult life. In this review we consider the pathway through which intrauterine growth restriction (IUGR) leads to the initial increase in insulin sensitivity and to catch-up growth. We also discuss the importance of the early insulin environment in determining later visceral adiposity and the intrahepatic mechanisms that may result in the emergence of glucose intolerance in a subset of IUGR infants. We present evidence that a key fetal adaptation to poor fetal nutrition is an upregulation of the abundance of the insulin receptor in the absence of an upregulation of insulin signalling in fetal skeletal muscle. After birth, however, there is an upregulation in the abundance of the insulin receptor and the insulin signalling pathway in the IUGR offspring. Thus, the origins of the accelerated postnatal growth rate experienced by IUGR infants lie in the fetal adaptations to a poor nutrient supply. We also discuss how the intracellular availability of free fatty acids and glucose within the visceral adipocyte and hepatocyte in fetal and neonatal life are critical in determining the subsequent metabolic phenotype of the IUGR offspring. It is clear that a better understanding of the relative contributions of the fetal and neonatal nutrient environment to the regulation of key insulin signalling pathways in muscle, visceral adipose tissue and the liver is required to support the development of evidence-based intervention strategies and better outcomes for the IUGR infant.

The early origins of later obesity: pathways and mechanisms.

Excess bodyweight is the sixth most important risk factor contributing to the overall burden of disease worldwide. In excess of a billion adults and 10% of all children are now classified as overweight or obese. The main adverse consequences of obesity are the metabolic syndrome, cardiovascular disease and type 2 diabetes and a diminished average life expectancy. It has been argued that the complex pathological processes underlying obesity reflect environmental and genetic interactions, and individuals from disadvantaged communities seem to have greater risks than more affluent individuals partly because of fetal and postnatal programming interactions. Abundant evidence indicates that the obesity epidemic reflects progressive secular and age-related decreases in physical activity, together with passive over-consumption of energy dense foods despite neurobiological processes designed to regulate energy balance. The difficulty in treating obesity, however, highlights the deficits in our current understanding of the pathophysiology which underlies the initiation and chronic nature of this disorder. Large population based studies in Europe and North America in healthy women and in women with gestational diabetes have demonstrated that there are clear relationships between maternal and fetal nutrient supply, fetal growth patterns and the subsequent risk of obesity and glucose intolerance in childhood and adult life. In this review we discuss the impact of fetal nutrition on the biology of the developing adipocyte and brain and the growing evidence base supporting an intergenerational cycle of obesity.

Intrauterine growth restriction and differential patterns of hepatic growth and expression of IGF1, PCK2, and HSDL1 mRNA in the sheep fetus in late gestation.

Fetal adaptations to periods of substrate deprivation can result in the programming of glucose intolerance, insulin resistance, and metabolic dysfunction in later life. Placental insufficiency can be associated with either sparing or sacrifice of fetal liver growth, and these different responses may have different metabolic consequences. It is unclear what intrahepatic mechanisms determine the differential responses of the fetal liver to substrate restriction. We investigated the effects of placental restriction (PR) on liver growth and the hepatic expression of SLC2A1, IGF1, IGF2, IGF1R, IGF2R, PPARGC1A, PPARA, PRKAA1, PRKAA2, PCK2, and HSDL1 mRNA in fetal sheep at 140-145 days of gestation. A mean gestational arterial partial pressure of oxygen less than 17 mmHg was defined as hypoxic, and a relative liver of weight more than 2 SD below the mean liver weight of controls was defined as reduced liver growth. Fetuses therefore were defined as control-normoxic (C-N; n = 9), PR-normoxic (PR-N; n = 7), PR-hypoxic (PR-H; n = 8), or PR-hypoxic reduced liver growth (PR-H RLG; n = 4). Hepatic SLC2A1 mRNA expression was highest (P < 0.05) in the PR-H fetuses, in which liver growth was maintained. Expression of IGF1 mRNA was decreased (P < 0.05) only in the PR-H RLG group. Hepatic expression of HSDL1, PPARGC1A, and PCK2 mRNA also were increased (P < 0.05) in the PR-H RLG fetuses. The present study highlights that intrahepatic responses to fetal substrate restriction may exist that protect the liver from decreased growth and, potentially, from a decreased responsiveness to the actions of insulin in postnatal life.

Developmental origins of adult health and disease: the role of periconceptional and foetal nutrition.

The 'developmental origins of adult health and disease' hypothesis stated that environmental factors, particularly maternal undernutrition, act in early life to programme the risks for adverse health outcomes, such as cardiovascular disease, obesity and the metabolic syndrome in adult life. Early physiological tradeoffs, including activation of the foetal hypothalamo-pituitary-adrenal (HPA) axis, confer an early fitness advantage such as foetal survival, while incurring delayed health costs. We review the evidence that such tradeoffs are anticipated from conception and that the periconceptional nutritional environment can programme the developmental trajectory of the stress axis and the systems that maintain and regulate arterial blood pressure. There is also evidence that restriction of placental growth and function, results in an increased dependence of the maintenance of arterial blood pressure on the sequential recruitment of the sympathetic nervous system and HPA axis. While the 'early origins of adult disease' hypothesis has focussed on the impact of maternal undernutrition, an increase in maternal nutritional intake and in maternal body mass intake has become more prevalent in developed countries. Exposure to overnutrition in foetal life results in a series of central and peripheral neuroendocrine responses that in turn programme development of the fat cell and of the central appetite regulatory system. While the physiological responses to foetal undernutrition result in the physiological trade off between foetal survival and poor health outcomes that emerge after reproductive senescence, exposure to early overnutrition results in poor health outcomes that emerge in childhood and adolescence. Thus, the effects of early overnutrition can directly impact on reproductive fitness and on the health of the next generation. In this context, the physiological responses to relative overnutrition in early life may directly contribute to an intergenerational cycle of obesity.

Impact of periconceptional undernutrition on adrenal growth and adrenal insulin-like growth factor and steroidogenic enzyme expression in the sheep fetus during early pregnancy.

Periconceptional undernutrition (PCUN) results in an earlier prepartum activation of the pituitary-adrenal axis in twin compared with singleton fetuses. We have tested the hypotheses that the functional development of the fetal sheep adrenal is delayed in twins compared with singletons in early gestation and that PCUN accelerates adrenal growth and increases the expression of intraadrenal IGF-I and -II and cytochrome P450 17-hydroxylase (CYP17) as early as 55 d gestation. We have investigated the effect of PCUN in the ewe (restricted at 70% of control allowance, n=21; control, n=24) from at least 45 d before mating until d 7 after mating on maternal cortisol and progesterone concentrations, fetal adrenal weight, adrenal IGF-I, IGF-I receptor (IGF-IR), IGF-II, IGF-IIR, and CYP17 mRNA expression and placental 11beta-hydroxysteroid dehydrogenase-1 and -2 mRNA and protein expression at d 53-56 pregnancy. The relative weight of the fetal adrenal and adrenal IGF-I, IGF-IR, IGF-II, IGF-IIR, and CYP17 mRNA expression were lower in twin compared with singleton fetuses. In singleton fetuses of PCUN ewes, there was a loss of the relationship between adrenal IGF-II/IGF-IIR expression and either adrenal weight or CYP17 mRNA, which was present in controls. Similarly in twin fetuses, PCUN resulted in the loss of the relationships between adrenal weight and IGF-I expression and between adrenal CYP17 and IGF-II expression, which were present in controls. Our findings suggest that differences in the timing of the prepartum activation of the fetal adrenal in twins and singletons have their origins in early gestation and highlight the importance of the interaction between the periconceptional environment and embryo number in setting the growth trajectory of the fetal adrenal.

Differential regulation of suppressor of cytokine signaling-3 in the liver and adipose tissue of the sheep fetus in late gestation.

It is unknown whether the JAK/STAT/suppressor of cytokine signaling-3 (SOCS-3) intracellular signaling pathway plays a role in tissue growth and metabolism during fetal life. We investigated whether there is a differential profile of SOCS-3 expression in the liver and perirenal adipose tissue during the period of increased fetal growth in late gestation and the impact of fetal growth restriction on SOCS-3 expression in the fetal liver. We also determined whether basal SOCS-3 expression in the fetal liver and perirenal adipose tissue is regulated by endogenous fetal prolactin (PRL). SOCS-3 mRNA abundance was higher in the liver than in the pancreas, spleen, and kidney of the sheep fetus during late gestation. In the liver, SOCS-3 mRNA expression was increased (P < 0.05) between 125 (n = 4) and 145 days (n = 7) gestation and lower (P < 0.05) in growth-restricted compared with normally grown fetal sheep in late gestation. The relative expression of SOCS-3 mRNA in the fetal liver was directly related to the mean plasma PRL concentrations during a 48-h infusion of either a dopaminergic agonist, bromocriptine (n = 7), or saline (n = 5), such that SOCS-3 mRNA expression was lower when plasma PRL concentrations decreased below approximately 20 ng/ml [y = 0.99 - (2.47/x) + (4.96/x(2)); r(2) = 0.91, P < 0.0001, n = 12]. No relationship was shown between the abundance of phospho-STAT5 in the fetal liver and circulating PRL. SOCS-3 expression in perirenal adipose tissue decreased (P < 0001) between 90-91 (n = 6) and 140-145 days (n = 9) gestation and was not related to endogenous PRL concentrations. Thus SOCS-3 is differentially expressed and regulated in key fetal tissues and may play an important and tissue-specific role in the regulation of cellular proliferation and differentiation before birth.