Efeito da administração da hormona PGF2α nos problemas pós-parto, mais concretamente na retenção placentária em bovinos leiteiros

Dissertação de Mestrado em Engenharia Zootécnica/Produção Animal

Role of chemerin and its receptors in mouse models of tumorigenesis

Dissertação de Mestrado, Oncobiologia: Mecanismos Moleculares do Cancro, Departamento de Ciências Biomédicas e Medicina, Universidade do Algarve, 2015

A cross sectional study of leptospirosis and fetal death in Yucatan, Mexico

Introduction: Leptospirosis is a zoonotic disease affecting mainly to low income human population. Acute leptospiral infection during pregnancy has been associated with spontaneous abortion and fetal death during the first trimester and the abortion may occur as consequence of systemic failure. Objective: To estimate the frequency of Leptospira interrogans infection in women with spontaneous abortion in the state of Yucatan, Mexico. Methods: A cross sectional study on women with spontaneous abortion was conducted. Serum samples were tested for Leptospirosis by the microaglutination test, to estimate the frequency of the infecting serovar. The indirect ELISA IgM was used to detect recent infection by L. interrogans. DNA was extracted from paraffin-embedded tissue of placenta for PCR detection of L. interrogans. Results: Overall frequency of infection with L. interrogans in the 81 women with abortion was 13.6%. Five of the 12 serovars evaluated were found and included. Two of the 11 women with abortion and positive to microaglutination test were also positive to the ELISA IgM test. None samples were positive for PCR Leptospira diagnosis. Conclusion: two women could be associated with spontaneous abortion due to leptospirosis, because they showed antibodies against L. interrogans in the microaglutination test and ELISA IgM assays. Differences between regions were found with respect to the prevalences of lesptospirosis.

Perinatal complications associated with preterm deliveries at 24 to 33 weeks and 6 days gestation (2011- 2012): A hospital-based retrospective study

Background: Morbidity and mortality of preterm babies are important issues in perinatal medicine. In developed countries, preterm delivery is the cause of about 70% of mortality and 75% of morbidity in the neonatal period, respectively. Objective: The aim of this study was to determine the risk factors for preterm labor and the outcomes, in terms of perinatal mortality and morbidity at the time of discharge home, among preterm infants at less than 34 weeks gestation. Materials and Methods: A retrospective study was conducted and all infants with a gestational age of 24 to 33 weeks and 6 days who were born from November 1st , 2011 to March 31, 2012 were enrolled in this study. Results: From 1185 preterm infants were born during this period, 475 (40.08%) infants with less than 34 weeks gestational age were included in the study. Our study showed the major obstetrical risk factors for preterm labor were as follows: preeclampsia (21%), premature rupture of membranes (20.3%), abruption of placenta (10%), and idiopathic cases (48.7%). The neonatal mortality rate in less than 34 weeks was 9.05%. Significant perinatal morbidity causesd in less than 34 weeks were as follows: sepsis (46.94%), respiratory distress syndrome (41.47%), patent ductus arteriosus (21.47%), retinopathy of prematurity (3.57%), necrotizing entrocolitis (1.68%), intra-ventricular hemorrhage (9%), and broncho-pulmonary dysplasia (0.84%). Conclusion: Preterm birth is associated with adverse perinatal outcome. This situation needs to be improved by directing appropriately increased resources for improving prenatal health services and providing advanced neonatal care.

Conjoined twins in a monochorionic triplet pregnancy after in vitro fertilization: a case report

Background: Monozygotic monochorionic triplet pregnancy with conjoined twins is a very rare condition and is associated with many complications. Case: In this study, we describe a monochorionic–diamniotic triplet pregnancy after in vitro fertilization with an intracytoplasmic sperm injection. At a gestational age of 6 weeks and 4 days of pregnancy one gestational sac was observed, and at a gestational age of 12 weeks and 2 days, triplets with conjoined twins were diagnosed. After consulting with the parents, they chose fetal reduction of the conjoined twins. Selective feticide was successfully performed by radiofrequency ablation at 16 weeks of pregnancy. Unfortunately, the day after the procedure, the membrane ruptured, and 1 week later, all fetuses and placenta were spontaneously aborted. Conclusion: Monochorionic triplet pregnancy with conjoined twins is very rare. These pregnancies are associated with very serious complications. Intra cytoplasmic sperm injection increases the rate of monozygotic twinning and conjoined twins. Counseling with parents before IVF is very important.

The rat placental renin-angiotensin system - a gestational gene expression study

BACKGROUND: The placenta is an essential organ that provides nutrients and oxygen to the developing fetus and removes toxic waste products from the fetal circulation. Maintaining placental blood osmotic pressure and blood flow is crucial for viable offspring. The renin-angiotensin system (RAS) in the placenta is a key player in the regulation of maternal-fetal blood flow during pregnancy. Therefore, the aim of this study was to determine if RAS genes are differentially expressed in mid to late gestation in rat placenta. METHODS: Whole placental tissue samples from pregnant Sprague Dawley rats at embryonic (E) days 14.25, 15.25, 17.25 and 20 (n = 6 for each gestational age) were used for genome-wide gene expression by microarray. RAS genes with expression differences of >2 fold were further analyzed. Quantitative Real-Time PCR (qPCR) was performed on independent samples to confirm and validate microarray data. Immunohistochemisty and Western blotting were performed on a differentially expressed novel RAS pathway gene (ANPEP). RESULTS: Six out of 17 genes of the RAS pathway were differentially expressed at different gestational ages. Gene expression of four genes (Angiotensin converting enzyme (Ace), angiotensin converting enzyme 2 (Ace2), membrane metalloendopeptidase (Mme) and angiotensin II receptor 1A (Agtr1a)) were significantly upregulated at E20 whereas two others (Thimet oligopeptidase 1 (Thop1) and Alanyl aminopeptidase (Anpep)) were downregulated at E20 prior to the onset of labour. These changes were confirmed by qPCR. Western blots revealed no overall differences in ANPEP protein expression in the placentae. Immunohistochemical studies, however, indicated that the localization of ANPEP differed at E17.25 and E20 as ANPEP localization in the giant trophoblast cell of the junctional zone was no longer detectable at E20. CONCLUSIONS: The current study investigated the expression of members of the RAS pathway in rat placentae and observed significantly altered expression of 6 RAS genes at 4 gestational ages. These findings present the need for further comprehensive investigation of RAS genes in normal and complicated pregnancies.

Proposal to minimize the difficulty of recording abortion data in sheep

Background: The most frequent viral diseases which can cause abortion in sheep are Blue tongue, Border disease virus, Cache Valley fever and Schmallenberg virus. The diagnosis of abortion, namely virus-induced represents a challenge to field clinicians, since clinical signs presented by the dam are discrete, non-specific and variable (Agerhom et al., 2015). On the other hand, while some foetuses reveal characteristic and visible malformations, others do not reveal any lesions. In face of it, definitive diagnosis requires an appropriate history collection, as well as sending fresh samples, namely abortion material, foetus, placenta and umbilical cord, to a specialty laboratory, to obtain a precise diagnosis. Objectives: The authors suggest a registration method of all mandatory data, in order to further assist the diagnosis of viral diseases at the laboratories, including the most frequent congenital malformations reported in sheep abortions. Methods: Abortion samples of suspected viral origin were collected and all data were registered, in worktables optimized for this purpose. Results: The authors document, using macroscopic figures lesions of malformations in abortions, emphasizing the frequency and the importance of documenting each case, proposing practical and effective worktables to assist the fieldwork. Conclusions: Field clinician’s awareness of the importance of early detection of viral diseases causing abortion outbreaks stimulates a proper data collection for each case of abortion, in order to contribute to a precise diagnosis and posterior consistent epidemiological studies, which may allow diminishing of economic losses.

Salmonella Enterica serovar Typhimurium Infection in Mouse Pregnancy

Salmonella are Gram-negative, intracellular food-borne pathogens that cause pregnancy complications. In pregnant mice, Salmonella enterica serovar Typhimurium (S.Tm) infection results in placental bacterial replication, inflammation, necrosis, and fetal loss by unknown mechanisms. Necroptosis, or programmed necrosis mediated by RIPK3 (receptor-interacting protein kinase 3), an inflammatory cell death pathway, is implicated in the pathogenesis of S.Tm in non-pregnant mice. This goal of this thesis was to investigate the role of necroptosis in the pathogenesis of S.Tm infection during mouse pregnancy. I hypothesized that elimination of the key necroptotic cell death protein RIPK3 would decrease placental inflammation and trophoblast cell death, and increase conceptus survival compared to controls. Mice expressing a functional Slc11a1 (encodes the natural resistance-associated macrophage protein 1, NRAMP1) gene with or without RIPK3 function (Ripk3-/-Slc11a1+/+ compared to Slc11a1+/+) were infected with 103 S.Tm by tail vein injection on gestational day (GD) 12. Mice were euthanized on GD 14 (48h post-infection) or GD 15 (72h post-infection) and implantation sites (IS) and maternal serum were harvested for analyses. In nearly all challenged mice (except one outlier), S.Tm were detected in most IS within a litter but there was limited immune cell infiltration, placental damage or cell death in Slc11a1 competent mice regardless of Ripk3 gene deletion. Maternal serum cytokine analyses confirmed lack of maternal immune responses to S.Tm infection. IS amongst the litter of a single dam (Ripk3-/-Slc11a1+/+ at 72h postinfection) displayed heavy but not universal placental S.Tm infection of decidual tissues and spongiotrophoblast, associated with elevated maternal serum pro-inflammatory cytokines. S.Tm infection of the fetal yolk sac (YS) was observed in 54.5% of IS from this dam. YS infection was confirmed in archival samples in mice expressing Ripk3 with intact Slc11a1 and in mice lacking functional Slc11a1. In Slc11a1 incompetent mice, S.Tm were detected in placental labyrinthine trophoblast. Based on the available data, this thesis suggests that Ripk3 and necroptosis have no significant roles in either promotion or prevention of progressive Salmonella infection during mouse pregnancy. It also provides pilot data that NRAMP1 controls placental localization and lethality due to YS infection.

Milk: milk of monotremes and marsupials

Lactation has evolved from an ancient reproductive strategy which appears to have been present long before the evolution of extantmammals. The ability to lactate is a feature only found among mammals and involves a facet of maternal care where mothers secretea nutrient-rich milk which is delivered to the young by the mammary gland. Evolutionary studies indicate that lactation was establishedprior to divergence of extant mammalian lineages. It also seems that lactation evolved long before gestation in utero. Secretionsof ancestral mammary glands may have had antimicrobial properties that protected either eggs or hatchlings and organiccomponents that supplemented offspring nutrition. Over the course of evolution, lactation became a highly efficient, effectiveand adaptable means of providing maternal care for neonates. The evolution of a placenta in eutherian mammals resulted inmore extensive intrauterine development of an embryo and the ability to lactate after birth became a critical part of the reproductivestrategy of mammalian species. Following development of highly nutritious milks, evolution produced diversity in milk compositionand function, quantity of milk output, length of lactation, length of intervals between nursing and contributions of lactation tooffspring nutrition.

Maternal creatine in pregnancy: a retrospective cohort study.

OBJECTIVE: To estimate creatine concentrations in maternal plasma and urine, and establish relationships with maternal characteristics, diet and fetal growth. DESIGN: Retrospective cohort study. SETTING: Lyell McEwin Hospital, Adelaide, Australia. POPULATION: A biobank of plasma and urine samples collected at 13, 18, 30 and 36 weeks' gestation from 287 pregnant women from a prospective cohort of asthmatic and non-asthmatic women. METHODS: Creatine was measured by enzymatic analysis. Change in creatine over pregnancy was assessed using the Friedman test. Linear mixed models regression was used to determine associations between maternal factors and diet with creatine across pregnancy and between creatine with indices of fetal growth at birth. MAIN OUTCOME MEASURES: Maternal creatine concentrations, associations between maternal factors and creatine and between creatine and fetal growth parameters. RESULTS: Maternal smoking, body mass index, asthma and socio-economic status were positively and parity negatively associated with maternal plasma and/or urine creatine. Maternal urine creatine concentration was positively associated with birthweight centile and birth length. After adjustment, each μmol/l increase in maternal urinary creatine was associated with a 1.23 (95% CI 0.44-2.02) unit increase in birthweight centile and a 0.11-cm (95% CI 0.03-0.2) increase in birth length. CONCLUSIONS: Maternal factors and fetal growth measures are associated with maternal plasma and urine creatine concentrations. TWEETABLE ABSTRACT: Maternal creatine is altered by pregnancy; fetal growth measures are associated with maternal creatine concentrations.

"My midwife said that having a glass of red wine was actually better for the baby": a focus group study of women and their partner's knowledge and experiences relating to alcohol consumption in pregnancy.

BACKGROUND: While it is well established that alcohol can cross the placenta to the foetus and can affect an infant's development, many women continue to drink during pregnancy. For this reason it is important to determine what information is being provided, what information may be missing, and the preferred sources of information on this issue. In order to improve prevention strategies, we sought to understand the knowledge and experiences of pregnant women and their partners regarding the effects of alcohol consumption during pregnancy. METHODS: The current study utilised a qualitative study design in order to gain insight into the views and experiences of pregnant women, newly delivered mothers and their partners. Focus groups examined the participant's knowledge about the effects of alcohol consumption during pregnancy, the sources of information on this issue, and the psycho-social influences on their drinking behaviour. Five focus groups were conducted involving a total of 21 participants (17 female). A six-stage thematic analysis framework was used to analyse all focus group discussions in a systematic way. RESULTS: Seven major themes were identified from the focus group data: 1) knowledge of Foetal Alcohol Spectrum Disorders; 2) message content and sources; 3) healthcare system; 4) society and culture; 5) partner role; 6) evaluation of risk; and 7) motivation. The findings indicated that although the majority of participants knew not to drink alcohol in pregnancy they had limited information on the specific harmful effects. In addition, routine enquiry and the provision of information by health care professionals were seen as lacking. CONCLUSIONS: The findings of this research provide important insights in to the relationship between pregnant women, their partners, and their healthcare providers. Several recommendations can be made on the basis of these findings. Firstly, public health messages and educational materials need to provide clear and consistent information about the effects of alcohol consumption on the developing baby. Additionally, more thorough and consistent routine enquiry for alcohol consumption in pregnant women needs to occur. Finally, it is important to ensure ongoing education for health professionals on the issue of alcohol consumption during pregnancy.

A critical review of public health interventions aimed at reducing alcohol consumption and/or increasing knowledge among pregnant women.

ISSUES: It is well established that alcohol can cross the placenta to the fetus and can affect both physical and psychological development of the infant; however, many women continue to drink during pregnancy. It is therefore important to determine whether interventions can be successful in reducing alcohol consumption among pregnant women. Past reviews have investigated the effectiveness of clinical interventions in reducing alcohol consumption in pregnancy; however, the aim of the current review was to focus on the effectiveness of public health interventions. APPROACH: A critical literature review was conducted by searching several electronic databases using key words such as 'pregnancy', 'alcohol', 'interventions' and 'public health'. Studies were included if they utilised a public health intervention and included alcohol consumption or levels of knowledge as an outcome measure. KEY FINDINGS: Seven studies were included in the review. Interventions included multimedia and educational interventions. Improvements in knowledge were reported in six studies, whereas one study found contradictory results. Four studies used alcohol consumption rates as an outcome measure, and although a reduction in consumption was reported, the results were non-significant. IMPLICATIONS: The effectiveness of public health interventions that aim to increase awareness and reduce alcohol consumption among pregnant women cannot be assessed because of the paucity of studies. CONCLUSIONS: The results of this critical review emphasise a lack of evidence and highlight the need for further evaluation research on this topic.

The impact and control of malignant catarrhal fever in Tanzania

Malignant Catarrhal Fever (MCF), an often-lethal infectious disease, presents as a variable complex of lesions in susceptible ungulate species. The disease is caused by a -herpesvirus following transmission from an inapparent carrier host. Two major epidemiological forms exist: wildebeest-associated MCF (WA-MCF), in which the virus is transmitted to susceptible species by wildebeest calves less than approximately four months of age, and sheepassociated MCF (SA-MCF) in which the virus is spread by sheep (primarily adolescents). Due to the lack of an in-vitro propagation system for the causative agent of the more economically significant SA-MCF, and with the expectation that cross-protective immunity may be provided, vaccine development has focused on the more easily propagated alcelaphine herpesvirus-1 (AlHV-1) that causes WA-MCF. In 2008 a direct viral challenge trial showed that a novel vaccine, employing an attenuated AlHV-1 (atAlHV-1) `C5000 virus strain, protected British Friesian-Holstein (FH) cattle against an intranasal challenge with virulent AlHV-1 `C5000 virus. For cattle keeping people living near wildebeest calving areas in sub-Saharan Africa an effective vaccine would have value as it would release them from the costly annual disease avoidance strategy of having to move their herds away from the oncoming wildebeest. On the other hand, an effective vaccine will release herd owners from the need to avoid MCF, allowing them to graze their cattle alongside wildebeest on the highly nutritious pastures of the calving areas. As such conservationists have raised concerns that the development of a vaccine might lead to detrimental grazing competition. The principle objective of this study was to test the novel vaccine on Tanzanian shorthorn zebu cross cattle (SZC).We did this firstly using a natural challenge field trial (Chapter Two) which demonstrated that immunisation with the atAlHV-1 vaccine was well tolerated and induced an oro-nasopharyngeal AlHV-1-specific and -neutralising antibody response. This resulted in an immunity in SZC cattle that was partially protective and reduced naturally transmitted infection by 56%. We also demonstrated that non-fatal infections occurred with a much higher frequency than previously thought. Because the calculated efficacy of the vaccine was less than that seen in British FH cattle we wanted to determine whether host factors, particular to SZC cattle, had impacted the outcomes of the field trial. To do this we repeated the 2008 direct viral challenge trial using SZC cattle (Chapter Four). During this trial we also investigated whether the recombinant bacterial flagellin monomer (FliC), when used as an adjuvant, might improve the vaccine’s efficacy. The findings from this trial indicated that direct challenge with pathogenic AlHV-1 is effective at inducing MCF in SZC cattle and that FliC is not an appropriate adjuvant for this vaccine. Furthermore, with less control group cattle dying of MCF than expected we speculate that SZC cattle may have a degree of resistance to MCF that affords them protection from infection and developing fatal disease. In Chapter Three we investigated aspects of the epidemiology of MCF, specifically whether wildebeest placenta, long implicated by Maasai cattle owners as a source of MCF, might play a role in viral transmission. Additionally, through comparative sequence analysis, at two specific genes (A9.5 and ORF50) of wild-type and atAlHV-1, we investigated whether the `C5000 strain, the source of which was taken from Africa more than 40 years ago, was appropriate for vaccine development. The detection of AlHV-1 virus in approximately 50% of placentae indicated that infection can occur in-utero and that this tissue might play a role in disease transmission. And, despite describing three new alleles of the A9.5 gene (supporting previous evidence that this gene is polymorphic and encodes a secretory protein with interleukin-4 as the major homologue), the observation that the most frequently detected haplotypes, in both wild-type and attenuated AlHV-1, were identical suggests that AlHV-1 has a slow molecular clock and that the attenuated strain was appropriate for vaccine development. In Chapter Five we present the first quantitative assessment of the annual MCF avoidance costs that Maasai pastoralists incur. In particular we estimated that as a result of MCF avoidance 64% of the total daily milk yield during the MCF season was not available to be used by the 81% of the family unit remaining at the permanent boma. This represents an upper-bound loss of approximately 8% of a household0s annual income. Despite these considerable losses we concluded that, given an incidence of fatal MCF in cattle living in wildebeest calving areas of 5% to 10%, if herd owners were to stop trying to avoid MCF by allowing their cattle to graze alongside wildebeest, any gains made through increased availability of milk, improved body condition and reduced energy demands would be offset by an increase in MCF-incidence. With the development of an effective vaccine, however, this alternative strategy might become optimal. The overall conclusion we draw therefore is that, despite the substantial costs incurred each year avoiding MCF, the partial protection afforded by the novel vaccine strategy is not sufficient to warrant a wholesale change in disease avoidance strategy. Nonetheless, even the partial protection provided by this vaccine could be of value to protect animals that cannot be moved, for example where some of the herd remain at the boma to provide milk or where land-use changes make traditional disease avoidance difficult. Furthermore, the vaccine may offer a feasible solution to some of the current land-use challenges and conflicts, providing a degree of protection to valuable livestock where avoidance strategies are not possible, but with less risk of precipitating the potentially damaging environmental consequences, such as overgrazing of highly nutritious seasonal pastures, that might result if herd owners decide they no longer need to avoid wildebeest.

The role of inflammation in vascular function and pregnancy outcome in the pregnant stroke prone spontaneously hypertensive rat

During pregnancy, the maternal cardiovascular system undergoes major adaptation. One of these changes is a 40-50 % increase in circulating blood volume which requires a systemic remodelling of the vasculature in order to regulate maternal blood pressure and maximise blood supply to the developing placenta and fetus. These changes are broadly conserved between humans and rats making them an appropriate pre-clinical model in which to study the underlying mechanisms of pregnancy-dependent cardiovascular remodelling. Whilst women are normally protected against cardiovascular disease; pregnancy marks a period of time where women are susceptible to cardiovascular complications. Cardiovascular disease is the leading cause of maternal mortality in the United Kingdom; in particular hypertensive conditions are among the most common complications of pregnancy. One of the main underlying pathologies of these pregnancy complications is thought to be a failure of the maternal cardiovascular system to adapt. The remodelling of the uterine arteries, which directly supply the maternal-fetal interface, is paramount to a healthy pregnancy. Failure of the uterine arteries to remodel sufficiently can result in a number of obstetric complications such as preeclampsia, fetal growth restriction and spontaneous pregnancy loss. At present, it is poorly understood whether this deficient vascular response is due to a predisposition from existing maternal cardiovascular risk factors, the physiological changes that occur during pregnancy or a combination of both. Previous work in our group employed the stroke prone spontaneously hypertensive rat (SHRSP) as a model to investigate pregnancy-dependent remodelling of the uterine arteries. The SHRSP develops hypertension from 6 weeks of age and can be contrasted with the control strain, the Wistar Kyoto (WKY) rat. The phenotype of the SHRSP is therefore reflective of the clinical situation of maternal chronic hypertension during pregnancy. We showed that the SHRSP exhibited a deficient uterine artery remodelling response with respect to both structure and function accompanied by a reduction in litter size relative to the WKY at gestational day (GD) 18. A previous intervention study using nifedipine in the SHRSP achieved successful blood pressure reduction from 6 weeks of age and throughout pregnancy; however uterine artery remodelling and litter size at GD18 was not improved. We concluded that the abnormal uterine artery remodelling present in the SHRSP was independent of chronic hypertension. From these findings, we hypothesised that the SHRSP could be a novel model of spontaneously deficient uterine artery remodelling in response to pregnancy which was underpinned by other as yet unidentified cardiovascular risk factors. In Chapter 1 of this thesis, I have characterised the maternal, placental and fetal phenotype in pregnant (GD18) SHRSP and WKY. The pregnant SHRSP exhibit features of left ventricular hypertrophy in response to pregnancy and altered expression of maternal plasma biomarkers which have been previously associated with hypertension in human pregnancy. I developed a protocol for accurate dissection of the rat uteroplacental unit using qPCR probes specific for each layer. This allowed me to make an accurate and specific statement about gene expression in the SHRSP GD18 placenta; where oxidative stress related gene markers were increased in the vascular compartments. The majority of SHRSP placenta presented at GD18 with a blackened ring which encircled the tissue. Further investigation of the placenta using western blot for caspase 3 cleavage determined that this was likely due to increased cell death in the SHRSP placenta. The SHRSP also presented with a loss of one particular placental cell type at GD18: the glycogen cells. These cells could have been the target of cell death in the SHRSP placenta or were utilised early in pregnancy as a source of energy due to the deficient uterine artery blood supply. Blastocyst implantation was not altered but resorption rate was increased between SHRSP and WKY; indicating that the reduction in litter size in the SHRSP was primarily due to late (>GD14) pregnancy loss. Fetal growth was not restricted in SHRSP which led to the conclusion that SHRSP sacrifice part of their litter to deliver a smaller number of healthier pups. Activation of the immune system is a common pathway that has been implicated in the development of both hypertension and adverse pregnancy outcome. In Chapter 2, I proposed that this may be a mechanism of interest in SHRSP pregnancy and measured the pro-inflammatory cytokine, TNFα, as a marker of inflammation in pregnant SHRSP and WKY and in the placentas from these animals. TNFα was up-regulated in maternal plasma and urine from the GD18 SHRSP. In addition, TNFα release was increased from the GD18 SHRSP placenta as was the expression of the pro-inflammatory TNFα receptor 1 (Tnfr1). In order to investigate whether this excess TNFα was detrimental to SHRSP pregnancy, a vehicle-controlled intervention study using etanercept (a monoclonal antibody which works as a TNFα antagonist) was carried out. Etanercept treatment at GD0, 6, 12 and 18 resulted in an improvement in pregnancy outcome in the SHRSP with an increased litter size and reduced resorption rate. Furthermore, there was an improved uterine artery function in GD18 SHRSP treated with etanercept which was associated with an improved uterine artery blood flow over the course of gestation. In Chapter 3, I sought to identify the source of this detrimental excess of TNFα by designing a panel for maternal leukocytes in the blood and placenta at GD18. A population of CD3- CD161+ cells, which are defined as rat natural killer (NK) cells, were increased in number in the SHRSP. Intracellular flow cytometry also identified this cell type as a source of excess TNFα in blood and placenta from pregnant SHRSP. I then went on to evaluate the effects of etanercept treatment on these CD3- CD161+ cells and showed that etanercept reduced the expression of CD161 and the cytotoxic molecule, granzyme B, in the NK cells. Thus, etanercept limits the cytotoxicity and potential damaging effect of these NK cells in the SHRSP placenta. Analysing the urinary peptidome has clinical potential to identify novel pathways involved with disease and/or to develop biomarker panels to aid and stratify diagnosis. In Chapter 4, I utilised the SHRSP as a pre-clinical model to identify novel urinary peptides associated with hypertensive pregnancy. Firstly, a characterisation study was carried out in the kidney of the WKY and SHRSP. Urine samples from WKY and SHRSP taken at pre-pregnancy, mid-pregnancy (GD12) and late pregnancy (GD18) were used in the peptidomic screen. In order to capture peptides which were markers of hypertensive pregnancy from the urinary peptidomic data, I focussed on those that were only changed in a strain dependent manner at GD12 and 18 and not pre-pregnancy. Peptide fragments from the uromodulin protein were identified from this analysis to be increased in pregnant SHRSP relative to pregnant WKY. This increase in uromodulin was validated at the SHRSP kidney level using qPCR. Uromodulin has previously been identified to be a candidate molecule involved in systemic arterial hypertension but not in hypertensive pregnancy thus is a promising target for further study. In summary, we have characterised the SHRSP as the first model of maternal chronic hypertension during pregnancy and identified that inflammation mediated by TNFα and NK cells plays a key role in the pathology. The evidence presented in this thesis establishes the SHRSP as a pre-clinical model for pregnancy research and can be continued into clinical studies in pregnant women with chronic hypertension which remains an area of unmet research need.