Orientador: Albina Messias de Almeida Milani Altemani / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-04T15:06:25Z (GMT). No. of bitstreams: 1 Brito_HugoLeitedeFarias_D.pdf: 985712 bytes, checksum: 049c9f97cfac78c5235143ee9925a67f (MD5) Previous issue date: 2005 / Resumo: A inflamação da vilosidade placentária, ou vilosite, pode ser causada por diversos agentes infecciosos, porém na maioria dos casos a etiologia é desconhecida. As vilosites estão associadas a aborto, malformações fetais, prematuridade e retardo do crescimento intra-uterino, que é a principal manifestação clínica nos casos de etiologia desconhecida. Estes casos têm sido explicados como o resultado de uma reação imune materna contra o tecido placentário ou causados por algum agente infeccioso não identificado e sem manifestação clínica materno-fetal. Não é possível distinguir, ao exame histológico, a vilosite de etiologia desconhecida (VED) de uma vilosite infecciosa, se nesta última não for identificado microorganismos no tecido ou sinais histológicos de infecção, tais como inclusões virais. O aspecto histológico é semelhante em ambos os grupos e na maioria dos casos a reação inflamatória está constituída por linfócitos e histiócitos. A presença de padrões imunofenotípicos específicos nos diferentes tipos de vilosite poderia auxiliar tanto no diagnóstico como na compreensão da patogênese dessas lesões placentárias. Foi estudada a composição do infiltrado inflamatório em 23 placentas com vilosite (oito por T. cruzi, cinco por T. gondii e oito de etiologia desconhecida), duas placentas com intervilosite pelo Paracoccidioides brasiliensis e 8 placentas controles sem inflamação, através da técnica imunoistoquímica avidina-biotina-peroxidase em cortes histológicos de material fixado em formalina e incluido em parafina. Os anticorpos pesquisados foram: UCHL1 (CD45RO), L26 (CD20), CD45RO/0PD4 (CD4), CD8, NK-like, M1 (CD15), Mac 387, HAM 56 (CD68) e proteína S-100. Em todos os casos e nos diferentes tipos de vilosite estudados a reação inflamatória estava predominantemente constituída por linfócitos T do subtipo CD8+ e histiócitos HAM 56+. Também foram identificados, em menor quantidade, linfócitos T CD4+, macrófagos MAC 387+, granulócitos, células S-100 + e escassas células NK. Os linfócitos B estavam ausentes ou eram menos do que 2% das células inflamatórias em todos os casos. Nas placentas com intervilosite por P. brasiliensis o infiltrado era composto por macrófagos Mac 387 + e granulócitos M1+. O estudo da composição do infiltrado inflamatório, por imunoistoquímica, não permite diferenciar VED de vilosite infecciosa. A presença de um mesmo perfil de células inflamatórias em ambos os grupos (infeccioso e VED) favorece a hipótese de que a VED seja causada por algum agente infeccioso não identificado, possivelmente viral. Também é possível que diferentes agentes etiológicos causem inflamação vilositária através do mesmo mecanismo patogênico, o qual envolve uma reação imune celular mediada por linfócitos T CD8+ e histiócitos / Abstract: Villitis is characterized by an inflammatory infiltrate within the villous stroma and can be caused by a large number of infectious agents, although most are of unknown etiology. Villitis, not rarely, is associated with intrauterine fetal death, abortion, malformations and fetal growth retardation. The latter has been the major clinical association of villitis of unknown etiology (VUE). Two hypotheses has been advocated to explain this lesion: a maternal immune attack against fetal tissue or an unidentified infection. Histology alone cannot distinguish VUE from an infectious villitis, unless microorganisms or viral inclusions are found in tissue. Both lesions are characterized by chronic inflammatory cells, mainly lymphocytes and macrophages, in the placental villous stroma. Granulomas and trophoblast damage, very typical of some infectious villitis, can also be a feature of VUE. Therefore, immunohistochemical phenotyping of the inflammatory cells could be of diagnostic value in villitis. There are few immunomorphological studies about the inflammatory cells in infectious villitis as well as in VUE. We studied the inflammatory cells by immunohistochemistry in 23 placentas with villitis (8 cases of Trypanosoma cruzi villitis, 5 cases of Toxoplasma gondii villitis and 8 cases of VUE). Two cases of P. brasiliensis intervillositis and 8 control placentas without inflammation were also analysed. Paraffin sections of all placentas were submitted for immunohistochemistry analysis according the avidin-biotin-peroxidase technique. Antibody panel consisted of UCHL1 (CD45RO), L26 (CD20), CD45RO/OPD4, CD8, NK-like, M1 (CD15), Mac387, HAM 56 (CD68) and S-100 protein. In all cases of villitis (infectious and of unknown etiology) the inflammatory infiltrate consisted mainly of HAM 56+ macrophages and T lymphocytes. Among T cells, CD8+ cells outnumbered CD4+ cells in all placentas. B lymphocytes were absent or very rare (<2%). A small number of Mac 387+ monocytes, NK cells and S-100+ cells were also detected. Paracoccidiodomycosis intervillositis consisted of Mac387+ histiocytes and M1+ granulocytes. Our findings showed that immunohistochemical study of the inflammatory cells cannot distinguish VUE from infectious villitis. The same cellular composition of the inflammatory infiltrate in the two studied groups (VUE and infectious villitis) favors the hypothesis that VUE could result from an infectious cause. In addition, this finding raises the possibility that different etiologic factors acts through a common pathway to cause villitis which is an inflammatory lesion mediated by CD8+ T lymphocytes and macrophages / Doutorado / Anatomia Patologica / Doutor em Ciências Médicas

Abstract Several in vitro methods using both human and animal tissues have been developed to study hepatic metabolism and placental transfer. The pressure to minimize animal studies has increased during the past few decades due to the public opinion and ethical considerations. However, these methods need further evaluation of their predictive power when applied in vivo. The aim of this work was to produce new information of the metabolism and transplacental passage of several anticonvulsants as well as to evaluate the usefulness of the placental perfusion method and several in vitro methods for analyzing metabolism in the prediction of clinical pharmacokinetics. Carbamazepine (CBZ) metabolism was studied using human and mouse liver microsomes, human hepatocytes, human liver slices and yeast cells expressing recombinant enzymes. All test systems predicted well the major metabolite carbamazepine-10,11-epoxide (CBZ-E). Also, minor metabolites were produced in slightly variable amounts in all systems except cells with recombinant enzymes. All human liver systems demonstrated that CYP3A4 is the principal CBZ metabolising enzyme. However, our results on CBZ-treated mice suggested that the metabolism of CBZ to CBZ-E is mainly mediated by CYP1A1 in C57/BL6 mice. Autoinduction of CBZ metabolism was seen in hepatocytes and in incubations using microsomes from CBZ-treated mice. Human liver and mouse liver microsomes metabolized oxcarbazepine (OCBZ) mainly to its active metabolite, 10-hydroxy-10,11-dihydro-carbamazepine (10-OH-CBZ). Also, 10,11-trans-dihydroxy-10,11-dihydro-carbamazepine (10,11-D) and an unknown metabolite were detected. Placental transfer of lamotrigine (LTG) and diazepam (DZP) was considerable in the human placental perfusion system, indicating marked fetal exposure in vivo. The OCBZ, 10-OH-CBZ and 10,11-D analyzed from maternal venous and cord blood also suggested significant fetal exposure. The placental perfusion system predicts well the transplacental passage of LTG and OCBZ and its major metabolite. However, in vivo cord blood concentrations of DZP are higher than maternal concentrations. Placental perfusion studies did not predict this. Still, even with its limitations, the human placental perfusion method provides information that can be used to evaluate the risk factors associated with drug use during pregnancy because understanding of specific transport characteristics is a good basis for rational risk assessment. In conclusion, all of the tested in vitro systems were useful in the prediction of at least some aspects of in vivo pharmacokinetics and metabolism, but validation and refinement are still essential, as is also the need to keep in mind the limitations characteristic of each in vitro method.

Abstract The biosynthesis and metabolism of sex steroids are controlled by a series of steroidogenic enzymes. In the placenta and the breast, 3β-hydroxysteroid dehydrogenase type 1 (3β-HSD1) is essential for the synthesis of all steroid hormones by catalyzing pregnenolone to progesterone (P) or dehydroepiandrosterone (DHEA) to androstenedione (A-dione). P450 aromatase (P450arom) converts androgens to estrogens and is therefore critical for estrogen production. 17β-hydroxysteroid dehydrogenases (17HSDs) are a group of enzymes responsible for the interconversion between low-activity 17-ketosteroids and high-activity 17β-hydroxysteroids, thus acting as key enzymes modulating the biosynthesis and metabolism of both estrogens and androgens. In situ hybridization assays showed that 3β-HSD1, P450arom and 17HSD1, 2, 5 and 7 are expressed in early and mid-gestation placentas. Abundant expressions of 3β-HSD1, P450arom and 17HSD1 were seen in syncytiotrophoblast (ST) cells. Signals of these three enzymes were also detected in some column cytotrophoblast (CCT) cells. 17HSD2 and 5 were located in intravillous stromal (IS) cells, whereas 17HSD7 mRNA was present in all types of placental cells. This suggests that the human placenta produces not only P and estrogens, but also androgens. Moreover, the placenta possesses a function, by the action of 17HSD2, to protect the fetus and the maternal body from excessive sex steroid influence. In tubal pregnancy, P450arom and 17HSD1 were found in ST cells, implying an estrogen biosynthesis mechanism similar to that in normal intrauterine pregnancy. In both JEG-3 choriocarcinoma cell line and cultured normal human cytotrophoblast (CTB) cells, retinoic acids were shown to promote the enzyme activity as well as mRNA expression of P450arom and 17HSD1, and hence their action on the biosynthesis of E2. The mRNA expressions of 17HSD1, 2 and 5 in 794 breast carcinoma specimens were analyzed and correlated with ERα, ERβ, PR, Ki67, c-erbB2 and clinical parameters. 17HSD1, 2 and 5 were detected in epithelial cells in normal and malignant breast tissues. In breast cancer specimens, the positive cases for 17HSD1, 2 and 5 were 16%, 25% and 65%, respectively. 17HSD1 was found to be an independent prognostic marker of the progression of breast cancer.

During normal placental development, a primitive vascular network develops through vasculogenesis and angiogenesis, and is then remodelled through maturation and regression. The mechanism behind this regression is unknown, but data from other systems suggests that it could be due to an endothelial-mesenchymal transition (EndMT). If this is the case, then dysregulated EndMT could lead to increased vascular regression, which could result in placental hypovascularisation. As the placental vasculature is the area of exchange between maternal and fetal circulations, a reduction in its surface area could result in fetal growth restriction (FGR). The hypothesis of this thesis is that EndMT occurs during normal placental development, but is increased during FGR and contributes to placental hypovascularisation. A primary cell model consisting of endothelial and mesenchymal cells was isolated from human first trimester placental villous stroma. These cells were shown to lose CD31 mRNA (n = 1-3) and protein (n = 15) over 4 passages, with no loss of cell viability (n = 8). EndMT-associated transcription factors were also present in these cells at all 4 passages (n = 2-4). When cells were isolated from this mixed cell model based on their CD31-positivity and examined immediately after isolation, a small proportion also expressed αSMA (n = 5). Co-expression of endothelial and mesenchymal markers suggests that an EndMT was occurring. After 24 hours in culture, the proportion of these cells expressing αSMA increased (n = 5), and some cells co-expressed vWF and αSMA, while others lost their CD31-positivity, indicating that these cells had undergone EndMT. Cells isolated based on their CD31-positivity were treated with factors shown to inhibit EndMT in other systems. However, culture with 10µM SB431542 (TGFβ receptor inhibitor; n = 6), 10µM Dorsomorphin (BMP receptor inhibitor; n = 3), or 0.1µM PDGFR-β Tyrosine Kinase Inhibitor IV (n = 3) did not inhibit gain of αSMA by these cells. Culture on Matrigel in endothelial growth medium containing VEGF and FGF also failed to stabilise the endothelial phenotype (n = 3). The possibility that EndMT occurs in placenta in vivo was examined; genes associated with EndMT were shown to be present in placenta (n = 5), and there was limited evidence of CD31 or vWF co-expression with αSMA in tissue. Preliminary evidence was obtained to suggest that expression of EndMT-associated genes was altered in FGR placentas compared to normal. In summary, the data presented in this thesis demonstrate that an EndMT occurs in primary placental microvascular endothelial cells in vitro. Furthermore, these studies provide evidence to suggest that this transition also occurs in vivo and could be altered in placentas from pregnancies complicated by FGR.

Advanced maternal age (AMA) is defined as childbearing in mothers ≥35 years of age and is becoming increasingly prevalent in high income countries. AMA has been associated with increased risk of adverse pregnancy outcomes, particularly stillbirth. Although AMA mothers have higher rates of chromosomal abnormalities and maternal co-morbidities, AMA remains an independent risk factor for stillbirth. Despite these findings, the etiology behind this increased risk is unknown. We hypothesise that an altered maternal environment, including increased oxidative stress and inflammation, due to ageing causes placental dysfunction which increases AMA mothers’ vulnerability to stillbirth. A holistic approach was applied to investigate placental dysfunction in AMA. Firstly, a systematic review and meta-analysis comprehensively reviewed existing data on AMA and associated adverse pregnancy outcomes. Secondly, Manchester Advanced Maternal Age Study (MAMAS), a multi-centre prospective observational cohort study, was conducted to investigate risk factors for composite adverse pregnancy outcome (CAPO) in AMA. MAMAS utilised both uni- and multivariate analysis on demographic and clinical data, and measuring biomarkers of ageing and placental dysfunction by ELISA in maternal circulation during the third trimester of pregnancy. Utero-placental dysfunction was directly investigated in uncomplicated AMA pregnancies by quantifying placental morphology, placental nutrient transport capabilities and both placental and maternal uterine vascular responses. Finally, a C57BL/6J murine model of AMA was developed and characterised to further investigate maternal age on pregnancy outcome and the role of the placenta. In the meta-analysis, maternal age was linearly associated with increased risk of stillbirth and other adverse outcomes strongly associated with placental dysfunction (fetal growth restriction, preeclampsia and placental abruption). In MAMAS, smoking status and primiparity were predictive of CAPO. After adjustment, AMA mothers had an odd ratio of 2.05-3.43 of CAPO compared to 20-30 year old mothers. AMA mothers showed evidence of increased oxidative stress and pro-inflammatory bias. AMA mothers who suffered CAPO showed reduced placental endocrine capacity seen in placental dysfunction. Placentas from uneventful AMA pregnancies showed evidence of accelerated ageing and placental adaptation with increased nutrient transport, increased placental weight but reduced efficiency, and altered vascular function. AMA mice showed many similar aspects to human AMA with increased fetal loss, fetal growth restriction and increased placental size. These studies provide robust evidence for increased incidence of adverse pregnancy outcome due to placental dysfunction in pregnancies of women of AMA. This finding requires the appropriate recognition in a clinical context, with a greater focus on personalised obstetric care in an attempt to reduce stillbirth rates in this high risk population. By optimising antenatal and obstetric care for AMA mothers, we could reduce stillbirth rates by 4.7% - the population attributable risk due to AMA. These studies highlight key areas of future research that will further understanding into stillbirth risk in AMA pregnancy, test predictive models and test therapies and clinical care interventions an ultimately improve pregnancy outcome in mothers of AMA.

Background: In addition to a diet including fortified dietary staples, the use of prenatal multivitamin supplements among women has been shown, in some cases, to lead to excessive micronutrient intake levels for nutrients such as folic acid (FA). It was therefore hypothesized that prenatal vitamin supplementation, in addition to a standard Canadian diet, would place pregnant Canadians at risk for excessive FA intake. With little available research on the potential negative impact of excess FA intake in pregnancy, it was further proposed that high concentrations of FA may adversely affect placental health and function. Thus, the aim of the current study was three-fold: 1) To determine micronutrient intake in a large Canadian cohort of pregnant women; 2) To determine the extent to which FA intake in this cohort may exceed the tolerable upper intake level (UL) after prenatal supplementation; and 3) To determine the effects of excessive FA exposure on placental health and function in vitro. Methodology: Second trimester 3-day food records of pregnant women (N=216) were analyzed for micronutrient intake using ESHA Food ProcessorTM. Nutrient intake values were compared to established Dietary Reference Intake (DRI) values. In a series of experiments, the effects of exogenous folic acid (2-4000 ng/ml) on placental health and function were examined in two placental cell lines [HTR-8/SVneo (N=3) and BeWo (N=3)], and a human placenta explant model (N=6). Following a 48-hour incubation period, the effects of excessive folic acid exposure on placenta cell proliferation, viability, and apoptosis were determined, along with evaluation of placenta cell function via cell invasion and B-hCG hormone release assays. Results: Through dietary sources alone, most pregnant women studied were consuming adequate levels of most micronutrients. However the majority of examined women (>50%) demonstrated a risk of dietary inadequacy for vitamin D, vitamin E, folate, and iron. In the examined cohort, 83% of study participants reported prenatal supplement usage. In vitro exposure of human placenta cells and explants to excessive FA concentrations resulted in no significant differences in cellular proliferation, apoptosis, invasion, or B-hCG hormone production. However, decreased cell viability was observed in BeWo cells at increased FA concentrations (200-2000 ng/mL). Conclusion: Food sources alone do not appear to provide women in Canada with adequate intake of all micronutrients recommended for a healthy pregnancy. Though a prenatal supplement containing FA may be necessary for most women, current FA levels in many prenatal supplements may lead to excessive FA intake above the established UL. Yet, as measured in this study, high FA concentrations do not seem to adversely affect most primary indicators of placental cell health or function.

The intrauterine environment plays an important role in fetal development and downstream health. Given the rise in maternal obesity and the incidence of babies being born large-for-gestational-age, research is needed exploring the mechanisms through which maternal obesity and health behaviours affect the delivery of nutrients to the fetus. This thesis includes three manuscripts in the pursuit of two objectives: 1) To determine whether there are changes in placenta nutrient transport-related gene expression in response to obesity, excess gestational weight gain, and variations physical activity and diet, and 2) To examine whether the Pregnancy Physical Activity Questionnaire is a reliable estimate of physical activity during the second trimester of pregnancy. In manuscript 1, we found that maternal obesity was not related to placenta nutrient transport-related gene expression, with the exception of lower placental mTOR expression in obese women who delivered male offspring, however, gestational weight gain was related to the gene expression of key proteins in the placenta. In manuscript 2, it was determined that the Pregnancy Physical Activity Questionnaire significantly overestimates physical activity and is not correlated with direct measures of activity and thus should not be used in future research. In manuscript 3, we found that physical activity and diet modify the expression of the genes involved in placenta nutrient transport. Meeting physical activity guidelines was associated with lower expression of a fatty acid transporter and higher expression of an amino acid transporter, while sugar intake was related to the expression of a glucose transporter. Together, the studies that make up this thesis suggest that there are numerous factors that may be contributing to placenta nutrient transport-related gene expression in humans and that future research on the placenta ought to include direct measures of physical activity and maternal diet, as well as account for gestational weight gain with respect to the guidelines and fetal sex.

Objectives: Human Endogenous Retroviruses (HERVs) were originally derived from germ cell infection by exogenous retroviruses and comprise around eight per cent of the human genome. HERVs are highly expressed in the placenta, where HERV-W (syncytin 1) has been demonstrated to perform a fusogenic function. Due to their retroviral origin, placental syncytin 1 has been suggested to also be involved in modulating the maternal immune system. The placenta constantly sheds microvesicles (MV) into the maternal circulation, demonstrated to cause innate immune cell activation associated with normal pregnancy. In pre-eclampsia, there is both increased placental MV shedding and a heightened pro-inflammatory immune response. It was therefore hypothesised that HERVs shed via placental MV play a role in feto-maternal immune interactions and thus may be an important factor in the pathogenesis of preeclampsia (PE). More specifically, it was hypothesised that syncytin 1-positive MV activate monocytes through toll-like receptor 4 (TLR-4). The aim of this study was to determine if syncytin 1 is released from the placenta via MV and exerts an immunological effect. Methods: HERV mRNA and protein expression was measured in placenta and the BeWo choriocarcinoma cell line by qPCR, western blotting (WB) and immunostaining. Glycosylation of syncytin 1 protein was determined by PNGase F treatment followed by WB. MV shed by first trimester, term normal and PE placental explants as well as BeWo cells were isolated by ultracentrifugation. Morphology of these microvesicles was examined by electron microscopy. Syncytin 1 protein and RNA was detected in microvesicles by WB and PCR. Activation and priming of PBMCs to respond to lipopolysaccharide (LPS) by syncytin 1-positive MV and recombinant syncytin 1 was examined through cytokine production by ELISA and multiplex. Antagonism of TLR-4 by LPS-RS was used to determine involvement of the receptor. The role of syncytin 1 in MV activation was examined by siRNA knockdown. Results: HERVs are highly expressed in placental tissue. Syncytin 1 is a glycosylated protein and its expression is altered in PE. MV shed from the BeWo choriocarcinoma cell line and from first trimester and term placental explants, express HERV protein and RNA. Syncytin 1 positive MV and recombinant syncytin protein cause activation of PBMCs. Greatest activation is stimulated by PE MV. Normal MV exhibit a neutral or suppressive effect on subsequent LPS challenge to PBMCs. PE MV exacerbate the response to LPS. Antagonism of TLR-4 on PBMCs and knockdown of syncytin 1 content in MV reduces activation by placental MV.Conclusions: The findings of this thesis suggest that syncytin 1 protein expressed by the placenta is shed into the maternal circulation via MV, and can activate immune cells through TLR-4. Syncytin 1-positive microvesicles may play a role in endotoxin tolerance of innate immune cells in pregnancy. The increased activation by PE MV implies that in addition to the increased microvesicle load in this pathology, a factor intrinsic to PE MV is responsible for increased inflammation. These studies implicate microvesicle-bound syncytin 1 in the regulation of immunotolerance during pregnancy.

Pregnancies complicated with diabetes mellitus (DM) are associated with poor maternal and fetal outcomes, such as birth trauma, fetal overgrowth (macrosomia) and programming of the fetus to develop metabolic syndrome in adult life. Maternal hyperglycemia is thought to contribute to fetal macrosomia, however the role of the placenta in these pregnancies is incompletely understood, therefore we aimed to investigate the specific consequences of high glucose on placental metabolism. To achieve this aim an in vitro model of placental exposure to high glucose was developed. This model was used with the aim of analysing how high glucose alters the transcriptome and metabolome of these cells, using a systems biology approach to identify candidate functional pathways which may be altered in placenta as a result of hyperglycemia. These candidate functional pathways were validated in an ex vivo model of placenta exposed to high glucose and in placental tissue from pregnancies complicated by DM. A trophoblast cell line (BeWo) was cultured in low (5 mM) and high (12 mM or 25 mM) D-glucose conditions for 48 hours. Transcriptomic and metabolomic analysis of these cells was performed using microarrays, and gas- and liquid-chromatography-mass spectrometry, respectively. Transcript and metabolite changes were independently analysed and integrated, using network analysis. From the integrated analysis of the ‘omic datasets, β-fatty acid oxidation (β-FAO), purine metabolism, phosphatidylinositol/PI3K phosphate pathway and lipid metabolism, were identified as candidates for further study. Changes within the PI3K pathway and lipid metabolism/β-fatty acid oxidation were validated in an ex vivo placental explant model of high glucose and in placental tissue from women with DM, compared to uncomplicated pregnancies. mRNA, protein expression and protein activation of key molecules within the PI3K pathway were not significantly altered in placenta as a response of high glucose ex vivo or DM in vivo. The second candidate functional pathway, lipid metabolism, has previously been implicated in association with placental dysfunction in pregnancies complicated by DM. Placental fatty acid transporter and lipase protein expression, as well as, relative abundance of different fatty acids were unaltered in response to high glucose or DM. High glucose levels increased triglyceride levels within the placenta, indicating reduced rates of β-FAO. The effect of high glucose could be ameliorated using a PPARα agonist. This may provide a novel therapeutic intervention to prevent excess esterification of fatty acids to triglycerides in maternal diabetes, which may in turn influence fetal growth. This study illustrates how a systems biology approach can be used to identify novel candidate functional pathways that are altered within the trophoblast in response to high glucose. Thus, improving understanding of placental dysfunction in these pregnancies and providing novel candidate pathways for future study, which may represent potential therapeutic targets for intervention of fetal macrosomia in pregnancies complicated by DM.

Made available in DSpace on 2014-06-12T23:01:28Z (GMT). No. of bitstreams: 2 arquivo4245_1.pdf: 2575434 bytes, checksum: 70b9a52625b7afbaebc84673f937aff0 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2009 / A planta Petiveria alliacea L. é usada na medicina popular em infusões ou misturada com outras plantas, aplicadas em fricções contra dores articulares e reumáticas. Os dados farmacológicos dessa planta são muito variados, servindo como antinoceptiva, anticonvulsante, analgésica, antiinflamatória, hipoglicemiante, antifúngica, vermífugo, gastroprotetora, antitumoral, além de atividade anti-mitótica. Estudos demonstraram que a aplicação de diferentes doses de extratos hidroalcoólico de P. alliacea, em ratas, no terceiro ou no quinto dia de gestação possui efeito zigotóxico e abortivo. Assim, o presente estudo teve o objetivo avaliar o efeito de extratos hidroalcoólico da raiz de P. alliacea, sobre a interação blastocisto e endométrio em ratas. Para realização do experimento foram utilizadas 30 ratas albinas (Rattus norvegicus albinus) da linhagem Wistar, com 90 dias de idade, pesando aproximadamente 200g, provenientes do Biotério do Departamento de Morfologia e Fisiologia Animal da UFRPE. As fêmeas foram acasaladas e divididas em seis grupos: Grupos I e III - ratas tratadas com placebo no 50 dia de prenhez e sacrificadas no 70 dia e 14° dia (controle), respectivamente; Grupo II e IV - ratas tratadas com extrato hidroalcólico de raiz P. alliacea no 50 dia de prenhez e sacrificadas no 70 dia e 14° dia, respectivamente; Grupos V e VI- Neonatos oriundos de matrizes tratadas com placebo e extrato no 5° dia de prenhez, respectivamente. O extrato foi administrado por via oral (gavagem) na dosagem de 18mg/Kg. Os sítios de implantação e as placentas foram coletados, fixados em líquido de Bouin e processados para inclusão em paraplast . Os cortes obtidos foram submetidos à técnica de coloração pela hematoxilina - eosina (H. E). Os resultados mostraram que o extrato hidroalcoólico da raiz de P. alliacea ocasiona redução no número de sítios implantados; promove um menor desenvolvimento desses sítios, porém não ocasiona alterações histológicas. Com relação à morfologia placentária não houve alterações significativas, bem como na análise macroscópica dos neonatos não se observou alterações no número de nascidos, no comprimento e peso dos mesmos. Esses resultados sugerem que o extrato hidroalcoólico da raiz de P. alliacea na dosagem de 18mg/Kg/animal, administrado em ratas, no quinto dia de prenhez, produz apenas um retardo no processo de implantação