Ana Carolina Palei

Hemodynamic Benefits of Matrix Metalloproteinase-9 Inhibition by Doxycycline During Experimental Acute Pulmonary Embolism:

The authors examined whether acute pulmonary embolism (APE) increases lung matrix metalloproteinase (MMP)-2 and MMP-9 activities and whether inhibition of MMPs with doxycycline attenuates the hemodynamic changes associated with APE. Anesthetized male Wistar rats were monitored for mean arterial blood pressure (MAP) and heart rate (HR). Rats in the control group (n=5) received only saline IV; rats in the embolism (Emb) group (n=8) received saline IV followed 10 minutes later by an injection of Sephadex microspheres (9 mg/kg) IV; rats in the doxycycline (Doxy) group (n=4) received only doxycycline (30 mg/kg) IV, followed 10 minutes later by an injection of saline IV; rats in the Doxy + Emb group (n=8) received the same dose of doxycycline followed 10 minutes later by the same amount of microspheres described above. Lung samples were homogenized and assayed by SDS-polyacrilamide gel electrophoresis gelatin zymography to evaluate lung MMP-2 and MMP-9 activities. Saline or doxycycline produced no significant changes in MAP, HR, and in MMP-2 and MMP-9 activities. Conversely, lung embolization significantly reduced MAP by >32 mm Hg and HR by >90 bpm for more than 60 minutes, and increased MMP-9 activity by 43% (all p<0.05). No significant differences were observed in MMP-2 activity. However, lung embolization produced only transient hypotension in rats pretreated with doxycycline. In this group, MAP returned to baseline values 5 to 10 minutes after embolization. In addition, pretreatment with doxycycline blunted the increase in lung MMP-9 activity after lung embolization (p<0.05). This study demonstrates for the first time that MMP-9 inhibition with doxycycline attenuates APE-induced hemodynamic changes in the animal model examined. These findings indicate that MMP-9 activation plays a role in the pathophysiology of APE and suggest that pharmacologic strategies targeting specific MMPs with selective inhibitors may prevent the detrimental acute hemodynamic consequences of APE.

Tissue inhibitor of matrix metalloproteinase-1 polymorphism, plasma TIMP-1 levels, and antihypertensive therapy responsiveness in hypertensive disorders of pregnancy

Tissue inhibitor of metalloproteinase (TIMP)-1 is a major endogenous inhibitor of matrix metalloproteinase (MMP)-9, which may affect the responsiveness to therapy in hypertensive disorders of pregnancy. We examined whether TIMP-1 polymorphism (g.–9830T>G, rs2070584) modifies plasma MMP-9 and TIMP-1 levels and the response to antihypertensive therapy in 596 pregnant: 206 patients with preeclampsia (PE), 183 patients with gestational hypertension (GH) and 207 healthy pregnant controls. We also studied the TIMP-3 polymorphism (g.–1296T>C, rs9619311). Plasma MMP-9 and TIMP-1 levels were measured by ELISA. GH patients with the GG genotype for the TIMP-1 polymorphism had lower MMP-9 levels and MMP-9/TIMP-1 ratios than those with the TT genotype. PE patients with the TG genotype had higher TIMP-1 levels. The G allele and the GG genotype were associated with PE and responsiveness to antihypertensive therapy in PE, but not in GH. Our results suggest that the TIMP-1 g.–9830T>G polymorphism not only promotes PE but also decreases the responses to antihypertensive therapy.

Functional MMP-9 polymorphisms modulate plasma MMP-9 levels in multiple sclerosis patients.

We have described that MMP-9 C(-1562)T and (CA)(n) polymorphisms contribute to multiple sclerosis (MS). Here, we evaluate whether plasma MMP-9 levels are related to disease severity, drug therapy resistance and polymorphisms. For sub-study 1, 36 patients with MS and 35 controls were recruited. For sub-study 2, 88 individuals (53 patients and 35 controls) were included in a cross-sectional analysis. MS patients presented higher MMP-9 activity (1.4±0.18 versus 0.93±0.18A.U. for control, P<0.05). Drug-therapy resistant individuals exhibited increased MMP-9 activity (1.96±0.25 versus 1.21±0.09A.U. for non-resistant patients). EDSS score was also related to MMP-9 levels. The CT+TT and HH genotypes had higher MMP-9 levels as compared to patients carrying the CC and LL. Drug therapy resistance, disease severity, MMP-9 plasma activity and polymorphisms are associated with MS.

Gene–gene interactions in the NAMPT pathway, plasma visfatin/NAMPT levels, and antihypertensive therapy responsiveness in hypertensive disorders of pregnancy

Nicotinamide phosphorybosil transferase (NAMPT) polymorphisms affect visfatin/NAMPT levels and may affect the responsiveness to therapy in hypertensive disorders of pregnancy. We examined whether NAMPT polymorphisms (rs1319501 T>C and rs3801266 A>G), or haplotypes, and gene–gene interactions in the NAMPT pathway affect plasma visfatin/NAMPT levels and the response to antihypertensive therapy in 205 patients with preeclampsia (PE) and 174 patients with gestational hypertension. We also studied 207 healthy pregnant controls. Plasma visfatin/NAMPT levels were measured by ELISA. Non-responsive PE patients with the TC+CC genotypes for the rs1319501 T>C, and with the AG+GG genotypes for the rs3801266 A>G polymorphism had lower and higher visfatin/NAMPT levels, respectively. The ‘C, A’ haplotype was associated with response to antihypertensive therapy, and with lower visfatin/NAMPT levels in PE. Interactions among NAMPT, TIMP-1 and MMP-2 genotypes were associated with PE and with lack of response to antihypertensive therapy in PE. Our results suggest that NAMPT polymorphisms affect plasma visfatin/NAMPT levels in nonresponsive PE patients, and that gene–gene interactions in the NAMPT pathway not only promote PE but also decrease the response to antihypertensive therapy in PE.

PP002. Study of polymorphisms of the adiponectin gene in women with gestational hypertension and preeclampsia

INTRODUCTION Adiponectin is involved in energy homeostasis by regulating glucose and lipid metabolism. Additionally, it presents anti-inflammatory and anti-atherosclerotic functions. Polymorphisms in adiponectin gene (ADIPOQ) can modulate the concentrations of adiponectin. The influence of these polymorphisms on the development of gestational hypertension (GH) and preeclampsia (PE) is unknown. OBJECTIVES The aim of this work was to examine the influence of polymorphisms in the gene ADIPOQ on the development of gestational hypertension and preeclampsia. METHODS PATIENTS AND METHODS We studied 401 pregnant women: 161 healthy pregnant (HP), 113 pregnant with gestational hypertension (GH) and 127 pregnant with preeclampsia (PE). Polymorphisms ADIPOQ -11391G>A (rs17300539), -11377C>G (rs266729), 45T>G (rs2241766) and 276G>T (rs1501299) were genotyped by allelic discrimination by PCR in real time. Haplotypes were inferred using the PHASE 2.1 program. RESULTS There were no statistically significant differences in allele and genotype frequencies of the polymorphisms studied. In the analysis of haplotypes, we observed small differences in haplotype frequencies between groups, however, none of these differences was statistically significant (P>0.05). CONCLUSION We found no association between the genotypic and allelic variants of the ADIPOQ gene polymorphisms with the development of gestational hypertension and preeclampsia.

Assessment of nitrite oxide and maternal–fetal Doppler parameters during pregnancy

Abstract Objective: The objective was to evaluate and compare the whole blood nitrite concentration in the three trimesters of pregnancy. Additionally, we investigate whether there is any relation between nitrite concentrations and Doppler ultrasound analysis of some maternal and fetal vessels. Methods: Thirty-three healthy pregnant women were examined at the first (11–14 weeks), second (20–24 weeks) and third trimester (34–36 weeks) of pregnancy. In the three exams, we determined the maternal whole blood nitrite concentration and uterine arteries Doppler analysis to determine pulsatility index (PI), and resistance index (RI). In the second and third trimester we also performed fetal umbilical and middle cerebral arteries PI and RI. We compared the concentrations of nitrite in three trimesters and correlated with Doppler parameters. Results: No difference was observed in the whole blood nitrite concentrations across trimesters: 151.70 ± 77.90 nmol/ml, 142.10 ± 73.50 nmol/ml and 147.10 ± 87.30 nmol/ml; first, second and third trimesters, respectively. We found no difference in correlation between whole blood nitrite concentration and Doppler parameters from the evaluated vessels. Conclusions: In healthy pregnant women, the nitrite concentrations did not change across gestational trimesters and there was also no strong correlation with Doppler impedance indices from maternal uterine arteries and fetal umbilical and middle cerebral arteries.

PP070. Maternal flow-mediated dilation and nitrite concentration during third trimester of pregnancy and postpartum period.

INTRODUCTION The vascular endothelium is thought to be responsible for cardiovascular adaptations in gestation, such as the decrease in peripheral vascular resistance and the decrease in arterial pressure. There is an increase of nitric oxide (NO) serum levels in normal gestation due to an increment in the activity of the enzyme endothelial nitric oxide synthase (eNOS). OBJECTIVES To compare maternal flow-mediated dilation of the brachial artery (FMD) and the nitrite concentration between the third trimester of pregnancy and postpartum period. Additionally we want to evaluate whether FMD correlates with nitrite concentration. METHODS Eligibility criteria were healthy pregnant women with single fetus, gestational age greater than 28 weeks, nonsmokers, and without personal or family history of vascular disease. Each pregnant woman was examined in the third trimester of pregnancy (3(rd)T) and between 8 and 12 weeks postpartum (PP) to evaluate FMD and nitrite concentrations in the whole blood. We excluded women who were not examined in both periods. We compared the values between the two periods using paired t tests. The correlation between FMD and nitrite concentration was examined by Pearson correlation coefficient. Significance level was set at p<0.05. RESULTS 42 pregnant women were invited for the study. 35 healthy women were elected and 7 of them were excluded for not attending the postpartum evaluation. We found a trend of decreased FMD in the PP period (10.39±5.57 % vs. 8.42±4.21 %, p=0.11; 3(rd)T vs. PP respectively). No significant change was observed in the nitrite concentration (257.41±122.95nmol/L vs.237.16±90.01nmol/L, p=0.28). We did not observe significant correlation between FMD and nitrite during 3(rd)T (r=-0.13, p=0.50) or PP (r=0.14, p=0.48). CONCLUSION Although our sample size did not permit sufficient precision, FMD seems to decrease between the third trimester and postpartum period. Nitrite concentration did not change between the third trimester of pregnancy and the postpartum period, and it was not correlated to FMD. Studies evaluating larger samples are necessary to confirm these findings.

PP071. Evaluation of maternal–fetal doppler parameters and of whole blood nitrite throughout gestation

INTRODUCTION The Doppler method is extensively applied today for the evaluation of pregnancies with involvement of the uteroplacental blood flow. Although increased nitric oxide (NO) formation plays an important role in regulation of systemic vascular resistance during pregnancy, growing evidence indicates that reduced NO formation is associated with hypertensive disorders of pregnancy, especially preeclampsia. OBJECTIVES The studies were to assess the maternal and fetal Doppler parameters and to determine the whole blood nitrite levels during pregnancy. METHODS Thirty-three healthy pregnant women were evaluated during the first (11-14 weeks), second (20-24 weeks) and third trimesters (34-36 weeks) of pregnancy. The maternal (uterine arteries) and fetal (cerebral and umbilical arteries) vessels were evaluated by Doppler velocimetry. venous blood was collected(15mL) for the determination of plasma nitrite by chemiluminescence. RESULTS Regarding the Doppler parameters of the uterine arteries the mean pulsatility index was 1.73, 1.06 and 0.73 in the first, second and third trimesters of pregnancy, respectively. Fetal Doppler showed a mean resistance index of 0.82 and 0.81 for the middle cerebral artery, 0.73 and 0.60 for the umbilical artery in the second and third trimesters, respectively. The mean plasma nitrite concentration was 189.10, 178.28 and 199.57 nmol/ml in the first, second and third trimesters of pregnancy, respectively. CONCLUSION The study demonstrated that a fall in flow resistance occurs in the uteroplacental vessels without changes in plasma nitrite concentrations during pregnancy.