Abstract 037: Exaggerated Placental Ischemia-induced Hypertension in Endothelin Receptor Type B (ETB)-deficient Pregnant Rats s Independent of Increased sFlt-1 or ROS Levels

Hypertension ◽  
2017 ◽  
Vol 70 (suppl_1) ◽  
Author(s):  
Frank T Spradley
Keyword(s):  
Blood Pressure ◽  
Acute Hypoxia ◽  
Pressure Control ◽  
Normal Pregnancy ◽  
Endothelin Receptor ◽  
Maternal Circulation ◽  
Pregnant Rats ◽  
Uterine Perfusion ◽  
Placental Ischemia ◽  
In Pregnancy

While the pathogenesis of preeclampsia is not fully understood, studies implicate placental ischemia. Reduced uterine perfusion pressure (RUPP)-induced placental ischemia/hypoxia in animal models stimulates release of factors like antiangiogenic sFlt-1 into the maternal circulation increasing vascular-renal ET-1. ET-1 promotes hypertension via reactive oxygen species (ROS). Blockade of vasoconstrictive ETA abolishes RUPP hypertension. Deficiency of vasodilatory ETB in rats leads to increased blood pressure in pregnancy. While ETB deficiency markedly enhances RUPP hypertension, it is unknown if there is exaggerated RUPP-induced sFlt-1, ET-1 or ROS levels in ETB-def rats. The hypothesis was tested that placental ischemia/hypoxia-induced release of sFlt-1 and circulating ET-1 and ROS are greater in ETB-def rats. Eighteen-week-old ETB-def and transgenic (Tg) control pregnant rats were generated with Wistar Hannover males. RUPP or Sham surgeries were on gestational day 14 and assessment of plasmas and placentas at day 19. RUPP increased placental sFlt-1 (pg/mg) similarly in RUPP ETB-def (781±113, N=5) vs Sham ETB-def (573±54, N=12) and RUPP Tg (631±62, N=5) vs Sham Tg (547±31, N=12) (P<0.05). In placental explant cultures, acute hypoxia (48 h 1% O2 vs normoxia 6% O2) stimulated a comparable release of sFlt-1 (pg/mg) in Sham ETB-def (2577±135 vs 2070±78) and Sham Tg (3208±318 vs 2553±107) (P<0.05). Unexpectedly, plasma sFlt-1 (pg/mL) was lower in RUPP ETB-def (153±48) vs Sham ETB-def (476±125) and RUPP Tg (238±32) vs Sham Tg (463±102) (P<0.05). Plasma ET-1 (fmol/L) was exaggerated in RUPP ETB-def (954±70) and greater in Sham ETB-def (735±43) vs RUPP Tg (122±14) or Sham Tg (142±41) (P<0.05). Plasma H2O2 (umol/L) was not exaggerated in RUPP ETB-def (5.4±1.2) or RUPP Tg (4.0±0.5) but was greater (P<0.05) in Sham ETB-def (6.2±0.3) vs Sham Tg (3.6±0.3). In conclusion, these data suggest in 1) normal pregnancy, ETB is crucial for blood pressure control by regulating bioavailable ET-1 to prevent ROS production and 2) placental ischemia, ETB reduces excess ET-1 to buffer hypertension independently of sFlt-1 or ROS. These data support ETB physiology as important in controlling blood pressure in pregnancy and its loss in mediating hypertension in preeclampsia.

scholarly journals Melanocortin-4 Receptor Deficiency Attenuates Placental Ischemia-Induced Hypertension in Pregnant Rats

Hypertension ◽  
2019 ◽  
Vol 73 (1) ◽  
pp. 162-170 ◽  
Author(s):  
Frank T. Spradley ◽  
Ana C. Palei ◽  
Christopher D. Anderson ◽  
Joey P. Granger
Keyword(s):  
Blood Pressure ◽  
Nervous System ◽  
Perfusion Pressure ◽  
Wild Type ◽  
Pregnant Rats ◽  
Melanocortin 4 Receptor ◽  
Induced Hypertension ◽  
Sympathetic Nervous ◽  
Uterine Perfusion ◽  
Placental Ischemia

Preeclampsia is a pregnancy-specific disorder of new-onset hypertension linked to placental ischemia. While obesity is a major risk factor for preeclampsia, not all obese pregnant women develop pregnancy-induced hypertension or preeclampsia. Previously, we reported that placental ischemia-induced hypertension is dependent upon intact signaling of the sympathetic nervous system. Moreover, in various models of obesity, blockade of MC4R (melanocortin-4 receptor) signaling protects against the development of hypertension via suppression of the sympathetic nervous system. Less is known about this pathway during obese pregnancy. Although blockade of MC4R may lead to increased body weight during pregnancy, we tested the hypothesis that placental ischemia-induced hypertension is attenuated in obese MC4R-deficient pregnant rats. On gestational day 14, MC4R wild-type or heterozygous-deficient (MC4R-def) rats were subjected to chronic placental ischemia via the reduced uterine perfusion pressure procedure or Sham surgery then examined on gestational day 19. In Sham MC4R-def versus Sham wild-type pregnant rats, there was increased body weight, fat mass, and circulating leptin levels but they had similar fetus weights. Reduced uterine perfusion pressure reduced fetus weights in both strains. Reduced uterine perfusion pressure increased blood pressure in wild-type rats but this response was significantly attenuated in MC4R-def rats, although blood pressure was elevated in Sham MC4R-def over Sham wild-type. These data indicate that while obese MC4R-def pregnant rats have higher blood pressure during pregnancy, placental ischemia-induced hypertension is attenuated in obese MC4R-def pregnant rats. Thus, obese women with abnormal MC4R signaling may be less susceptible to the development of placental ischemia-induced hypertension.

Abstract 625: Hypoxia-Induced sFlt-1 Production is Enhanced in Placental Villi from Obese MC4R Deficient Rats

Hypertension ◽  
2013 ◽  
Vol 62 (suppl_1) ◽  
Author(s):  
Ana C Palei ◽  
Frank T Spradley ◽  
Joey P Granger
Keyword(s):  
Endothelial Dysfunction ◽  
Normal Pregnancy ◽  
Maternal Circulation ◽  
Pregnant Rats ◽  
Melanocortin 4 Receptor ◽  
Placental Villi ◽  
Obese Rats ◽  
The Face ◽  
Placental Ischemia

Although the etiology of preeclampsia (PE) remains unclear, evidence indicates that impaired cytotrophoblast invasion followed by placental ischemia/hypoxia promotes the release of placental anti-angiogenic factors, such as soluble fms-like tyrosine kinase-1 (sFlt-1), into the maternal circulation. sFlt-1 blocks the pro-angiogenic actions of vascular endothelial growth factor to elicit maternal endothelial dysfunction and ultimately hypertension and proteinuria. Moreover, a leading risk factor for PE is obesity; however, the mechanisms whereby obesity increases the risk for developing PE are unknown. Our aim was to evaluate circulating and placental sFlt-1 levels in a genetic rodent model of obesity, the melanocortin-4 receptor deficient rat (MC4R+/-). Additionally, we examined the effect of obesity on hypoxia-induced sFlt-1 production in placental villous explants. At gestational day 19, body weight (357±5 vs. 331±11 g) and visceral fat weight (15.3±0.4 vs. 9.2±0.4 g) were higher in MC4R+/- obese pregnant rats (N=7) over MC4R+/+ lean pregnant rats (N=7), whereas mean arterial pressure was similar between groups (MC4R+/-: 110±4 vs. MC4R+/+: 102±2 mmHg). The levels of sFlt-1 in plasma (MC4R+/+: 228±75 vs. MC4R+/+: 141±34 pg/mL) and whole placenta (MC4R+/-: 0.86±0.06 vs. MC4R+/+: 0.82±0.04 pg/mg) were comparable between groups. Similarly, there was no difference in sFlt-1 secretion from 48 h cultures of placental villi explanted from MC4R+/- (1969±176 pg/mg) vs. MC4R+/+ (1408±188 pg/mg) under normoxic conditions (6% oxygen). However, in the face of hypoxia (1% oxygen), there was more pronounced sFlt-1 secretion from MC4R+/- obese rats than MC4R+/+ lean counterparts (2160±233 vs. 1311±120 pg/mg, respectively; P<0.05). In conclusion, we found that sFlt-1 levels were not disrupted in obese pregnant rats during normal pregnancy; however, in vitro studies with placental villi from obese rats showed enhanced hypoxia-induced sFlt-1 secretion. Together these findings suggest that placental ischemia-induced endothelial dysfunction and hypertension may be exaggerated by obesity.

scholarly journals A model of preeclampsia in rats: the reduced uterine perfusion pressure (RUPP) model

2012 ◽  
Vol 303 (1) ◽  
pp. H1-H8 ◽  
Author(s):  
Jing Li ◽  
Babbette LaMarca ◽  
Jane F. Reckelhoff
Keyword(s):  
Intrauterine Growth Restriction ◽  
Perfusion Pressure ◽  
Trophoblast Invasion ◽  
Maternal Circulation ◽  
Pregnant Rats ◽  
Renal Vasoconstriction ◽  
Uterine Perfusion ◽  
Placental Ischemia ◽  
And Oxidative Stress ◽  
New Onset

Preeclampsia is defined as new-onset hypertension with proteinuria after 20 wk gestation and is hypothesized to be due to shallow trophoblast invasion in the spiral arteries thus resulting in progressive placental ischemia as the fetus grows. Many animal models have been developed that mimic changes in maternal circulation or immune function associated with preeclampsia. The model of reduced uterine perfusion pressure in pregnant rats closely mimics the hypertension, immune system abnormalities, systemic and renal vasoconstriction, and oxidative stress in the mother, and intrauterine growth restriction found in the offspring. The model has been successfully used in many species; however, rat and primate are the most consistent in comparison of characteristics with human preeclampsia. The model suffers, however, from lack of the ability to study the mechanisms responsible for abnormal placentation that ultimately leads to placental ischemia. Despite this limitation, the model is excellent for studying the consequences of reduced uterine blood flow as it mimics many of the salient features of preeclampsia during the last weeks of gestation in humans. This review discusses these features.

scholarly journals Elastin-Like Polypeptide: VEGF-B Fusion Protein for Treatment of Preeclampsia

Hypertension ◽  
2021 ◽  
Author(s):  
Jamarius P. Waller ◽  
John Aaron Howell ◽  
Hali Peterson ◽  
Eric M. George ◽  
Gene L. Bidwell
Keyword(s):  
Blood Pressure ◽  
Blood Pressure Reduction ◽  
Subcutaneous Administration ◽  
Growth Factor Receptor ◽  
Endothelial Cell Proliferation ◽  
Tyrosine Kinase Receptor ◽  
Pregnant Rats ◽  
Uterine Perfusion ◽  
Placental Ischemia

Preeclampsia is characterized by the development of elevated blood pressure during the second and third trimesters of pregnancy that is accompanied by end organ dysfunction. The pathogenesis of preeclampsia is multifactorial but is commonly characterized by endothelial dysfunction and the overproduction of antiangiogenic factors, including the soluble VEGF (vascular endothelial growth factor) receptor sFlt-1 (soluble Fms-like tyrosine kinase receptor 1). Previously, administration of exogenous VEGF-A, bound to a carrier protein called ELP (elastin-like polypeptide), significantly reduced free sFlt-1 levels and attenuated the hypertensive response in a rodent model of preeclampsia. However, VEGF-A administration induces multifactorial effects mediated through its direct activation of the Flk-1 receptor. In response to this, we developed a therapeutic chimera using ELP bound to VEGF-B, a VEGF isoform that binds to sFlt-1 but not to Flk-1. The purpose of this study was to evaluate the in vitro activity and pharmacological properties of ELP-VEGF-B and to test its efficacy in the reduced uterine perfusion pressure rat model of placental ischemia. ELP-VEGF-B was less potent than ELP-VEGF-A in stimulation of endothelial cell proliferation and matrix invasion, indicating that it is a weaker angiogenic driver. However, after repeated subcutaneous administration in pregnant rats, ELP-VEGF-B was maternally sequestered and reduced blood pressure when compared with saline treated animals following induction of placental ischemia (123.38±11.4 versus 139.98±10.56 mm Hg, P =0.0129). Blood pressure reduction was associated with a restoration of the angiogenic capacity of plasma from rats treated with ELP-VEGF-B. ELP-VEGF-B is a nonangiogenic, maternally sequestered protein with potential efficacy for treatment of preeclampsia.

Impact of hyperleptinemia during placental ischemia-induced hypertension in pregnant rats

2021 ◽  
Author(s):  
Ana C. Palei ◽  
Hunter L. Martin ◽  
Barbara A. Wilson ◽  
Christopher D. Anderson ◽  
Joey P. Granger ◽  
...  
Keyword(s):  
Cyclic Guanosine Monophosphate ◽  
Guanosine Monophosphate ◽  
Sprague Dawley ◽  
Pregnant Rats ◽  
No Donor ◽  
Induced Hypertension ◽  
Cgmp Signaling ◽  
Uterine Perfusion ◽  
Plasma Leptin ◽  
Placental Ischemia

The prevalence of preeclampsia and obesity have increased. While obesity is a major risk factor for preeclampsia, the mechanisms linking these morbidities are poorly understood. Circulating leptin levels increase in proportion to fat mass. Infusion of this adipokine elicits hypertension in non-pregnant rats, but less is known about how hyperleptinemia impacts blood pressure during placental ischemia, an initiating event in the pathophysiology of hypertension in preeclampsia. We tested the hypothesis that hyperleptinemia during reduced uterine perfusion pressure (RUPP) exaggerates placental ischemia-induced hypertension. On gestational day (GD) 14, Sprague-Dawley rats were implanted with osmotic mini-pumps delivering recombinant rat leptin (1 mg/kg per min, i.v.) or vehicle concurrently with the RUPP procedure to induce placental ischemia or Sham. On GD 19, plasma leptin was elevated in Sham+Leptin and RUPP+Leptin. Leptin infusion did not significantly impact mean arterial pressure (MAP) in Sham. MAP was increased in RUPP+Vehicle vs. Sham+Vehicle. In contrast to our hypothesis, placental ischemia-induced hypertension was attenuated by leptin infusion. To examine potential mechanisms for attenuation of RUPP-induced hypertension during hyperleptinemia, endothelial-dependent vasorelaxation to acetylcholine was similar between Sham and RUPP; however, endothelial-independent vasorelaxation to the nitric oxide (NO)-donor, sodium nitroprusside, was increased in Sham and RUPP. These findings suggest that NO/cyclic guanosine monophosphate (cGMP) signaling was increased in the presence of hyperleptinemia. Plasma cGMP was elevated in Sham and RUPP hyperleptinemic groups compared to vehicle groups but plasma and vascular NO metabolites were reduced. These data suggest that hyperleptinemia during placental ischemia attenuates hypertension by compensatory increases in NO/cGMP signaling.

Abstract P320: Proliferationof Endogenous T-regs Improves the Pathophysiology Associated with Placental Ischemia of Pregnancy

Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Tarek Ibrahim ◽  
Lukasz Przybyl ◽  
Ashlyn C Harmon ◽  
Denise C Connelius ◽  
Mark W Cunningham ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Inflammatory Cytokines ◽  
Perfusion Pressure ◽  
Treg Cells ◽  
Proinflammatory Response ◽  
Regulatory Interactions ◽  
Uterine Perfusion ◽  
Placental Ischemia ◽  
Pro Inflammatory Cytokines ◽  
New Onset

Preeclampsia (PE), new onset hypertension during pregnancy, is associated with pro-inflammatory cytokines and decreased regulatory immune mechanisms such as Tregs, IL-10 and IL-4. We believe this decrease in immune regulatory mechanisms leads to an uncontrolled proinflammatory response which contributes to most of the pathophysiology associated with PE. The Reduced Uterine Perfusion Pressure, RUPP, rat model of induced placental ischemia exhibits similar characteristics as women with PE including high blood pressure, elevated pro-inflammatory cytokines and cells and decreased Tregs, IL-4 and IL-10. Therefore, we hypothesized that stimulating Tregs by administration of a superagonist (SA) would increase the Treg profile in the RUPP rats which could reduce pro-inflammatory cytokines and blood pressure. The RUPP procedure was performed at gestation day 14 (GD14); SA was administered intraperitoneally at GD15, GD18 carotid catheters inserted, and GD19 MAP and pup weight, serum and tissues were collected. MAP in NP rats was 98.6 mmHg ± 4.71, 122.2 mmHg ± 1.84 in RUPPs which was improved to 110.789mmHg ± 1.23 in RUPP+SA. Circulating FoxP3+ Treg cells were 5.987% ± 1.69% of total T-cells population in NP, 0.77% ± 0.49% in RUPP rats but increased to 11.218% ± 2.9% in RUPP+SA; Circulating IL-6 levels were 41.008 ± 4.79 pg/mL in NP, 108.26 ± 25.99 pg/mL in RUPP, and 40.37 ± 4.49 pg/mL in RUPP+SA, Administration of the SA to the NP rats did not affect IL-6 Levels in comparison to NP at 36.79 ± 3.9 pg/mL. Plasma IL-10 Levels were at 58.399 ± 9.527 pg/mL in NP rats, these levels were significantly decreased in the RUPP rats, 26.298 ± 4.33 pg/mL, and treatment of the RUPPs with the SA significantly increased plasma IL-10 levels to 51.5486 ± 3.329 pg/mL. When the SA was given to NP rats, the levels for IL-10 were significantly higher compared to any of the other groups at 85.5207 ± 9.067 pg/mL. Placental Pre-pro Endothelin-1 (PPET-1) was increased 44.42 ± 0.269 fold in RUPP compared to NP 1 ± 0.255, but was decreased to 18.78 ± 0.48 in RUPP+SA. These data suggest an important role for up-regulating Treg cells to enhance the immune regulatory interactions and lower the hypertension without causing further reduction in fetal weight in response to placental ischemia during pregnancy.

scholarly journals Blockade of CD40 ligand for intercellular communication reduces hypertension, placental oxidative stress, and AT1-AA in response to adoptive transfer of CD4+ T lymphocytes from RUPP rats

2015 ◽  
Vol 309 (10) ◽  
pp. R1243-R1250 ◽  
Author(s):  
Denise C. Cornelius ◽  
Javier Castillo ◽  
Justin Porter ◽  
Lorena M. Amaral ◽  
Nathan Campbell ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Blood Pressure ◽  
T Cells ◽  
T Lymphocytes ◽  
Adoptive Transfer ◽  
Cell Communication ◽  
Cd40 Ligand ◽  
Type I ◽  
Uterine Perfusion ◽  
Placental Ischemia

Preeclampsia (PE) is associated with altered immune activation during pregnancy. We have previously shown that adoptive transfer of CD4+ T cells from the reduced uterine perfusion pressure (RUPP) rat model of PE increases blood pressure, oxidative stress (ROS), and inflammation in normal pregnant recipient rats. The objective of this study was to determine if blockade of communication via the CD40-CD40 ligand (CD40L) interaction between placental ischemia-induced CD4+ T cells with endogenous normal pregnant (NP) cells would improve pathophysiology that was previously observed in NP recipient rats of RUPP CD4+ T cells. Splenic CD4+ T lymphocytes were magnetically separated, incubated with 2.5 μg/ml anti-CD40 ligand (αCD40L) overnight, and transferred into NP rats on day 12 of gestation (NP+RUPP CD4+ T+anti-CD40L). On day 19 of gestation, blood pressure (MAP), blood, and tissues were collected. MAP was 99 ± 2 in NP ( n = 13), 116 ± 4 in NP+RUPP CD4+ T cells ( n = 7; P < 0.01); MAP only increased to 104 ± 2 in NP+RUPP CD4+ T cells+CD40L ( n = 24) ( P < 0.05 vs. NP+RUPP CD4+ T cells). Mechanisms of hypertension in response to RUPP CD4+ T cells include endothelin-1 (ET-1), ROS, and angiotensin II type I receptor (AT1-AA) were analyzed. Inhibition of CD40L binding reduced placental ET-1 to 2.3-fold above NP rats and normalized placental ROS from 318.6 ± 89 in NP+RUPP CD4+ T cells ( P < 0.05) to 118.7 ± 24 in NP+RUPP CD4+ T+anti-CD40L ( P < 0.05). AT1-AA was also normalized with inhibition of CD40L. These data suggest that placental ischemia-induced T-cell communication via the CD40L is one important mechanism leading to much of the pathophysiology of PE.

Abstract 211: Inhibition of Heme Oxygenase-1 (HO-1) Induces Mild Hypertension in Pregnant Rats

Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Eric M George ◽  
Frank Spradley ◽  
Joey P Granger
Keyword(s):  
Oxidative Stress ◽  
Blood Pressure ◽  
Nadph Oxidase ◽  
Oxidase Activity ◽  
Late Gestation ◽  
Heme Oxygenase 1 ◽  
Maternal Circulation ◽  
Pregnant Rats ◽  
Nadph Oxidase Activity ◽  
Significant Difference

In the preeclamptic patient, inadequate remodeling of the maternal vasculature exacerbates this effect, causing dramatically increased oxidative stress in the placenta, which has been shown to be an important component of the maternal hypertension. There is also increasing awareness that HO-1 may act as an important regulator of placental function during normal pregnancy and decreases in HO-1 activity have been implicated in the pathogenesis of preeclampsia. While previous work in pregnant mice demonstrated that pharmacological inhibition of HO-1 leads to elevations in blood pressure, the mechanisms involved in the hypertension are unclear. The purpose of this study was to test the hypothesis that HO inhibition in late gestation leads to increases in maternal blood pressure by altering angiogenic balance and increasing placental oxidative stress in pregnant rats. HO activity was inhibited with tin mesoporphyrin (SnMP) was administered on gestational day 14, and blood pressure was measured on gestational day 19 by indwelling carotid catheter before sacrifice. In response to SnMP treatment, maternal MAP was significantly increased (99±1 vs 113±2 mmHg, p<0.05, n=15 per group). Placental sFlt-1 (631±47 vs 648±26 pg/mg, p=0.76) levels in the placenta were not affected by HO inhibition. Additionally, there was no significant difference in free VEGF in the maternal circulation (287±22 vs 329±14 pg/ml, p=0.11). There was, however, a significant increase in placental NADPH oxidase activity in SnMP treated rats (2021±238 vs 3005±301 RLU/min/mg, p<0.05) as determined by NADPH dependent lucigenin luminescence. This is likely due to decreased production of bilirubin, which is known to inhibit NADPH oxidase activity, and suggests an important role for HO-1 as an antioxidant in the developing placenta.

Abstract 037: A Role for IL-17 to Activate Cytolytic Natural Killer Cells in Response to Placental Ischemia

Hypertension ◽  
2015 ◽  
Vol 66 (suppl_1) ◽  
Author(s):  
Denise C Cornelius ◽  
D'Andrea S Thomas ◽  
Jamil Elfarra ◽  
Taia R McAfee ◽  
Babbette LaMarca
Keyword(s):  
Blood Pressure ◽  
Nk Cells ◽  
Renal Dysfunction ◽  
Natural Killer ◽  
Cell Activation ◽  
Nk Cell ◽  
Blood Pressure Response ◽  
Cell Phenotype ◽  
Uterine Perfusion ◽  
Placental Ischemia

Women with preeclampsia (PE), newly developed hypertension and renal dysfunction during pregnancy, have small-for-gestational-age babies and demonstrate an increase in the inflammatory cytokine IL-17, placental oxidative stress, and cytolytic natural killer (NK) cell activation. The stimulus of the cytolytic NK cell phenotype during PE is currently unknown. Moreover, the specific role of cytolytic NK cells in the pathophysiology of preeclampsia has not been clearly defined. The reduced uterine perfusion pressure (RUPP) model of placental ischemia exhibits many of the characteristics of preeclampsia including hypertension, renal dysfunction, chronic inflammation and intrauterine growth restriction (IUGR). In this study, we tested the hypothesis that placental ischemia results in cytolytic activation of NK cells, and examined a role for the increased IL-17, in response to placental ischemia, to activate cytolytic NK cells. In this study, blood pressure (MAP) and pup weight were measured, and PBMCs and placental lymphocytes were examined via flow cytometry for surface makers of cytolytic NK cell activation. MAP significantly increased in response to placental ischemia from 103±4.1 mmHg in NP (n=6) to 129.1±3.1 mmHg (n=8) in RUPP rats (p<0.001). Neutralization of IL-17 with a soluble receptor attenuated the blood pressure response to 106.3±2.3 mmHg in RUPP+IL-17RC rats (n=3). Pup weight is significantly decreased in RUPP rats (2.52±0.18g in NP vs 2.03±0.05g in RUPP (p<0.05)), which increased to 2.54±0.36g in RUPP+IL-17RC. Cytolytic activation of circulating NK cells was not significantly changed among any of the groups (NP: 2.49±1.1%; RUPP: 7.74±3.2%; RUPP+IL-17RC:5.50±2.8%). However, cytolytic activation of placental NK cells increased in response to placental ischemia (NP: 3.4±1.1% vs RUPP 10.0±3.4%), and was completely attenuated after treatment with the soluble IL-17 receptor (RUPP+IL-17RC: 0.33±0.17%). These results suggest a role for placental ischemia and increased IL-17 to stimulate cytolytic NK cells. Furthermore, this study links the IL-17 pathway with cytolytic NK cell activation and IUGR in response to placental ischemia, potentially identifying new therapeutic targets to improve maternal and fetal outcomes of PE.

Abstract 273: Increased Blood Pressure and Proteinuria and Absence of Increased Nitric Oxide (NO) Production During Pregnancy in the Dahl Salt Sensitive (S) Rat

Hypertension ◽  
2013 ◽  
Vol 62 (suppl_1) ◽  
Author(s):  
Ellen E Gillis ◽  
Jennifer N Mooney ◽  
Jan M Williams ◽  
Michael R Garrett ◽  
Jennifer M Sasser
Keyword(s):  
Blood Pressure ◽  
Genetic Model ◽  
Late Pregnancy ◽  
Normal Pregnancy ◽  
Kidney Cortex ◽  
No Production ◽  
Pregnant Rats ◽  
Telemetry Unit ◽  
Nos Inhibitor ◽  
Volume Retention

In normal pregnancy, systemic vasodilation due to increased NO production allows a drop in blood pressure (BP) despite increased volume retention. Little is known about the pathogenesis of preeclampsia, defined by increased BP and proteinuria, due to a lack of animal models that spontaneously develop the disease. Here we tested the hypothesis that the Dahl S rat, a genetic model of hypertension and kidney disease, is also a spontaneous model of preeclampsia. Female Dahl S rats were implanted with a telemetry unit, and baseline BP was recorded. Rats were placed in metabolic cages for 24 hr urine collection while on a low nitrate diet, and urinary protein and NO metabolite concentrations were measured via Bradford and Greiss assays, respectively. There were no differences in baseline BP (152±1 vs 151±4 mmHg) or proteinuria (61±10 vs 60±17 mg/d) in the rats selected for mating vs virgin rats (n=5-7). Pregnancy was confirmed by presence of sperm (day 1). Measurements were made during mid and late pregnancy (days 10-11, 17-18), and terminal measurements were taken on day 19. Pregnant rats exhibited an increase in BP and proteinuria with no change in urinary NOx excretion (Table), while no changes were observed in age-matched virgin rats. Kidney cortex abundance of neither NOS1 nor NOS3 was increased at late pregnancy; however, plasma concentration of the endogenous NOS inhibitor ADMA was increased in late pregnant compared to virgin rats (0.82±0.06 vs. 0.62±0.06 μM, p<0.05). These data suggest that the Dahl S rat cannot upregulate NO production during pregnancy; therefore, this relative NO deficiency may contribute to worsening hypertension and proteinuria during pregnancy in this strain.

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