bluuebunny/crossref_metadata_2025 huggingface dataset:
Inducible Regulation of the Human Brain Natriuretic Peptide Promoter in Transgenic Mice
Authors: He Quan , Yang Xiao-Ping
Published: March 2022

P187

Brain natriuretic peptide (BNP), a cardiac hormone, is rapidly elevated in the infarcted heart, and plasma BNP levels reflect the degree of left ventricular dysfunction. Our previous work indicated that the proximal promoter of the hBNP gene was active when injected into adult rat hearts. To study tissue-specific and inducible regulation of the hBNP gene in vivo, we generated transgenic mice containing the hBNP promoter (-408 to +100) coupled to a luciferase reporter gene. Cardiac function was measured by 2D echocardiography and transgene expression was measured by luciferase assay and tissue section immunostaining. Luciferase activity was measured in the heart, brain, kidney, liver, lung and skeletal muscle of 4 lines of mice. High levels of luciferase activity were only detected in the heart, with ventricular expression higher than atrial expression (LV=RV>RA>>LA). Immunostaining with a luciferase antibody showed staining in myocytes (line 203). There were no differences in the blood pressure, heart rate, heart size and function of transgenic mice compared with controls (line 203). To test whether the transgene responded to a pathophysiological stimulus, mice had coronary artery ligation to produce infarction. Luciferase activity was measured after 48 hr and 1, 3 and 4 weeks. Luciferase activity driven by the hBNP promoter was 4 to 41-fold higher in the infarcted left ventricle vs sham-operated animals (lines 203, 83 and 86) at 48hr, 3.1-fold higher at 1 week (line 203), and 2.5-fold at 3 and 4 weeks (line 203). There was a clear increase in heart weight to body weight ratio and a decrease in cardiac output and ejection fraction 4 weeks post-infarction. Endogenous BNP mRNA was increased in infarcted hearts from a separate group of non-transgenic mice at 48 hr. We concluded that: 1) the hBNP promoter is preferentially expressed in the heart; 2) 408hBNPLuc transgenic mice have normal blood pressure and cardiac function; and 3) the hBNP promoter is stimulated by ischemic injury following infarction, as is the endogenous mouse BNP gene. These data suggest that we have a valid model for the study of both basal and inducible regulation of the hBNP gene in vivo.
Alterations of Central Vasopressinergic System in Transgenic Rats with Low Brain Angiotensinogen
Authors: Baltatu Ovidiu , Couto Aurea S , Santos Robson A S , Ganten Detlev , Campagnole-Santos Maria J , Bader Michael
Published: March 2022

P188

The consequence of a permanent alteration of the brain renin-angiotensin system (RAS) on central vasopressinergic system was studied at the level of the nucleus tractus solitarii (NTS) of transgenic rats with a deficit in brain angiotensinogen, TGR(ASrAOGEN). Vasopressin (AVP) (100 pmol/ 50nl) or desmopressin (DDAVP, V2 receptor agonist) (100pmol/ 50nl) were microinjected into the NTS of urethane-anesthetized TGR(ASrAOGEN) and Sprague-Dawley (SD) rats. Blood pressure and heart rate were measured via a femoral artery catheter and the baroreflex induced by phenylephrine (baroreflex bradycardia) evaluated. Hypothalamic levels of AVP mRNA were measured by ribonuclease protection assay (RPA). AVP microinjections induced a greater decrease of the MAP in TGR(ASrAOGEN) in comparison with SD rats (-19.9 ± 5.2 vs. -7.5 ± 0.7 mmHg, p<0.05). The significantly higher baroreflex sensitivity observed in TGR compared to that of SD rats was normalized after AVP microinjection (0.76 ± 0.1 vs. 0.3 ± 0.1 ms/ mmHg, before and after AVP microinjection in TGR rats, p<0.05). The microinjections of DDAVP in the NTS produced also a decrease of MAP, which was significantly higher in TGR(ASrAOGEN) in comparison with the control strain (-21.2 ± 0.9 vs. -10 ± 1.2 mmHg, p<0.05). Hypothalamic AVP mRNA levels were not significantly altered in TGR rats. These results demonstrate that a permanent deficit in the brain angiotensinogen synthesis can alter the functionality of central vasopressinergic system. However, the hypothalamic AVP synthesis is not altered. The increased sensitivity to AVP and DDAVP in TGR(ASrAOGEN) rats indicates a functional upregulation of AVP receptors in the NTS and further evidences the interaction between RAS and the vasopressinergic system within the brain. Furthermore, this study for the first time shows the existence of functional DDAVP-sensitive vasopressin receptors at the NTS level.
Adrenomedullin and Vasculitis, Study with Knock Out Mouse
Authors: Shimosawa Tatsuo , Shibagaki Yugo , Kangawa Kenji , Kato Shigeaki , Kawai Junsuke , Yamasaki Masao
Published: March 2022

P190

Objectives Adrenomedullin(AM) is not only a potent vasodilator but also regulates several hormone release such as aldosterone, NO and also regulates inflammatory reactions. In order to clarify its physiological role, we generated AM knock-out mouse and investigated its cardiac and vascular changes. Method A point mutation to stop AM translation were induced and by conventional method, AM knock-out mouse was generated. As homozygote was lethal we used heterozygote for this study. In heterozygote plasma and tissue AM level were as half as wild type. Angiotensin II were continuously administered and 8% NaCl diet were loaded to 8 weeks old male heterozygote and wild type for 2 weeks. In some mice, we wrapped silicone tube around the femoral artery and transferred adrenomedullin gene via adenovirus vector topically. Blood pressure were monitored by tail cuff method. After 2 weeks, heart weight were measured and pathological changes were observed. Results Baseline SBP were comparable between heterozygote and wild type (150±10 mmHg vs 142±8 mmHg). One week after angiotensin II and salt loading both mice increased blood pressure to 170±9 mmHg in heterozygote and 168±10 mmHg in wild type. At the end of the study SBP of heterozygote were 160±13 mmHg and that of wild type were 173±9 mmHg. Heart weight/BW were significantly larger in heterozygote (0.0068±0.0003) than in wild (0.0061±0.0002). Perivascular area of coronary artery from heterozygote was full of inflammatory cells and fibrosis. In severe case, coronary aretery showed fibrinoid necrosis. These findings were not found in kidney or other arterioles.The femoral artery from heterozygote showed marked medial proliferation and stenosis compared to wild type. And this change was rescued by AM administration. Conclusion AM is protective against coronary artery injury and cardiomegaly.
Adenovirus-Mediated Human Kallikrein Gene Delivery Increases Endogenous Rat Tissue Kallikrein in Hypertensive Rat Models
Authors: Wang Cindy , Montanari David , Chao Lee , Chao Julie
Published: March 2022

P201

Our recent studies showed that adenovirus-mediated human tissue kallikrein gene delivery attenuated hypertension, cardiac hypertrophy, and renal injury in various hypertensive rat models. However, mechanisms underlying the beneficial effects of human kallikrein gene delivery are not clear. In the present study, we investigated the potential of human kallikrein gene delivery on synthesis and excretion of endogenous rat tissue kallikrein in normotensive and hypertensive rat models. Adenovirus carrying the human kallikrein cDNA under the control of cytomegalovirus (CMV) promoter/enhancer was administered via tail vein injection. Control rats received adenovirus harboring the b-galactosidase or luciferase gene under control of the CMV promoter/enhancer. A single injection of the human tissue kallikrein gene caused a prolonged blood pressure-lowering effect in spontaneously hypertensive rats, two kidney-one clip, Dahl salt-sensitive, deoxycorticosterone acetate-salt and monocrotaline-induced pulmonary hypertensive rats, while systolic blood pressure of normotensive Sprague-Dawley rats remained unaltered. Human kallikrein gene delivery significantly increased endogenous rat tissue kallikrein levels in the kidney and urine of different models of hypertensive rats as compared with their respective controls. However, urinary excretion of rat tissue kallikrein was not affected by human kallikrein gene delivery in normotensive rats. The endogenous rat tissue kallikrein mRNA expression in the kidney remained unaltered after human kallikrein gene delivery, which indicated that expression of human kallikrein in hypertensive rats increased endogenous rat kallikrein synthesis and excretion. These findings indicate that beneficial effects of human kallikrein gene delivery in hypertensive rat models are mediated, at least in part, by enhanced endogenous tissue kallikrein-kinin system.
Central Antisense Treatment Against Thyroliberin Normalizes Blood Pressure in Spontaneously Hypertensive Rats Without Affecting Thyroid Status.
Authors: Garcia Silvia I , Alvarez Azucena L , Porto Patricia I , Hockl Pablo F , Garfunkel Victoria M , Finkielman Samuel , Pirola Carlos J
Published: March 2022

P202

Thyroliberin (TRH) participates in central cardiovascular regulation and hypothalamic TRH precursor gene overexpression induces hypertension which can be reversed by antisense (AS) treatment. SHR show an increased central TRH synthesis and release and TRH receptor number. We show here that a phosphotioate AS against the preTRH injected icv decreased the augmented diencephalic TRH content (ng/mg protein) along with a normalization of systolic blood pressure (SABP) at 24-48 hs in SHR without effect in normotensive WKY rats (table). Saline or sense treatment had no effects. To investigate if changes in thyroid function may explain these results, we studied plasma TSH, T
3
(ng/ml) and T
4
(ug%) in control (CON) and AS-treated WKY and SHR. Although TSH was elevated in SHR compared to WKY rats in basal conditions and AS reverted it (table), no differences (n=5) were observed between strains with or without AS treatment in plasma T
4
(CON; WKY: 5.0±0.4 vs SHR: 5.3±0.5 and AS; WKY:5.4±0.3 vs SHR: 5.6±0.4) or T
3
(CON; WKY: 1.3±0.4 vs SHR: 1.1±0.2 and AS; WKY: 1.5±0.2 vs SHR: 1.4±0.3). To summarize, TRH AS decreases the higher diencephalic TRH content and changed arterial blood pressure to that of WKY rats even though SHR were basally and after AS treatment remained clinically euthyroid. These results suggest that the central TRH system is involved in the etiopathogenesis of hypertension in this model.
Abstract 102: Aldosterone Evokes Senescence-associated Secreting Phenotype And Subsequent Apoptosis In Proximal Tubular Cells
Authors: Kitada Kento , Nakano Daisuke , Hitomi Hirofumi , Yatabe Junichi , Felder Robin A , Kobori Hiroyuki , Nishiyama Akira
Published: March 2022

We previously reported that aldosterone/mineralocorticoid receptor activation caused cell senescence via p21, a cell cycle regulator, -dependent pathway in proximal tubules of rat kidney and human proximal tubular cells. However, functional influences of cell senescent on the kidney are still unclear. In the present study, we hypothesized that aldosterone-induced cell senescence caused cell apoptosis by increasing the secretion of apoptotic factors (n=6 in all groups). Aldosterone increased senescent cells at day 3 and day 5 in human proximal tubular cells, and the changes were accompanied by the increase in p21 protein expression (day 3: 2.9±0.7 fold, day 5: 6.5±0.9 fold, p<0.05) and TNF-α mRNA (day 3: 2.3±0.3 fold, day 5: 2.4±0.6 fold, p<0.05). In addition, aldosterone also increased secretion of TNF-α into the culture medium compared with vehicle-treated group (day 3: 15.7±1.2 vs 7.2±1.6 pg/ml; day 5: 33.3±5.7 vs 11.8±2.3 pg/ml; p<0.05, respectively): gene silencing of p21 abolished these changes. Meanwhile, 3-day treatment with aldosterone showed no sign of cell apoptosis, which was evaluated by terminal nick end labeling (TUNEL) and annexin V/propidium iodide (PI) staining, and 5-day treatment with aldosterone increased cell apoptosis (TUNEL: aldosterone, 6.4±1.5%; vehicle, 0.6±0.3%; annexin V/PI: aldosterone, 5.8±0.8%; vehicle, 0.8±0.3%; p<0.05). Importantly, p21 siRNA and TNF-α neutralizing antibody abolished these aldosterone-induced apoptotic changes (TUNEL: 1.4±0.1 and 0.9±0.5%; annexin V/PI: 0.9±0.3 and 1.5±0.9%; respectively). These results indicate that aldosterone increases TNF-α synthesis and secretion in proximal tubular cells via p21/senescence-dependent pathway, and that the secreted TNF-α plays an important role as an autocrine/paracrine factor to mediate cell apoptosis, which may be involved in aldosterone-induced renal damage.
Abstract 104: Angiotensin Converting Enzyme 2 Regulates Endothelial Progenitor Cell Function Through the eNOS and NAPDH Oxidase Pathways
Authors: Chen Ji , Xiao Xiang , Chen Shuzhen , Zhang Cheng , Shenoy Vinayak , Raizada Mohan K , Zhao Bin , Chen Yanfang
Published: March 2022

Angiotensin converting enzyme 2 (ACE2) is a key vasoprotective member of the renin-angiotensin system that catalyzes angiotensin II (Ang II) into Ang (1-7). We have shown endothelial progenitor cells (EPCs) from the hypertensive human renin and angiotensinogen transgenic (R+A+) mice are dysfunctional. Here, we studied the role of ACE2 in EPC function. Bone marrow derived-EPCs were cultured from R+A+ mice and its controls(R-A-). EPCs (1×10
5
cells/well) were transduced with 5×10
6
infectious units of lentivirus-ACE2 (Lenti-ACE2) or Lenti-GFP. The levels of ACE2, endothelial nitric oxide synthase (eNOS) and NADPH oxidase subunits (Nox2, 4) were measured by Western blot. EPC functions (migration and tube formation) were evaluated using the Boyden chamber method and an assay kit. For blocking experiments, ACE2 inhibitor (DX600) or eNOS inhibitor (L-NAME) was added in culture medium. Reactive oxygen species (ROS) and nitric oxide (NO) production in EPCs was determined by dihydroethidium staining and 4, 5-diaminofluorescein method. We observed that 1) eNOS expression and NO production were lower, whereas Nox2, 4 expression and ROS production were higher in the EPCs from R+A+ mice. 2) Lenti-ACE2 transduction resulted in an 8-fold increase in ACE2 expression in EPCs. This was associated with an increases in eNOS expression and NO production, while decreases in Nox2, 4 expression and ROS production. 3) ACE2 over-expression enhanced migration and tube formation function of EPCs from R+A+ mice. 4) The effects of ACE2 over-expression on EPCs were able to be partially inhibited by DX600 or L-NAME. In conclusion, our data demonstrate that ACE2 improves EPC function via eNOS and Nox pathways.
Abstract 11: Characterizing Gender-Specific Differences in Angiogenesis and Protection from Hypertension: Congenic Lines Lead to Identification of Btg2 as a Candidate Gene
Authors: Stodola Timothy , Xiao Bing , Hoffman Matthew , Flister Michael , Moreno Carol , Greene Andrew
Published: March 2022

Whole and partial chromosome introgression from the Brown Norway (BN) rat into the Dahl Salt Sensitive (SS) rat is a valuable tool for identifying genes and pathways associated with disease phenotypes in the SS rat. We have created two congenic lines with BN substitutions differing by 22.9 Kbp. The congenic regions differ by one gene,
Btg2
, and have 35 sequence variants, three of which occur in
Btg2
. We have characterized angiogenesis and development of hypertension in these new strains, and since
Btg2
is known to be modulated by estradiol, we measured both phenotypes in males and females. Mean arterial pressure (MAP) was measured by telemetry after three weeks of 8% NaCl diet. Angiogenesis was measured by electrical stimulation of one hindlimb (Tibialis anterior, TA, and Extensor digitorum longus, EDL) with the contralateral leg acting as control. Renal damage was assessed by 24-h protein/albumin excretion after two weeks on 8% NaCl diet.
Btg2
expression was determined by QRT-PCR on renal cortex and medulla as well as stimulated and unstimulated TA muscle. Males from both lines had the same MAP following three weeks of 8% NaCl diet (Btg2
BN
: 187±5 mmHg, Btg2
SS
: 185±3). Females with Btg2
BN
had significantly higher MAP (180±6 mmHg) than Btg2
SS
females (153±7 mmHg). Angiogenesis in response to electrical stimulation was observed in Btg2
BN
males (TA=20.0±4.5% increase in vessel density, EDL=15.8±5.8%), but not in Btg2
SS
males (TA= 5.1±2.2%, EDL=4.4±2.7%). Females of both strains had angiogenesis (Btg2
BN
: TA=9.8±6%, EDL=8.5±1.2%; Btg2
SS
: TA=12.7±2.4%, EDL=12.1±4.1%). Btg2
BN
females had significantly higher protein excretion than SS and Btg2
SS
was significantly lower; males had no significant differences.
Btg2
mRNA expression in male skeletal muscle displayed a 2-fold increase (stimulated to unstimulated) in Btg2
BN
and a 3.5-fold increase in Btg2
SS
. Males had no differences in expression in renal cortex or medulla, but females had significant differences in cortex (Btg2
BN
: 1.8±0.2 fold change, Btg2
SS
: 0.4±.01). These data suggest
Btg2
expression may contribute to the development of hypertension and inhibited angiogenic response in SS rats, with gender-specific differences in the expression of this gene.
Abstract 111: Elevated Sympathetic Drive to the Bone Marrow Contributes to the Inflammatory Response and Dysfunctional Endothelial Progenitor Cells in the Spontaneously Hypertensive Rat
Authors: Zubcevic Jasenka , Shan Zhiying , Li Wencheng , Feng Yumei , Raizada Mohan K
Published: March 2022

Introduction:
Bone marrow (BM)-derived endothelial progenitor cells (EPCs) contribute to the repair of vasculature, whereas the inflammatory cells (ICs) contribute to the vascular damage. Thus, imbalanced EPC/IC ratio, coupled with dysfunctional EPCs, are key in the vascular pathophysiology of hypertension. We demonstrated that SHR, which have elevated sympathetic drive, exhibit a significantly lower BM EPC/IC ratio due to lower EPCs and higher ICs. The inverse relationship between the sympathetic drive and EPC/IC ratio is supported by our data showing that elevation in the overall sympathetic drive in the WKY, as a result of the light:dark cycle, decreases the EPC/IC ratio. This has led us to propose that the SHR exhibit chronically elevated sympathetic drive to the BM, which contributes to the impaired EPC/IC ratio and EPC dysfunction.

Methods:
Femur from 21-week old SHRs (MAP=∼145 mmHg) and WKYs (MAP=∼100 mmHg) were used to determine norepinephrine (NE) and tyrosine hydroxylase (TH) levels. Femur BMs were flushed, and cell supernatants collected for NE measurements (ELISA). Femurs from a separate group of rats were fixed and used for TH quantification (IHC). Additional WKY and SHR were used for BM injection of GFP-tagged pseudorabies virus (GFP-PRV) to compare the extent of retrograde labeling from the femur BM to the brain autonomic areas (SFO, PVN, RVLM, NTS).

Results:
We observed a ∼80% higher NE levels, and a ∼2.1 fold higher TH density, in the BM of SHR compared to WKY. This was accompanied by a ∼52% decrease in EPC/IC ratio and a ∼44% decrease in EPC function in the SHR compared to the WKY. Additional evidence for the increased sympathetic communication between the SHR autonomic brain areas and the BM was provided by PRV-GFP retrotracing. The data showed a profound labeling of the PVN neurons in the SHR compared to WKY, 7 days post-PRV-GFP injection. Less significant labeling was observed in other autonomic areas (RVLM>NTS>SFO) under similar conditions.

Conclusion:
These observations demonstrate, for the first time, that there is an elevated sympathetic drive to the BM in the SHR. This is associated with an impaired BM activity, reflecting a decrease in EPCs and increase in ICs, which may contribute to the vascular pathophysiology in neurogenic hypertension.
Abstract 112: Organum Vasculosum Lateral Terminalis (OVLT) Contributes to Na+-Induced Sympathoexcitation and Hypertension
Authors: Wolfgang Lawrence L , Stocker Sean D
Published: March 2022

High dietary salt intake increases plasma and CSF Na+ concentration to elevate sympathetic nerve activity (SNA) and arterial blood pressure (ABP). Ablation of the anterior ventral 3
rd
ventricle (AV3V) region attenuates the elevation in SNA and ABP during acute and chronic salt loading. The AV3V contains numerous hypothalamic nuclei including osmosensitive neurons of the OVLT. The purpose of this study was twofold: 1) to determine whether OVLT neurons mediate the sympathetic and hypertensive effects of central salt loading and 2) to characterize the changes in SNA to different vascular beds and/or end organs.

Male Sprague-Dawley rats received an intracerebroventricular (ICV) infusion of 1M NaCl (5ul over 10min) before and after lesion of AV3V (n≥4) or OVLT (n=7). ICV infusion of NaCl increased mean ABP (8.9±1.0mmHg) and lumbar SNA (26.4±3.6%) but decreased renal (-18.6±2.3%) and splanchnic SNA (-10.6±2.3%). Electrolytic lesion of the AV3V region attenuated this Na+-induced increase in ABP (8.9±1.0 vs 1.7±0.4mmHg, p=0.001) and lumbar SNA(26.4±3.6% vs 8.0±1.9%, p=0.001) but did not alter the inhibition of renal SNA (-18.6±2.3% vs -19.2±3.5%, p>0.8) and splanchnic SNA (-10.6.±2.3% vs -8.2±1.7%, p>0.4). ICV infusion of 1M NaCl produced similar increases in ABP, lumbar, renal and splanchnic SNA between control versus sham-lesion animals. Selective lesion of the OVLT attenuated the Na+-induced increase in ABP (10.4±2.0 vs 5.8±0.8mmHg, p<0.05) and lumbar SNA (31.8±3.7 vs 16.3±2.3% p<0.02). OVLT ablation also attenuated the inhibition of renal SNA (-18.2±2.6 vs -7.5±2.4%, p<0.02) and tended to lessen the inhibition of splanchnic SNA (-8.8±1.9 vs -4.0±1.1%, p=0.065). Even though both AV3V and OVLT lesions attenuated the increase in lumbar SNA and ABP in response to central Na+ load, the magnitude of the attenuation was significantly greater in AV3V versus OVLT-lesioned animals (p<0.05). Taken together, these findings suggest that acute increases in CSF Na+ activate OVLT neurons to selectively increase lumbar SNA and ABP. However, our findings also suggest that structures other than the OVLT participate in the sympathoexcitatory response to increased CSF Na+.
Abstract 114: Selective Activation of the Renin-Angiotensin System in the Subfornical Organ is Sufficient to Elicit Fluid and Sodium Intake Behaviors
Authors: Coble Jeffrey P , Cassell Martin D , Grobe Justin L , Sigmund Curt D
Published: March 2022

Increased activity of the renin-angiotensin system (RAS) within the brain results in polydipsia and hypertension, and various lines of evidence suggest that the subfornical organ (SFO) is an important region mediating these effects. We sought to verify a model of spatially- and temporally-inducible angiotensin (ANG) production, and to determine the sufficiency of ANG production within the SFO to elicit polydipsia and sodium intake. Mice expressing human renin via the neuron-specific promoter, synapsin (sR mice), were bred with mice expressing an inducible human angiotensinogen (hAGT) gene via the ubiquitous CAG promoter (A-Red mice) to generate sRA-Red mice. Exposure of the A-Red construct to Cre-recombinase results in excision of a dsRed reporter gene, and induction of hAGT expression. An adenovirus encoding Cre and GFP (AdCre) was injected into the lateral cerebral ventricle (ICV) of sRA-Red mice or control littermates (NT) to target the SFO. At baseline, fluid (NT: 0.18±0.03 vs sRA-Red: 0.19±0.04 mL/g/day) and sodium intakes (NT: 0.53±0.11 vs sRA-Red: 0.74±0.21 mEq/day) were similar between NT and sRA-Red mice. After 21 days sRA-Red mice receiving AdCre exhibited polydipsia (NT: 0.24±0.02 vs sRA-Red: 0.40±0.04 mL/g/day, P<0.05) and increased sodium intake (NT: 0.88±0.05 vs sRA-Red: 1.59±0.19 mEq/day, P<0.001). We validated SFO-specific targeting using a ROSA-TdTomato reporter mouse line. Cre-mediated recombination persisted in the SFO for at least 60 days after injection. Together, these data support the hypothesis that SFO-specific hyperactivity of the RAS is sufficient to cause polydipsia and sodium intake. We are currently investigating the effect on arterial pressure.
Abstract 12: Regulation of Hypertension by Sex specific T Cell Subtypes
Authors: Ji Hong , Zheng Wei , Liu Jun , Li Xiangjun , Wu Xie , Bajaj Bilkish , Sandberg Kathryn
Published: March 2022

Background:
Studies in humans and animal models of hypertension indicate arterial pressure is modulated by distinct T cell populations. Recombination activating gene-1 (Rag1)-deficient mice lack B and T cells and exhibit lower mean arterial pressure
(MAP)
than wild type mice during angiotensin II
(Ang II)
-induced hypertension. Adoptive transfer of splenic T cells from male wild type
(WT)
mice restores the Ang II-dependent hypertension in male Rag1 mice.

Objective:
This study investigated the impact of the sex of the T cell donor on T cell modulation of blood pressure during Ang II-induced hypertension in the male Rag1 mouse in order to gain insight into the mechanisms contributing to sex differences in hypertension.

Method:
Mature CD8
+
T cells were isolated using flow cytometry from male (

CD8
M

) and female (

CD8
F

) C57/Bl6 WT mice and injected into the jugular vein (8 x 10
6
T cells/mouse) of male Rag1 mice. Three weeks later, radiotransmitters were implanted and MAP was recorded before and after Ang II (490 ng/min/kg) was infused by osmotic minipump for two weeks. Once the experiment was terminated, T cell subpopulation frequencies in the spleen and kidney were assessed by fluorescence activated cell sorting, immunohistochemistry and real-time PCR.

Results:
Adoptive transfer of CD8
M
restored the magnitude of the Ang II-induced hypertension to WT levels in male Rag1 mice. In contrast, adoptive transfer of CD8
F
attenuated the hypertension [peak MAP (mm Hg): WT 143 ± 4.1; Rag1, 127 ± 2.8*; Rag1+CD8
M
, 142 ± 4.0; Rag1+CD8
F
, 120 ± 4.0*; n=10-12/group *p<0.01 vs WT]. There was a lower frequency of splenic FoxP3
+
CD4
+
T regulatory (
Treg
) cells in the male WT mouse spleen than in female spleens in the whole mature T cell population [Treg (%): Male, 3.2 ± 0.4 vs Female, 5.2 ± 0.3; p<0.01]. Furthermore, there was a lower frequency of splenic FoxP3
+
CD125
+
Treg cells in the CD4
+
population after adoptive transfer of CD8
M
compared to CD8
F
in male Rag 1 mice [Treg (%): Rag1+CD8
M
, 9.7 ± 1.4 vs CD8
F
, 14.7 ± 1.7; p<0.05].

Conclusions:
This study suggests sex differences in the Treg population contributes to why men have higher MAP than women up through the fifth decade of life.
Abstract 120: Central Prostaglandin D Synthase Inhibition Blocks Development of Chronic Angiotensin II-salt Hypertension in the Rat.
Authors: Asirvatham-Jeyaraj Ninitha , Fink Gregory D
Published: March 2022

Hypertension (HT) is still the major risk factor for various cardiovascular diseases. Previously we found that central cyclooxygenase-1 (COX-1) inhibition prevented the development of angiotensin II (AngII)-salt HT and sympathetic hyperactivity in Sprague Dawley rats. We found a significant up-regulation of prostaglandin D synthase (PGDS) mRNA levels in the organum vasculosum lamina terminalis, a circumventricular organ. This was accompanied by a significant increase in the protein levels of PGDS in the choroid plexus lining the ventricles. Therefore we hypothesized that the enzyme, PGDS is critical for the development of HT in this model. To test this hypothesis, adult male Sprague Dawley rats were implanted with radio-telemeters for hemodynamic measurements. After 3 days of basal recordings, rats on 2% NaCl diet were pretreated with vehicle or AT56, a PGDS inhibitor (10mg/kg, ICV) through a mini-osmotic pump. From day 8, all rats received AngII (150 ng/kg/min, s.c.). In vehicle-treated rats, mean arterial pressure (MAP) rose significantly. Rats that received AT56 showed attenuation of MAP compared to vehicle-treated rats (p<0.05). To examine if PGDS drives sympathetic nerve activity in this model, we treated these animals with the ganglionic blocker, hexamethonium (30mg/kg BW, i.p.) on day 14. In AT56-treated rats, fall in MAP was significantly lower than that of the control rats after ganglionic blockade. We conclude that PGDS products or the enzyme by itself is critical for the development of AngII-salt sympathoexcitation and HT.
Abstract 122: Global Longitudinal Peak Strain Detects Early Cardiac Damage in Hypertensive Children
Authors: Shamszad Pirouz , Knudson Jarrod D , Feagin Douglas K , Slesnick Timothy C , Feig Daniel I
Published: March 2022

Background:
Childhood hypertension is increasingly common and likely contributes to the premature development of cardiovascular and renal disease. Early detection of hypertensive cardiac damage may allow for prompt therapy and reduce the risk of late morbidity and mortality. While left ventricular mass index (LVMI) has been used as a surrogate of hypertensive cardiac damage in children, its prognostic and diagnostic value is not completely understood in this population.

Objective:
To test the hypothesis that strain assessment using automated function imaging (AFI) detects cardiac changes in hypertensive children earlier than standard 2D echocardiographic techniques.

METHODS:
A cross-sectional study of hypertensive children < 19 years old between October 2010 and May 2012 was performed. Any patient who was newly diagnosed with hypertension and underwent echocardiographic examination including standard 2D, Doppler, and automated function imaging (AFI) modalities was included. Global peak longitudinal systolic strain (GLPSS) was measured using a 17 segment model of the left ventricle. All echocardiographic measures were compared to normative reference values for age.

Results:
Twenty four patients (mean age 14.6 ± 2.7 years, 67% male) were identified. Mean systolic and diastolic blood pressure index was 1.1 ± 0.1 and 0.9 ± 0.1, respectively. Mean LVMI did not significantly differ from 95
th
-percentile normative values (41.6 ± 11.2 g/m
2.7
vs. 39.3 ± 1.5 g/m
2.7
,
p
= 0.328). Mean GLPSS was significantly lower than 5
th
-percentile normative values (-17.6 ± 2.5 vs. -19.5 ± 0.42,
p
= 0.001) and were decreased across all myocardial segments. Left atrial volume was significantly higher than reported normal values in children (27.6 ± 7.3 ml/m
2
vs. 22.0 ± 6.0 ml/m
2
,
p
= 0.002). No patient exhibited abnormal shortening or ejection fraction, mitral E-wave to A-wave ratio, or lateral mitral E-wave to e’-wave ratio.

Conclusions:
A population of unselected, newly diagnosed hypertensive adolescents had atypically low GLPSS and increased left atrial volume. The use of GLPSS measured by AFI may be a more sensitive marker of early myocardial remodeling in hypertensive children and routine measurement of GLPSS should be considered.
Abstract 123: An Assessment of the Effects of Nebivolol, Carvedilol and Irbesartan on Left Ventricular Hypertrophy Due to Hypertension
Authors: Degirmenci Husnu , Acikel Mahmut , Bakirci Eftal M , Duman Hakan , Tas Hakan , Simsek Ziya , Demirelli Selami , Aksakal Enbiya , Karakelleoglu Sule , Erol Mustafa K
Published: March 2022

The aim of this study is to research if the new generation beta-blockers (BB), carvedilol (C) and nebivolol (N), are as effective as irbesartan (I) on left ventricular hypertrophy (LVH) and to research whether or not there is a difference between C and N treatments.

Method:
This study is a clinical, prospective and cohort study. The study included 85 patients (mean age:56.6±9.6 years) with stages 1 or 2 hypertension and LVH who didn’t receive antihypertensive. Three different treatment groups [I (n=28), N (n=25) and C (n=32)] were assessed clinically and echocardiographically 3, 6 and 12 months after the initial treatment. Devereux formula was used in the measurement of left ventricular mass (LVM). LVM index (LVMI) ≥125 g/m
2
in male and ≥110g/m
2
in female was accepted as LVH.

Results:
There was no significant difference among treatment groups according to the initial LVMI and blood pressures (BP). Both between I and N groups and between I and C groups, there was a significant difference in the measurements of 12
th
month (p<0.05) while there wasn’t a significant difference in 3
rd
and 6
th
months according to LVMI. There was no significant difference between N and C groups
(Figure).
While the decrease of values in systolic and diastolic BPs were significant in all treatment groups at 3, 6 and 12 months after beginning (p<0.001), there was no significant difference among treatment groups.

Conclusions:
This study shows that both of the new generation BBs can be more effective than irbesartan in the regression of LVH due to hypertension. However, there is no significant difference between N and C treatments. Still, the results should be supported by other prospective and randomized studies.
Abstract 130: Are There Gender Differences in Systolic and Diastolic Blood Pressure for Stroke Patients at Presentation to Paramedics After Calling 911?
Authors: El Sanadi Nabil , Grant Shannon , Heiser John , Heiser Tim , Mansour Jason , Engebretsen Labbe Trine , Thornton Gabriel
Published: March 2022

Introduction:
There is a paucity of data on the prehospital presentation of stroke patients. Our assumption was that there are gender differences in S.B.P. and D.B.P. when paramedics first arrive at the scene to evaluate patients with acute non-traumatic cerebral deficit. According to the 2010 A.H.A. guidelines blood pressure elevation should not be treated acutely in the pre-hospital setting.

METHODS:
A retrospective review of run sheets was conducted to determine age, race, sex, initial blood pressure, onset of symptoms and whether the patients were being treated for hypertension. Minitab 16 was used to analyze the data. 2 sample poison test was used to compare groups.

Results:
•214 total records were reviewed •There were 142 Caucasian, 63 Afro-American and 6 Hispanic patients •The initial presenting E.K.G. rhythm was a. Fib in 14 patients, N.S.R. in 186 patients and a paced rhythm in 11 patients •All 209 patients were transported to stroke receiving hospitals without untoward consequences •46 patients called 911 more than 3.5 hrs after the onset of symptoms

51/117 (43%) of women were on antihypertensive agents. 45/92 (48%) of men were on antihypertensive agents.

Conclusions:
For patients who call 911 after the onset of a non-traumatic acute cerebral deficit: there is no difference between men’s and women’s systolic and diastolic blood pressures; despite a significant difference in age and significant variation in treatment regiments for high blood pressure prior to the onset of symptoms.
Abstract 131: Augmenting Cerebral Blood Flow using Military Anti-Shock Trousers: A Transcranial Doppler Study
Authors: Rahman Shakib H , Shuaib Ashfaq , Saqqur Maher
Published: March 2022

Background:
Augmenting blood flow through iatrogenically raising blood pressure is one mechanism to augment cerebral blood flow (CBF) which confers benefits to ischemic brain tissue. CBF augmentation has potential applications in acute ischemic stroke to increase collateral flow. The MAST device has previosuly been used to in a cardiac setting to increase cardiac output and raise blood pressure which can increase systemic flow velocities. The aim of this study was to use the MAST device to augment CBF in healthy subjects.

METHODS:
In this study 11 healthy volunteers (22 vessels) were given MAST which was inflated while simultaneously measuring heart rate, systolic and diastolic blood pressure. Transcranial Doppler (TCD) was used to measure the flow velocities in the middle cerebral artery (MCA) including peak systolic velocity (PSV), end diastolic velocity (EDV), mean flow velocity (MSV) and to calculate pulsility index (PI) over a 4 minute inflation and 2 minute deflation protocol in the supine position.

Results:
After inflation of MAST there was an increase in both systolic and diastolic blood pressure and a slight decrease in PSV (74 vs. 72 cm/s), EDV (33 vs. 32 cm/s) and MFV (50 vs. 49 cm/s) and an increase in PI (0.83 vs. 0.85). After deflation of the MAST device, blood pressure decreased and there was a slight decrease in MFV (49 vs. 48 cm/s) and EDV (32 vs 31 cm/s). PSV was slightly increased (72 vs. 74 cm/s) while PI was greatly increased (0.82 vs. 0.86). Interestingly, two groups were identified based on early and late changes in PI after MAST inflation.

Conclusion:
This data suggests that an artificial increase in blood pressure can augment CBF parameters (PSV, EDV, and MFV) and this change is short lived after an increase in blood pressure. A drop in blood pressure will also change CBF parameters, and importantly increase PI as suggested by Doppler waveforms. Cerebrovascular motor reactivity occurs quickly after changes to blood pressure and works to maintain a constant CBF through the MCA.
Abstract 136: Changes of Myocardial Contractility in Hypertensive Patients With Persistent Atrial Fibrillation Receiving Propafenone
Authors: Mohammadi Leila , Podzolkov Valeri , Tarzimanova Ayda , Pisarev Mikhail , Loriya Irakli
Published: March 2022

Objective:
To study the effect of propafenone 450 mg daily on myocardial contractility in hypertensive patients with persistent atrial fibrillation (AF).

METHODS:
Study included 32 hypertensive patients with persistent AF, aged from 39 to 63 years (median age 58,6±5,3 years), 14 of them (44%) were men and 18 (56%) were women. Sinus rhythm was restored within 24 hours after the oral loading dose of propafenone 600 mg in all the patients. All the patients received propafenone 450 mg daily to prevent AF paroxysms during the next 12 months. Planar equilibrium radionuclide ventriculography was performed in all the patients to assess myocardial function. Initial study was performed in 32 (100%) patients within the first 3 days after sinus rhythm restoration, the follow-up imaging study was carried out in 18 (56%) patients with sustained sinus rhythm after 12 months.

Results:
After 12 months of treatment with propafenone, 18 (56%) of hypertensive patients remained in sinus rhythm. Recurrent episodes of AF were registered in 14 (44%) patients during 12 month follow-up period, hence they were excluded from the study. Initial radionuclide ventriculography made after sinus rhythm restoration in hypertensive patients with persistent AF demonstrated myocardial diastolic dysfunction manifested as significant decrease of time to 30% filling and peak LV and RV filling rate. Follow-up study after propafenone treatment during 12 months revealed significant increase in time to 30% filling and peak LV and RV filling rate. Normal values of atrial contribution to left and right ventricular filling were observed in patients maintaining sinus rhythm during 12 month treatment period with propafenone (p<0.05). Systolic parameters and volume of both ventricles remained normal and showed no significant changes. Left and right ventricular ejection fraction before the treatment start and after propafenone administration during 12 months remained within the normal range.

Conclusion:
Propafenone 450 mg daily administered for recurrent AF prevention does not affect left and right ventricular contractility. Sinus rhythm maintenance for 12 months in hypertensive patients with persistent AF restores atrial contractility and improves ventricular diastolic function.
Abstract 137: Nuclear factor kappa B (NFκB) activation Impairs Vascular Endothelial Function in Type 2 Diabetic Mice
Authors: Kassan Modar , Choi Soo-Kyoung , Galán Maria , Partyka Megan , Bishop Alex , Umezawa Kazuo , Trebak Mohamed , Matrougui Khalid
Published: March 2022

Rationale and Objective:
Type 2 diabetes (T2D) is associated with vascular dysfunction. We hypothesized that increased nuclear factor kappa B (NFκB) signaling contributes to vascular dysfunction in T2D.

Methods and results:
Type 2 diabetic (db
-
/db
-
) and control (db
-
/db
+
) mice were treated with two NFκB inhibitors (DHMEQ, 6mg/kg, twice a week and IKK-NBD peptide, 500μg/kg/day) for four weeks. Pressure-induced myogenic tone (MT) was significantly potentiated, while endothelium-dependent relaxation (EDR) was impaired in coronary arteriole (CA), mesenteric resistance artery (MRA) and aorta from diabetic mice compared to control. Interestingly, diabetic mice treated with NFκB inhibitors significantly reduced MT potentiation and improved EDR. Importantly, vascular function was also rescued in double knockout mice between db
-
/db
-
and NFκB-p50
-/-
(db
-
/db
-p-50NFκB-/-
) and PARP-1
-/-
(db
-
/db
-PARP-1-/-
) compared to db
-
/db
-
mice. In addition, the acute in vitro down regulation of NFκB-p65 using shRNA-lentivirus-p65 in arteries from db
-
/db
-
mice also improved vascular function. The NFκB inhibition did not affect blood glucose and body weight. The expression of Sp-1 was decreased in diabetic mice and restored with NFκB inhibition. Western blot analysis revealed a decrease in eNOS phosphorylation, and an increase in
p65
-NFκB phosphorylation, cleaved PARP-1 and COX-2 expression in arteries from diabetic mice, which were rescued after NFκB inhibition and in db
-
/db
-p-50NFκB-/-
and db
-
/db
-PARP-1-/-
mice.

Conclusion:
In the present study, we provided evidence that enhanced NFκB activity impairs vascular function by PARP-1, Sp-1 and COX-2-dependent mechanisms in male type 2 diabetic mice. Therefore, NFκB could be a potential target to overcome diabetes-induced vascular dysfunction.
Abstract 142: Vascular Function in Himalayan Healthy High-Altitude Dwellers
Authors: Bruno Rosa Maria , Pratali Lorenza , Cogo Annalisa , Pomidori Luca , Duo Enrico , Bartesaghi Manuela , Sharma Ramesh , Thapa Kamal , Basnyat Buddha , Ghiadoni Lorenzo , Taddei Stefano , Picano Eugenio , Sicari Rosa
Published: March 2022

Purpose:
Endothelial function and carotid intima-media thickness (IMT), are established markers of vascular aging. Aim of the study was to investigate the presence of early markers of atherosclerosis in rural Sherpa population of Kumbu Valley (Nepal), in comparison with lowlanders Caucasian subjects.

Methods:
99 Sherpa subjects, living at 2500-3800 m s.l. (34±12 years, BMI 24±3 kg/mq, mean BP 88±9 mmHg), free of cardiovascular disease and risk factors, were recruited, and compared to 60 Caucasian sea-level healthy volunteers (36±12 years, BMI 23±2 kg/mq, mean BP 86±8 mmHg). Endothelial function in the brachial artery (flow-mediated dilation, FMD, and response to glyceryl trinitrate, GTN), and carotid IMT were measured by automated edge-detection system. Left and right ventricular (LV and RV) systolic and diastolic function and pulmonary systolic pressure (PASP), and pulmonary vascular resistance (PVR) were evaluated by echocardiogram. In 11 subjects with reduced FMD, the protocol was repeated, after 100% O
2
administration for 1 hour, titrated to maintain O
2
saturation around 100%.

Results:
High-altitude group presented higher heart rate and lower pulse pressure than sea-level group. FMD was also reduced (5.2±3.1 vs 6.8±3.0%, p=0.01), despite similar brachial artery diameter (3.7±0.6 vs 3.6±0.7 mm, p=0.64), and response to GTN (8.3±3.1 vs 7.6±2.2%, p=0.13). Conversely, IMT was lower in high altitude group than in the sea-level group (0.51 vs 0.61 mm, p<0.001). Sherpa people showed normal LV and RV systolic and diastolic function, PASP(28±6 mmHg) and PVR (0.16±0.4). In the overall population FMD (5.2±3.1%) was not correlated to O
2
saturation (r=-0.03, p=0.74) and was similar in people with O
2
saturation >90% and in those <90% (5.3 vs 5.0%, p=0.74). In the subgroup receiving O
2
administration, FMD (from 3.1±2.5 to 3.8±2.6, p=0.46), response to GTN (from 8.9±2.7 to 8.7±1.9%), and echocardiographic parameters remained unchanged.

Conclusions:
Endothelial function is reduced in healthy Sherpa high-altitude dwellers, in the presence of normal RV and LV function and pulmonary pressures, independently of cardiovascular risk factors and hypoxia. This finding is accompanied with a lower IMT and might represent a physiological adaptation to high altitude.
Abstract 148: Are Disease Management Programs Associated With adherence to JNC-7 Hypertension Guidelines? A nationally representative Analysis Using the 2007 National Ambulatory Medical Care Survey
Authors: Hansen Jonathan D , Harvey Katherine L , Flesche Jan B , Mittleman Murray A
Published: March 2022

Adherence to evidence-based treatment guidelines like JNC7 can improve hypertension outcomes. Identifying factors associated with adherence is important. Disease management programs (DMP) enroll patients and healthcare providers to set management goals, examine progress and receive feedback from members of the healthcare team. DMP enrollment has shown to improve clinical outcomes for diabetes, hypertension (HTN), and hyperlipidemia. We assessed the hypothesis that DMP enrollment is associated with adherence to JNC7 recommendations of lifestyle modification for pre-HTN or appropriate medications for stage 1 or stage 2 HTN. We analyzed nationally representative data from the 2007 National Ambulatory Care Survey that captures patient visit information from ambulatory care services across the US. Our study sample included men and non-pregnant women, > 18 years old, with a diagnosis of HTN, and a recorded blood pressure. JNC7 class was assigned by recorded blood pressure. We examined the association of enrollment in a DMP with the recommendation of lifestyle modifications and provider prescription of indicated drug class per JNC7. Overall JNC7 adherence was determined by using a composite endpoint defined as lifestyle adherence for pre-HTN and drug class adherence as specified by JNC7 guidelines. Logistic regression incorporated survey weights to reflect a nationally representative sample. Our study population was obtained from 32,778 visits in the NAMCS representing 170 million patient visits. The mean age was 63.4 years, 55.0% women and 15.4% of the patient visits were enrolled in a DMP. After adjusting for sex and age, pre-HTN patients enrolled in a DMP had 4.36 times the odds of utilizing lifestyle modifications [95% CI 3.01, 6.32]; DMP enrolled patients had 1.95 times the odds of being adherent to their specific JNC7 drug class guideline [95% CI 1.42, 2.68]; and 2.69 times the odds of being overall JNC7 adherent compared to those who were not enrolled [95% CI 2.06, 3.50]. Enrollment in a DMP is associated with improved adherence to lifestyle interventions in pre-HTN patients and drug adherence in patients with indicated drug class therapy. It is reasonable to consider outcome improvement from improved adherence to evidence based guidelines.
Abstract 155: Female Sex Hormones Blunt Renal Pro-inflammatory T Cell Infiltration Compared to Males
Authors: Tipton Ashlee J , Baban Babak , Sullivan Jennifer C
Published: March 2022

Lymphocytes contribute to hypertension in male spontaneously hypertensive rats (SHR); data in females is lacking, yet young females have a lower blood pressure compared to age-matched males. We hypothesized that 12 week old female SHR have less T cell infiltration and cytokine expression in the kidney compared to males. Kidneys were isolated from male and female SHR and normotensive Wistar Kyoto rats (WKY) and the T cell profile was determined using analytical flow cytometry. In both sexes of SHR, all T cell subtypes and cytokines measured were significantly higher in the kidney compared to the same sex WKY (p<0.05, n=6-8). Male SHR had greater CD4
+
T cell infiltration vs. female SHR (p<0.0001), whereas the CD8
+
T cell numbers were higher in female SHR (p=0.0114). Analysis of T cell subpopulations showed female SHR has greater expression of regulatory T cells (Foxp3
+
CD4
+
CD3
+
) than male SHR (p=0.0008), however, male SHR had more infiltrating pro-inflammatory Th17 cells (RORγ
+
CD4
+
CD3
+
; p<0.0001). Male SHR also had greater expression of pro-inflammatory cytokines, IL-17 and IL-6, on cells in the kidney than females, but female SHR expressed more IL-10, an anti-inflammatory cytokine (p<0.0001, all). Gonadectomy of female SHR significantly increased total T cell (CD3
+
; p=0.0009, n=3-6), CD4
+
T cell (p=0.0010) and Th17 cell (p=0.0025) infiltration into the kidneys. Infiltration of CD8
+
and Foxp3
+
cells remained comparable between groups. Together these data suggest that hypertension in both sexes are associated with an increase in renal inflammatory markers; however female SHR have a more anti-inflammatory profile vs. males which may contribute to their lower blood pressure.