bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 292: Cardiocirculatory Effect of the Increase of Parasympathetic Function with Pyridostigmine in Spontaneously Hypertensive Rats (SHR).
Authors: Lataro Renata M , Silva Carlos A , Fazan Rubens , Salgado Helio C
Published: July 2021

The improvement of parasympathetic function seems to be an attractive therapeutic target in hypertensive patients. The parasympathetic function can be augmented by acetylcholinesterase inhibition. We investigated the chronic effect (16 weeks) of the acetylcholinesterase inhibitor pyridostigmine (PYR) on the hemodynamics [arterial pressure (AP) and heart rate (HR)], autonomic balance (parasympathetic tone, AP and pulse interval (PI) variability), spontaneous baroreflex sensitivity and cardiac function during the development of hypertension in SHR. PYR administration (minipumps, 1.5 mg/kg/day,n=6) started with SHR aging 5 weeks. Control SHR (n=7) was implanted with empty minipump. Mean AP (MAP, mmHg) was monitored every 4 weeks, by the tail-cuff method. At the end of 16 weeks, mean femoral AP (mmHg) was recorded in conscious state and methyl atropine allowed the evaluation of the vagal tone (bpm), while the combined administration of propranolol provided the intrinsic heart rate (IHR, bpm). Cardiac function was assessed, under isofluorane anesthesia, 24h after the hemodynamic recordings. PYR reduced the MAP during the first 8 weeks only (166±6 vs 185±6 in control), while after 16 weeks PYR produced: no change in HR (334±10 vs 354±13 in control); increase in vagal tone (132±8 vs 73±9 in control) and IHR (381±8 vs 340±3 in control); reduction of AP variance (42±6 vs 71±9 in control) without change of PI variance (69±12 vs 73±9 in control); no change of spontaneous baroreflex sensitivity (1.66±0.2 vs 1.75±0.1 bpm/mmHg in control); increase of the ejection fraction (65±5 vs 46±2 % in control). Nevertheless, it was not observed significant changes in cardiac output (32±5 vs 25±3 ml/min in control), +dPdt (9731±1079 vs 8746±461 mmHg/s in control), -dPdt (-9782±1079 vs -11195±1494 mmHg/s in control) and total peripheral resistance index (1.75±0.3 vs 2.53±0.5 mmHg/ml/min in control). In conclusion, PYR reduced the MAP of the SHR only at the beginning of the treatment (8 weeks), although chronically (16 weeks) increased cardiac vagal tone and IHR while reduced the AP variability combined with an increased ejection fraction. Therefore, the increase in parasympathetic function provided only slight benefic effects during the development of hypertension in SHR.
Abstract 297: Chronic Antihypertensive Effects of Sodium Nitrite in L-name-induced Hypertension in Rats
Authors: Amaral Jefferson H , Montenegro Marcelo F , Pinheiro Lucas C , Ferreira Graziele C , Tanus-Santos Joséduardo
Published: July 2021

Dietary nitrite and nitrate have been recently implicated as an important source of nitric oxide with antihypertensive effects. We have previously shown acute antihypertensive effects exerted by a single oral dose of sodium nitrite (NaNO
2
) in renovascular hypertension. However, the possible chronic antihypertensive effects of NaNO
2
have not been examined yet. We evaluated the effects of NaNO
2
on L-NAME (Nω-Nitro-L-arginine methyl ester)-induced hypertension in Wistar rats.

METHODS:
Rats received vehicle (tap water) or L-NAME (1g/L) in their drinking water. After two weeks of treatment, the rats received NaNO
2
(15 mg/kg/day by gavage) or vehicle for 4 weeks. Systolic blood pressure (SBP) was evaluated by pletismography weekly. Plasma levels of nitrate and nitrite were assessed by Griess reaction and ozone-based chemiluminescence, respectively. Dihydroethidium (DHE) was used in aortic sections to evaluate reactive oxygen species (ROS) production by fluorescence microscopy.

Results:
while NaNO
2
treatment induced no changes on SBP in vehicle-treated rats (p>0.05), this treatment significantly reduced SBP in L-NAME-treated rats (192±2 mmHg in L-NAME + vehicle group
versus
164±2 mmHg in L-NAME + nitrite group; P<0.05). At the end of treatment, we found lower plasma nitrite levels in L-NAME rats compared with normotensive controls (148±14 nM
versus
445±97; P<0.05). NaNO
2
treatment increased plasma nitrite levels in both normotensive controls and in L-NAME-treated rats (P<0.05). While no significant changes were found in plasma nitrate levels in L-NAME-treated rats when compared with controls (903±157 nM
versus
995±145; p>0.05), NaNO
2
treatment induced significant increases in plasma nitrate levels in both normotensive and hypertensive rats (191±13 nM and 199±17 respectively; p<0.05 when compared to the controls). When compared to the control groups, higher ROS levels were found in the aortic rings from L-NAME treated rats (4091±249 A.U.
versus
5709±598 A.U.; p<0.05) but treatment did not affect this increase (p>0.05).

Conclusion:
Our results show for the first time that NaNO
2
has relevant chronic antihypertensive effects in L-NAME hypertension. However, was unable to reverse the oxidative stress associated with L-NAME-induced hypertension.
Abstract 30: Urinary Exosome miRNome Analysis and its Application to Salt-Sensitivity of Blood Pressure
Authors: Carlson Julia M , Gildea John J , Schoeffel Cynthia D , Carey Robert M , Felder Robin A
Published: July 2021

Definitive biomarkers are needed in order to improve diagnostics for salt-sensitivity of blood pressure and hypertension. Exosomes are small vesicles, 50-90 nm in diameter, released from renal tubular epithelial cells into urine, which may contain sub-cellular components that could serve as diagnostic biomarkers. Total miRNA (miRNome) in urinary exosomes has not been previously examined for disease biomarkers, particularly for hypertension and/or salt sensitivity. Following ultracentrifugation of urine, total RNA was collected from urinary exosomes and analyzed by array analysis by LC Sciences (miRBase Human version 18). Three samples per individual of urinary exosomes were isolated and pooled from five human subjects previously typed for salt-sensitivity index from a prior clinical study using a two week controlled sodium diet. Patients were stratified according to salt sensitivity status: High salt-sensitive (HSS) patients’ mean arterial blood pressure (MAP) increased on high salt diet by >7mmHg, low salt-sensitive (LSS) patients MAP increased on low salt diet by >7mmHg, and salt-resistant (SR) patients MAP changed <7mmHg between the high and low salt diet. 306 miRNA targets out of 1898 probes were above background providing the first data for urinary exosome miRNome in humans (n=5). Bioinformatic analysis determined 20 significant differences in miRNome patterns between the HSS, SR, and LSS individuals (n=4, P<0.01). These data demonstrate the first examination of the urinary exosomal miRNome as it relates to sodium-induced blood pressure changes and suggest that it may constitute a convenient diagnostic test for salt-sensitivity of blood pressure.
Abstract 300: Oral Administration of Lentil Extracts Attenuated Angiotensin Ii-induced Cardiac Hypertrophy and Hypertension in Normotensive Rats
Authors: Xuan Chengluan , Yao Fanrong , Guo Lirong , Chang Sam , Liu Kexiang , Sun Chengwen
Published: July 2021

The objective of this study is to examine the effects of extracts from raw and cooked lentil on angiotensin II (Ang II)-induced cardiac hypertrophy, fibrosis, and hypertension in normotensive rats. Subcutaneous infusion of Ang II (200 ng/kg/min) using osmotic minipump significantly resulted in the elevation of blood pressure measured using telemetry in conscious rats. Histological examination revealed that Ang II infusion for 4 weeks induced significant cardiac hypertrophy, perivascular fibrosis in the heart and kidney. Rats received lentil extracts (oral administration for 4 weeks) significantly attenuated Ang II-induced elevation in blood pressure, cardiac hypertrophy, perivascular fibrosis. To examine whether the protective effect of lentil extracts on cardiac hypertrophy is mediated by attenuation of blood pressure or directly act on the cardiomyocytes, we examined the effect of lentil extracts on Ang II-induced hypertrophy in cultured cardiomyocytes. The result demonstrated that pretreatment of cardiomyocytes with cooked or raw lentil extract significantly attenuated the Ang II-induced increases in the size of cells. In addition, these lentil extracts also attenuated Ang II-induced increases in the ROS levels in cardiomyocytes. In summary, the results demonstrate that extracts from cooked or raw lentil prevent Ang II-induced elevation in blood pressure, perivascular fibrosis, and cardiac hypertrophy. The cardiac protective effect on Ang II-induced cardiac hypertrophy may be mediated by a direct action in cardiac tissue via reduction of oxidative stress.
Abstract 303: Effect of a Resistance Training Period on Blood Pressure, Circulating Levels of Interleukine-6, Quality of Life and Functional Capacities in Elderly Hypertensive Patients
Authors: Montrezol Fábio T , Medeiros Alessandra
Published: July 2021

The aging increases susceptibility to hypertension, and also promotes muscle wasting, thereby increasing the risk of falls within the elderly. In contrast, the resistance training (RT) is recommended for increasing or maintaining muscle strength levels in the elderly. However, there is still no consensus in the literature about its effectiveness for hypertension treatment. Therefore, the aim of this study was to verify the effect of RT on blood pressure, circulating levels of Interleukine-6 (IL-6), quality of life and functional capacities in elderly hypertensive patients.

Methods
43 subjects were randomized in two groups: sedentary (S) and RT. The RT was practiced during 14 weeks in three non-consecutive days per week, with 50% of 1 maximal repetition of intensity. Before and after experiment period were evaluated blood pressure by ambulatory blood pressure monitoring (ABPM), IL-6 by ELISA kit, quality of life by questionnaire (SF-36) and functional capacities by battery of functional tests. Data were analyzed using ANOVA two-way (p≤0.05).

Results
The S group showed no statistical differences in ABPM, IL-6, SF-36 and functional testing, pre and post experiment. On the other hand, the RT group had significant reductions in systolic blood pressure within 24 hours (125 ± 2; 120±3 mmHg pre and post, respectively), day-time (127±2; 123±3 mmHg pre and post, respectively) and morning-time (125±4; 118±3 mmHg pre and post, respectively), diastolic blood pressure in 24-hours (69±1; 66±1 mmHg pre and post, respectively), night-time (64±1; 59±1 mmHg pre and post, respectively) and morning-time (69±2; 66±1 mmHg pre and post, respectively), mean blood pressure in 24-hours (91±1; 86±2 mmHg pre and post, respectively), day-time (93±1; 89±2 mmHg pre and post, respectively) and morning-time (87±2; 84±2 mmHg pre and post, respectively). In the SF-36, the RT group improved its results in all categories, which was also observed in the functional tests. The RT group showed a trend towards reduction in IL-6, which was not observed in the S group.

Conclusion
A period of resistance training lowered blood pressure and improved quality of life and functional capacity of elderly hypertensive patients.

Acknowledgements: FAPESP 2011/23830-3
Abstract 309: Role of Hemeoxygenase in the Reno-Protective Effects of Soluble Epoxide Hydrolase Inhibition In Diabetic Spontaneously Hypertensive Rats
Authors: Elmarakby Ahmed A , Faulkner Jessica , Pye Chelsey , Baban Babak , Rouch Katelyn , Alhashim Abdulmohsin , Maddipati Krishna R
Published: July 2021

We previously showed that inhibition of soluble epoxide hydrolase (sEH) increased epoxyeicosatrienoic acids (EETs) levels and reduced renal injury in diabetic mice and these changes were associated with induction of hemeoxygenase-1 (HO-1). The present study determines whether the inhibition of HO negates the reno-protective effect of sEH inhibition in diabetic spontaneously hypertensive rats as a model of diabetic nephropathy in which hypertension coexists with diabetes. After six weeks of induction of diabetes with streptozotocin, SHR were divided into the following groups: untreated, treated with the sEH inhibitor,
trans
-4-[4-(3-adamantan-1-yl-ureido)-cyclohexyloxy]-benzoic acid (AUCB), treated with the HO inhibitor, stannous mesoporphyrin (SnMP), and treated with both inhibitors for four more weeks; non diabetic SHR served as a control group. Although inhibition of sEH increased renal EETs/DHETEs ratio and HO-1 activity in diabetic SHR, it did not significantly alter blood pressure (plasma EETs/DHETEs ratio was 0.5± 0.1 in AUCB-treated
vs.
0.1± 0.01 in untreated diabetic SHR, P<0.05). Treatment of diabetic SHR with AUCB reduced the elevation in urinary albumin and nephrin excretion (albuminuria was 6.5± 0.5 in AUCB-treated diabetic SHR vs. 9± 1.7 mg/day in untreated diabetic SHR and nephrinuria was 70±11 in AUCB-treated diabetic SHR vs. 111± 9 μg/day in untreated diabetic SHR, P<0.05) whereas co-administration of SnMP with AUCB prevented these changes (albuminuria was 10.6± 0.6 mg/day and nephrinuria was 91±11 μg/day). Immunohistochemical analysis revealed elevations in renal fibrosis and apoptosis as evidenced by increased renal TGF-β, fibronectin and annexin V expression in diabetic SHR and these changes were reduced with sEH inhibition. Co-administration of SnMP with AUCB prevented its ability to reduce renal fibrosis and apoptosis in diabetic SHR. In addition, SnMP treatment also prevented AUCB-induced decreases in renal macrophage infiltration and renal TGF-β, NFκB and MCP-1 levels in diabetic SHR. These data suggest that HO-1 induction is involved in the protective effect of sEH inhibition against diabetic renal injury.
Abstract 311: Facilitators and Barriers to Self-management of Patients with Type 2 Diabetes in Communities in China, a Qualitative Study
Authors: Chen Xiang Y , Yue Peng , Wang Yong L , Xiao Shu Q , Feng Xin W , Wu Ying
Published: July 2021

Background:
Self-management has become a key strategy for caring chronic patients in community. However, little is known about peoples’ self-management experiences and their perceived cues and barriers to engagement in self-management.

Objective:
To explore issues patients with type 2 diabetes experienced in their self-management practices,to understand cues and barriers to engagement in self-management. Design: Qualitative study (Semi-structured interviews) Setting: 11 communities in Beijing, China Participants: Type 2 diabetes patients in community, aged >18, no admission in past 90 days.

Methods:
40 critical incident interviews were run during Apr to Sep in 2011 using purposive sampling (20 interviews with patients whose HbA1c well-controlled (<6.5%), while 20 badly-controlled (≥8%)).Themes from interviews were identified using content analysis, which revealed cues and barriers to self-modification for diabetes management.

Results:
Implications for self- management practice included objectively understanding on the severity and complications of diabetes. In addition to family support such as supervision in family and fully-use of family resource, desires/duties to be responsible for whole family life as a breadwinner was emerged as a key cue to engagement in self-control. Barriers to engagement in self-management stemmed from financial burden to monitor blood glucose daily, dissatisfaction of HbA1c level after efforts, and malignant life events. It is worth mentioning that starving experience of difficult time with natural disasters in1960s- 1970s in China was identified also as a key barrier to engagement in diet management.

Discussion and Conclusion:
There was a strong desire for Chinese patients to comply with Chinese cultural norms; particularly those relating to family value. It was the patients’ power to be involved in self-management that they could devote their healthy life to family duty. Everyone had his/her own history so experiences in past shaped patients’ behaviors now. The findings highlighted the importance of understanding the family value and the personal experiences as facilitators and barriers to self-management of Chinese patients with type 2 diabetes living in community.
Abstract 317: ACE2 Deficiency Enhances Angiotensin II-Induced Vasoconstriction Of The Uterine Artery at Mid-Gestation In Mice.
Authors: Yamaleyeva Liliya M , Lindsey Sarah H , Pulgar Victor M , Yamane Larissa , daSilva Mauro , Bonfa Paula , Brosnihan K. Bridget
Published: July 2021

Fetal growth restriction (FGR) remains a leading cause of perinatal morbidity and mortality in humans. Angiotensin converting enzyme 2 (ACE2) is a key enzyme of the renin-angiotensin system that influences the balance between angiotensin II (Ang II) and angiotensin-(1-7) (Ang-(1-7)). ACE2 is highly expressed in the human placenta and maternal stromal tissue in normal pregnancy; however its role in pregnancy is not well understood. Our previous studies revealed that pregnancy in ACE2-deficient mice (ACE2KO) is associated with restricted maternal and fetal weight, attenuated circulating Ang-(1-7), and increased placental Ang II at the end of pregnancy. Since the loss of ACE2 may lead to vascular dysfunction and FGR, we compared the uterine artery reactivity in ACE2KO versus wild-type C57Bl/6 (WT) pregnant mice using wire myography. Maternal and fetal weights and pup-to-placenta ratio were not altered in ACE2KO at day 14 of gestation. However, the number of pups was reduced in ACE2KO [ACE2KO: 7.2±0.2 vs. WT: 9.8±0.7 pups, n=4-5; *p<0.05]. Uterine artery diameters were similar between the two mouse strains. Maximal vasoconstriction to 10 μM phenylephrine (PE) or 80 mM potassium chloride (KCl) and maximal endothelium-dependent relaxation (1 μM acetylcholine) were not altered in pregnant ACE2KO versus pregnant WT. Pregnancy tended to reduce the uterine artery sensitivity to Ang II in WT [virgin: LogEC50: -9.0 vs. 14d pregnant: -8.0, p=0.09], but not in ACE2KO [virgin: LogEC50: -9.1 vs. 14d pregnant: -8.6, p=0.46]. Moreover, the concentration-dependent vasoconstriction to Ang II (0.1 nM-1 μM) was greater in the uterine arteries from pregnant ACE2KO as compared to pregnant WT [ACE2KO: LogEC50: -8.6 vs. WT: -8.0, n=4-5; *p<0.05]. Pretreatment with 1μM Ang-(1-7) for 5 minutes partially attenuated the Ang II-induced vasoconstriction and tended to reduce the sensitivity to Ang II in pregnant ACE2KO [n=2-4]. These results show that the loss of ACE2 in pregnancy is associated with increased constriction and sensitivity of the uterine artery to Ang II. Absence of enhanced constriction to PE or KCl in ACE2KO suggests the specificity of the Ang II-induced response. In conclusion, ACE2 deficiency may contribute to FGR via Ang II-mediated uterine artery dysfunction.
Abstract 32: A Rapid Method for Clinical Diagnosis of Salt Sensitivity of Blood Pressure
Authors: Gildea John J , Lahiff Dylan T , Keene Staci A , Van Sciver Robert E , Carey Robert M , Schoeffel Cynthia D , Felder Robin A
Published: July 2021

Salt-sensitivity of blood pressure (BP) is a cardiovascular risk that affects 25% of the world’s population due to its resulting hypertension, although independent of BP. Salt-sensitivity is detected with a two week controlled diet, which is difficult to administer in the clinical setting. We therefore developed a rapid method of diagnosis based on exfoliated renal proximal tubule cells (RPTC) in urine. Subjects were divided into 3 salt sensitivity index categories: High-Salt-Sensitive (HSS; ≥ 7 mmHg increase in mean arterial pressure (MAP) on a high salt diet of 300 mEq of sodium, 17%prevalence), Low-Salt-Sensitive (LSS; ≥ 7 mmHg increase in MAP on a low salt diet of 10 mEq of sodium, 11% prevalence) and Salt Resistant (SR; ≤ 7 mmHg increase in MAP on both high and low salt diets, 72% prevalence) (Carey et al., in review). Three individuals were analyzed in each category on a minimum of 3 separate occasions. Cells were isolated from urine using centrifugation and measured for dopamine-1 receptor (D1R) plasma membrane recruitment using fluorescently-labeled antibodies under a confocal microscope as well as in a flow cytometer. Confocal microscopy analysis (total of 100 RPTCs for the 9 subjects) showed a negative correlation between salt-sensitivity index and D1R surface recruitment in RPTCs in their response to salt stimulation (y = -0.0073x + 0.5248, p = 0.0159). Flow cytometry analysis (total of 4938 RPTCs for the 9 subjects) also demonstrated a negative correlation between salt-induced D1R recruitment and salt-sensitivity (y = -2.547x + 239.97, p < 0.0001). Flow cytometry analysis showed a greater degree of separation amongst the subjects than confocal microscopy analysis, and would allow for a rapid diagnostic use of exfoliated renal cells in urine. Cryopreserved RPTCs (viability = 57.16% ± 9.15%, n = 12) compare favorably with cell viability from freshly voided urine cells and were still capable of eliciting intracellular sodium-mediated D1R recruitment. Cryopreservation thus enables batch collection, transport and processing of specimens between sites. We expect these procedures to provide a novel and convenient method of diagnosing the salt-sensitivity index in humans.
Abstract 324: In Vivo Cross-talk Between Mineralocorticoid Receptor and Ang-(1-7) Enhances Ca2+ Signaling in Ventricular Myocytes
Authors: Almeida Pedro , Lima Ricardo d , Santiago Nivia M , Gavioli Mariana , Mitraud Luciana , Greco Leonardo , Alves Márcia N , Nocchi Eduardo , Parreira Amanda B , Resende Rodrigo R , Melo Marcos B , Santos Maria José , Santos Robson A.S. Santos A , Guatimosim Silvia
Published: July 2021

Mineralocorticoids have been implicated in the pathogenesis of cardiac diseases. In contraposition, Angiotensin (Ang)-(1-7) has been shown to attenuate cardiac dysfunction induced by excessive mineralocorticoid receptor (MR) activation
in vivo
, suggesting a possible interaction between these two signaling pathways in the heart. Here, we investigated whether there is a cross-talk between MR signaling and Ang-(1-7) and its consequences for cardiomyocyte function. For this, we used a transgenic rat that overexpress an Ang-(1-7)-producing fusion protein, TGR(A1-7)3292 (TG), which induces an increase in circulating levels of this peptide, treated or not with deoxycorticosterone acetate (DOCA). After six weeks of DOCA-salt, rats presented increased blood pressure and cardiac ejection fraction when compared to SD control rats. Marked cardiac hypertrophy was also observed at six weeks of DOCA-salt treatment. In contrast, TG DOCA rats did not develop cardiac hypertrophy or changes in ventricular function. qPCR analysis of ventricular myocytes from SD DOCA-salt rats revealed a six fold increase in MR and a three fold increase in ß-myosin heavy chain mRNA transcripts. These changes were significantly attenuated in cardiomyocytes from TG DOCA rats. We also examined intracellular Ca
2+
levels in freshly isolated Fluo-4-loaded cells. The amplitude of the [Ca
2+
]
i
transient was reduced in SD DOCA cardiomyocytes (F/F
0
=5.12+ 0.1 n=56 in SD versus F/F
0
=3.75+0.1 n=65 in SD DOCA myocytes, p<0.05). These changes were at least partly explained by reduced SERCA2 protein and altered PLN phosphorylation in these cells. In contrast, TG DOCA cardiomyocytes presented enhanced Ca
2+
transient (F/F
0
=8.02+ 0.2 n=68 myocytes) and increased SERCA2 expression. Cardiomyocytes from TG rats presented Ca
2+
transient comparable to SD cells. SD DOCA rats also showed increased PP1 and PKC alpha expression in comparison to SD and TG DOCA cells. These results suggest that Ang-(1-7) and MR signaling pathways cross-talk to enhance Ca
2+
transient in cardiomyocytes preventing the Ca
2+
signaling dysfunction characteristic of excessive MR activation. These data provide a better understanding of the cardioprotective effects of this putative therapeutic peptide.
Abstract 331: 20-hydroxyeicosatetraenoic Acid is Involved in Angiotensin II-mediated Apoptosis in Rat Cardiac Myocyte
Authors: Han Yong , Shen Xin , Yao Fanrong , Xuan Chengluan , Gu Yan , Qian Steven Y , Zeng Qinghua , Sun Chengwen
Published: July 2021

Cardiomyocyte apoptosis has been documented involved in a variety of cardiac stresses, including ischemia-reperfusion injury, heart failure, and cardiomyopathy. Both angiotensin II (Ang II) and 20-Hydroxyeicosatetraenoic Acid (20-HETE), a hydroxylation product of arachidonic acid catalyzed by CYP450-ω hydroxylase, induce apoptosis in cardiomyocyte. However, the crosstalk between 20-HETE and Ang II in cardiomyocytes apoptosis process is unclear. In the current study, we examined apoptosis using flow cytometry in primary cultured neonatal rat ventricular myocytes treated with control, Ang II (100nM), Ang II plus HET0016 (10μM), HET0016, or 20-HETE (10nM) along. The results demonstrated that treatment with Ang II or 20-HETE significantly increased apoptosis and that Ang II-induced apoptosis were markedly attenuated by HET0016, a 20-HETE agonist. In addition, Ang II-induced increases of caspase-3 activity were significantly attenuated by 20.9±3.4% after co-treatment with HET0016. Our results also demonstrated that HET0016 significantly suppressed Ang II-induced increases of superoxide production by 27.52.3% and mitochondrial membrane potential by 64.5±6.3%. Finally, Ang II-induced nuclei crenation, chromatin condensation and fractionation were attenuated by 73.6±8.5% with HET0016 pre-treatment. In addition, treatment cardiomyocytes with Ang II increased CYP4A1 expression and 20-HETE production, measured by Western blot, real-time RT-PCR, and mass spectrometric analysis. All results suggest that 20-HETE may play a key role in Ang II-induced apoptosis in cardiomyocytes. 20-HETE and 20-HETE-producing enzymes could be novel targets for the treatment of Ang II related cardiac diseases.
Abstract 334: Selective Renal Deafferentation Attenuates the Development of Genetic and Renal Hypertension
Authors: Knuepfer Mark M , Billington Nathan E , Willingham Laura A , Langasek Julie E , Samson Willis K , Westfall Thomas C
Published: July 2021

Renal denervation decreases arterial pressure (AP) in hypertensive rats and humans. This procedure destroys both afferent and efferent nerves. Several investigators have proposed that renal afferent nerves contribute to the elevated AP. We developed a procedure to selectively remove renal afferent nerves with capsaicin (1-100 mM) both topically on the nerve and in the renal pelvis. We examined the effects of renal deafferentation on the development of genetic and renal hypertension. We studied spontaneously hypertensive rats (SHR), and a model of renal hypertension, two kidney-one clip (2K1C) in Sprague-Dawley rats. SHR were treated at 3-4 weeks of age with capsaicin. Mean arterial pressure was recorded by tail cuff through 16 weeks of age. On week 17, rats were cannulated, allowed 3 days to recover then had their AP measured directly for 3 days (3 hrs/day). Rats with renal deafferentation (n=11) had lower arterial pressure weeks 9-16 (average reduction AP=10.1±1.4 mmHg, ANOVA, p=0.0049) compared to control (saline treated, n=6) although the final direct recording was not significantly different on week 17 (control AP=184.1±3.4 mmHg vs deafferented AP=173.9±4.3 mmHg, p=0.07). Substance P levels from the kidneys were reduced in deafferented rats compared to control (6.9±1.0 vs 17.3±5.2 pg/g protein, p=0.0009). In contrast, renal NE levels were not altered (307±19 vs 313±20 pg/g protein, p=0.428). In the second study, the left kidney in weanling Sprague-Dawley rats was exposed to capsaicin or saline. Rats were allowed to mature (>250 g BW) then subjected to left renal artery clipping (0.2mm) or sham clip. AP was recorded by tail cuff during development of 2K1C for 6 weeks before direct cannulation to record AP on week 7. Renal deafferentation prevented the development of hypertension in 13 rats compared to 9 saline treated rats (average reduction AP=16.9±2.7 mmHg, ANOVA, p=0.0031). Saline treated rats had a higher AP 7 weeks after clipping (147.1±10.2 vs 130.5±4.2 mmHg direct recording, p=0.02). The left kidney contained 48% SP compared to the right kidney (p=0.04). These data suggest that increased afferent renal nerve activity contributes to the elevation in AP in hypertension and contributes to essential hypertension in humans. Supported by USPHS DA017371.
Abstract 337: Mechanisms of Reduced Aortic Relaxation Rate in Rats with Adenine-Induced Chronic Renal Failure
Authors: Nguy Lisa , Lundgren Jaana , Nilsson Holger , Guron Gregor
Published: July 2021

We have previously shown that adenine-induced chronic renal failure (A-CRF) in rats causes a pronounced reduction in the rate of relaxation of the thoracic aorta, but not of mesenteric arteries. The aim of this study was to elucidate the mechanisms causing a decreased rate of relaxation in the thoracic aorta of rats with A-CRF and to examine if this abnormality was specific for this vascular bed or comprised also other conductance arteries. Male Sprague-Dawley rats received either chow containing adenine (0.5% week 1-3, 0.3% w. 4-5, and 0.15% thereafter) or were pair-fed an identical diet without adenine (controls). After 8-13 weeks segments of thoracic aorta, abdominal aorta, common carotid artery and common femoral artery were analyzed ex vivo with wire myograph. Data are means±SD. Plasma creatinine levels were markedly elevated in A-CRF animals (306±139 vs. 31±3 μM, P<0.001). The area under the curve for the initial 50 % reduction in force (reflecting relaxation rate) following wash-out of KCl was significantly elevated in A-CRF animals in the thoracic aorta (3.7-fold vs. controls, P<0.01), abdominal aorta (5.6-fold vs. controls, P<0.05), carotid artery (7.0-fold vs. controls, P<0.05), but was not significantly affected in the femoral artery. Removal of endothelium did not affect relaxation rate significantly in A-CRF thoracic aortas. However, aortic relaxation rate increased significantly (P<0.01), but was not normalized, in response to wash-out of KCl with Ca2+-free buffer. Thoracic aortas from A-CRF animals showed an increased sensitivity to KCl (log EC50 values -1.67±0.05 vs. -1.74±0.04 M in controls and A-CRF, respectively, P<0.01) but an unaltered sensitivity to Ca2+ during concentration-response experiments. In conclusion, rats with A-CRF show a pronounced reduction in the rate of relaxation of larger conductance arteries localized proximal to the common femoral artery. This abnormality, which could contribute to increased arterial stiffness, is independent of the endothelium but partly dependent on extracellular Ca2+. The increased sensitivity to KCl in the presence of a normal sensitivity to Ca2+ in A-CRF aortas could indicate that vascular smooth muscle cells of A-CRF aortas are more depolarized but this needs to be investigated further.
Abstract 340: Deletion of Cyp2c44-epoxygenase in the Collecting Duct Causes the Hypertension in Mice on a High K Diet
Authors: Wang WenHui , Lin Dao-Hong , Gone Yan , Yue Peng , Zhang Chengbiao , Capdevila Jorge
Published: July 2021

Previous studies demonstrated that high K (HK) intake caused hypertension in Cyp2c44 (-/-) mice. In the present study we examined the role of Cyp2c44 in the collecting duct (CD) in blood pressure (BP) regulation during increased K intake in a CYP2c44 CD-specific conditional knockout mice (KO). CD specific KO mice were generated by crossing Cyp2c44(flx/flx) mice (a generous gift of from D. Zeldin, MD) with a Hoxb7-Cre+ mice. The KO mice have normal body development and show no visible differences when compared to wt mice. However, increasing dietary K intake from 1% to 4% significantly increased the BP of KO mice (from 125 mmHg to 148 mmHg) but, not that of wt mice. In contrast, feeding KO mice with high salt (4% or 8%) had no significant effect on their BP (126 mmHg). A high (HK) intake also slightly but significantly increased plasma Na concentration of KO mice from 149 mM to 150.3 mM. Moreover, single tubule-real-time PCR experiments demonstrated that a HK intake increased the expression of Cyp2c44 mRNA by 10 folds in the distal convoluted tubule (DCT) but only had a modest effect in the TAL and no effect on Cyp2c44 expression in proximal tubules. Thus, a HK intake is still able to stimulate Cyp2c44 expression in the DCT. Because administration of amiloride decreased the BP of the KO mice on a HK diet to 117 mmHg, we speculate that defective regulation of ENaC by the Cyp2c44 epoxygenase may be responsible for the HK intake-induced hypertension in the KO mice. This speculation was confirmed by patch-clamp experiments performed in the isolated CD of the KO mice. Application of arachidonic acid (AA) inhibited ENaC in the wt mice but failed to inhibit Na channels in the KO mice. However, adding 11,12-EET inhibited ENaC in both wt and KO mice. We conclude that the CD Cyp2C44-epoxygenase in is essential for suppressing ENaC activity in the CD and for preventing hypertension in response to a HK intake.
Abstract 345: Effects of Physical Exercise on Blood Pressure of Patients With Chronic Kidney Disease on Hemodialysis: Meta-analysis of Randomized Clinical Trials
Authors: Scapini Kátia B , Moraes Oscar A , Sbruzzi Graciele , Moraes-Silva Ivana , Leguisamo Camila P , Tourinho Filho Hugo , Krieger Eduardo M , Irigoyen Maria Cláudia C
Published: July 2021

Background:
The incidence of End Stage Renal Disease (ESRD) has increased in recent years. Hypertension is a well described complication of chronic kidney disease. Its incidence in hemodialysis patients is approximately 80% and there is substantial evidence of the relationship between high blood pressure and cardiovascular risk in this population.

Objective:
To systematically review the effects of physical exercise on blood pressure of patients with ESRD undergoing hemodialysis (HD).

METHODS:
MEDLINE, EMBASE, COCHRANE CENTRAL and LILACS databases were searched for trials published between January 1980 and August 2011. Only randomized clinical trials (RCTs) with adult patients diagnosed with ESRD on HD comparing aerobic exercise, resistance training or combined resistance and aerobic training with the control group were eligible. The selection of studies, data extraction and assessment of methodological quality were performed by two independent reviewers. The meta-analysis was conducted using the random effects model.

Results:
Our search found 1.034 articles, from which 12 RCTs (389 participants) met the eligibility criteria and were included. We observed that combined resistance and aerobic training (six RCTs) reduces the systolic (-5.84 mmHg; 95% CI: -9.8, -1.88) and the diastolic blood pressure (-3.90 mmHg; 95% CI: -6.20, -1.60); however, the same was not observed with aerobic exercise (six RCTs) (SBP: -0.84 mmHg, 95% CI: -7.18, 5.51 and DBP: 0.68 mmHg, 95% CI: -3.38, 4.74). Probably, the absence of blood pressure decrease with aerobic exercise was due to the small sample size of those studies, the inclusion of both hypertensive and non hypertensive patients and the lack of information whether there was a control of the dosage of antihypertensive medication during follow-up.

Conclusions:
Combined resistance and aerobic training reduces the blood pressure of ESRD patients on HD and, therefore, can be recommended as an adjuvant non-pharmacological intervention in the treatment of ESRD patients on HD. Sources of Funding: Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Abstract 368: Dynamic Receptor-Ligand Activation of Nox1 Regulates Blood Flow via a Novel TSP1-CD47 Signaling Axis
Authors: Csányi Gábor , Yao Mingyi , Rodriguez Andres I , Al Ghouleh Imad , Sharifi-Sanjani Maryam , Kelley Eric E , Isenberg Jeffrey S , Pagano Patrick J
Published: July 2021

Reactive oxygen species (ROS) play an important role in ischemia-reperfusion injury but the mechanisms controlling this phenomenon remain elusive. Our previous studies demonstrated that matrix protein thrombospondin-1 (TSP1) at concentrations found in human disease (2.2 nM) is a rapid and potent stimulator of superoxide (O2•–) production in vascular smooth muscle cells (VSMC). However, the mechanism by which TSP1 mediates this response and its role in reperfusion-induced impairment of tissue perfusion are unknown. Here, we show that blockade of integrin-associated CD47 signaling (pmol O2•–/mg protein/min: 6.7±0.6, 10.2±0.7*, 6.0±0.5, and 7.1±0.7 for isotype control + vehicle, isotype control + TSP1, CD47 blocking antibody + vehicle and CD47 blocking antibody + TSP1; *p<0.05 vs isotype control + vehicle) and gene silencing of NADPH oxidase 1 (Nox1) abrogated TSP1-stimulated O2•– in VSMC. By luciferase reporter array, we identified myocyte enhancer factor 2 (MEF2) as a downstream effector of TSP1 and show that knockdown of MEF2A suppresses TSP1-stimulated O2•– (pmol O2•–/mg protein/min: 4.2±0.3, 6.3±0.4*, 4.1±0.3, and 4.6±0.3 for scrambled siRNA + vehicle, scrambled siRNA + TSP1, MEF2A siRNA + vehicle and MEF2A siRNA + TSP1;*p<0.05 vs scrambled siRNA + vehicle). Further, TSP1 rapidly phosphorylated the Nox organizer subunit p47phox in VSMC. Electron paramagnetic resonance demonstrated that TSP1 stimulates O2•– in wild type (WT), but not in Nox1y/-, endothelium-free aortic rings (CM• radical formation (x10 3): 20.9±11.1, 86.8±20.5*, 20.2±28.6 and 29.6±22.2 for WT + vehicle, WT + TSP1, Nox1y/- + vehicle, and Nox1y/- + TSP1; *p<0.05 vs WT + vehicle). Finally, intravenous TSP1 acutely decreased recovery of hindlimb blood flow following ischemia-reperfusion as measured by real time laser Doppler in control, but not in Nox1 gene silenced, rats. Our findings suggest a highly-regulated role of matricellular TSP1 as a stimulator of a novel CD47-MEF2A-Nox1 signaling axis and ROS and support a role for the matrix protein as a blood flow attenuator in cardiovascular disease.
Abstract 369: D5 Dopamine Receptor Decreases Reactive Oxygen Species via Heme Oxygenase-1
Authors: Lu Quansheng , Yang Yu , Villar Van A , Asico Laureano D , Jones John E , Yu Peiying , Li Hewang , Eisner Gilbert M , Felder Robin A , Jose Pedro A
Published: July 2021

D5 dopamine receptor (D5R) knock-out mice (D5-/-) have higher blood pressure and reactive oxygen species (ROS) production than their D5R wild-type littermates (D5+/+), related in part to increased NADPH oxidase expression and activity. We tested the hypothesis that the high blood pressure and increased ROS production in D5-/- mice may also be related to decreased heme oxygenase-1 (HO-1) expression and activity. We found that renal HO-1 protein expression and HO enzyme activity were decreased (by 65% and 50%, respectively) in D5-/- relative to D5+/+ mice. A 24 h of administration of hemin, an HO-1 inducer, increased HO-1 protein expression and HO activity (6.8-fold and 1.9-fold, respectively) in D5-/- but not D5+/+ mice and normalized the increased blood pressure and ROS production in D5-/- mice. Expression of HO-1 protein and HO activity were increased (2.3-fold and 1.5-fold, respectively) in HEK cells which heterologously expressed human wild-type D5R (HEK-hD5R) but not empty vector-transfected HEK-293 cells. Fenoldopam (Fen) treatment increased HO-1 protein expression and HO activity and HO-1 and D5R co-localization and co-immunoprecipitation in HEK-hD5R cells. Basal cellular ROS production was decreased by 35% in HEK-hD5R that was abrogated with silencing of the HO-1 gene. HO-1 siRNA also decreased the ability of Fen to decrease ROS production in HEK-hD5R cells. In summary, the D5R positively regulates HO-1 activity through direct protein/protein interaction in the short-term and by increasing HO-1 protein expression, in the long-term. Impaired D5R regulation of HO-1 may be involved in the pathogenesis and maintenance of hypertension in D5-/- mice.
Abstract 380: Myocardial Angiotensin Metabolism Analysis Using Matrix-Assisted Laser Desorption Ionization (MALDI) Imaging
Authors: Alghamri Mahmoud , Grobe Nadja , Elased Khalid , Morris Mariana
Published: July 2021

Mass spectrometric (MS) methods were used to study angiotensin (Ang) metabolism in mouse heart. The focus was on Ang II, Ang-(1-7) and Ang III. Goals were: 1) develop and optimize new technique for in situ assessment of Ang II processing within the myocardium using matrix-assisted laser desorption ionization (MALDI) imaging and 2) to validate results by in vitro MALDI MS enzyme assay as well as specific enzyme inhibitors. This newly developed imaging method has the advantage of allowing for regional spatial visualization and quantification of the formed peptides within the myocardium. Frozen mouse heart sections (12 μm) were incubated with 5 μL of 10-1000 ng/μL Ang II for 5-15 min at 37 °C. The main formed peptides, Ang III and Ang-(1-7), were identified by MALDI-TOF/TOF. Ang-(1-7) was concentrated in the ventricle while Ang III was detected throughout the heart. For the MALDI MS enzyme assay, left ventricular (LV) homogenate was incubated with Ang II at 37 °C. The reaction mixture was spotted on target plate and peptides were detected using MS. Results showed that Ang peptide formation was greatest at 100 ng/μL Ang II with short incubation period. Ang III formation was predominant with Ang III/ Ang II peak intensity 63%, whereas Ang (1-7)/ Ang II peak intensity was 22%. Ang III generation was blocked by the APA inhibitor, glutamate phosphonate (Glu-P), in a concentration dependent manner. The ACE2 inhibitor, MLN-4760, and the PCP/PEP inhibitor, Z-pro-prolinal, reduced myocardial Ang (1-7) formation by 66% (from 70.02 to 23.8 and from 112.7 to 38.3), respectively. Interestingly, blockade of APA by Glu-P caused a 4 fold increase in Ang (1-7)/Ang II ratio. Results validated MALDI imaging for the in situ assessment of Ang II metabolizing enzymes. Ang II is mainly metabolized by APA in the myocardium while ACE2 is the main enzyme responsible for Ang-(1-7) formation from Ang II in the LV. This is the first report on localization of Ang II processing enzymes in the heart using MALDI imaging. This procedure can be exploited for the development of new therapeutic avenues that can be used to target the devastating Ang II effects within the myocardium.
Abstract 381: Upregulation of Tumor Necrosis Factor α-converting Enzyme (TACE) Protein Expression in db/db Mice is Reversed by Rosiglitazone
Authors: Chodavarapu Harshita , Somineni Hari K , Salem Esam , Morris Mariana , Elased Khalid M
Published: July 2021

TACE, also known as ADAM17, is involved in the ectodomain shedding of several membrane bound proteins. Angiotensin converting enzyme 2 (ACE2), homologue of angiotensin converting enzyme (ACE), is known to be renoprotective by increasing the degradation of vasoactive peptide Angiotensin II (Ang II) to vasodilator peptide Ang - (1-7). It has been shown before that TACE mediates regulated ectodomain shedding of ACE2. PPARγ agonist, rosiglitazone, is known to impart renoprotection by attenuating albuminuria. However, the exact mechanism of renoprotection is not clear. Our previous results and others showed that renal ACE2 protein expression is increased during early stages of diabetes in db/db mice. We also demonstrated increased urinary ACE2 excretion in db/db mice. The goal of this study is to test the hypothesis that TACE is upregulated in db/db diabetic mice and treatment with rosiglitazone imparts renoprotection by attenuating the shedding of renal ACE2 via downregulating TACE protein expression. Male 6 week db/db mice were fed rosiglitazone (20mg/kg/day) for 10 weeks. Metabolic and urinary parameters were monitored weekly. Kidney lysate and urine was used to perform western blot and ACE2 activity (pmols/h/μg protein) respectively. db/db mice demonstrated glucose intolerance, hyperglycemia (348.2±29.9 mg/dL), and albuminuria (0.3±0.05 mg/day) at a very early age. Chronic rosiglitazone treatment normalized blood glucose levels (142.0±12.2 mg/dL), improved glucose tolerance and decreased albuminuria (0.17±0.03 mg/day) in treated db/db mice. Western blot showed increased renal TACE protein expression of db/db mice compared to controls (p<0.05). Treatment with rosiglitazone significantly decreased renal TACE protein expression in treated db/db mice compared to untreated mice (p<0.05). In addition, db/db mice demonstrated a 7 fold increase in urinary ACE2 activity (15.1±4.5) compared to controls (1.74±0.9). Treatment with rosiglitazone significantly attenuated and normalized ACE2 activity in treated db/db mice (0.1±0.06). In conclusion, TACE is upregulated in db/db mice and normalizing hyperglycemia with rosiglitazone could impart renoprotection by decreasing renal TACE protein expression and shedding of renal ACE2.
Abstract 386: Compound 21 Induces Natriuresis via Renal AT2 Receptor Activation in Male and Female Rats
Authors: Kemp Brandon A , Howell Nancy L , Carey Robert M
Published: July 2021

Endogenous renal des-aspartyl
1
-angiotensin II (angiotensin III) activates renal proximal tubule AT
2
receptors (AT
2
Rs) and induces natriuresis via a nitric oxide-cyclic GMP signaling pathway. The present study explores the ability of highly selective non-peptide AT
2
R agonist Compound 21 (C21) to induce natriuresis. Sprague-Dawley rats (12 weeks old; male N=22; female N=18) were studied in the presence and absence of concurrent 24-h AT
1
R blockade with candesartan (CAND;0.01 mg/kg/min). Rats were anesthetized with Inactin 100 mg/kg i.p., uninephrectomized and instrumented for delivery of 3 cumulative 30-min i.v. infusions of C21 (100, 200, and 300 ng/kg/min) following a 30-min control infusion of vehicle. Mean arterial pressure (MAP) was measured for all periods and urine Na
+
excretion rate (U
Na
V) was calculated for the control and final C21 collection periods. To determine whether the systemically induced natriuresis is mediated by renal AT
2
Rs, PD-123319 (PD), a specific AT
2
R antagonist, was infused directly into the renal cortical interstitium(20 μg/kg/min and 10 μg/kg/min for females and males, respectively) during the i.v. C21 infusions. In female rats, C21 increased U
Na
V from 1.5 ± 0.20 to 7.48 ± 0.95 μmol/min (P<0.0001). This response was abrogated by concurrent intrarenal PD infusion [control 0.74 ± 0.19 vs. C21 2.02 ± 0.50 μmol/min (P<0.001from C21 alone). Systemic CAND administration augmented the natriuretic response to C21 [control 1.29 ± 0.25 vs. C21 10.68 ± 0.70 μmol/min (P<0.05 from C21 alone)]. In male rats, C21 increased U
Na
V from 0.46 ±0.08 to 6.21 ± 1.33 μmol/min (P<0.01). This response was blocked by concurrent intrarenal PD infusion [control 0.39 ± 0.11 vs. C21 1.69 ± 0.53 μmol/min (P<0.05 from C21 alone). Systemic CAND did not significantly alter the natriuretic response to C21 alone [control 0.49 ± 0.15 vs. C21 7.67 ± 0.72 μmol/min (P = NS from C21 alone). In female rats, CAND augmented the natriuretic response to C21 over that of male rats (P<0.01). Systemic arterial pressures were decreased by CAND in both male and female rats but were unchanged by C21 alone or together with intrarenal PD. C21 induces natriuresis via renal AT
2
R activation in both male and female rats. These data suggest the potential for AT
2
R agonist therapy in hypertension.