Abstract 71: Novel Bach1 Modulators Increase HMOX1 and Suppress Hypertension in the Goldblatt Model of Renovascular Hypertension

Hypertension ◽  
2013 ◽  
Vol 62 (suppl_1) ◽  
Author(s):  
Matthew Kostura ◽  
Otis Attucks ◽  
Jareer Kassis ◽  
Suparna Gupta ◽  
Samuel Victory ◽  
...  

We report for the first time a novel class of compounds that specifically modulate the Bach1 transcriptional repressor pathway. In cellula, the compounds selectively inhibit the activity of the transcriptional repressor Bach1 resulting in transcription of a network of antioxidant and cytoprotective genes including HMOX1. HPP-1971, a member of this class, is a potent and selective Bach1 inhibitor that induces HMOX1 > 40-fold with a potency of 408 nM in human lung fibroblasts. To assess activity in vivo, we tested HPP-1971 in the Goldblatt model of renovascular hypertension. Sprague Dawley rats were implanted with in dwelling pressure telemeter probes and subsequently underwent sham surgery or placement of a 0.25 mm silver clip around the left renal artery. HPP-1971 treatment, dosed orally at 1,3,10 and 30 mpk, commenced three days following clip surgery, and continued for 18 days. At study completion, blood pressure, clipped kidney weight, renal HMOX1 enzyme activity and plasma aldosterone levels were measured (see Table). HPP-1971 attenuated both kidney atrophy and the increase in blood pressure in a dose dependent manner with significant differences seen at 3, 10 and 30 mpk (p<.0001). HMOX1 enzyme activity in the clipped kidney increased with treatment, reaching a maximum of 5.7 ± 0.9 nM/hr/mg at 30 mpk relative to sham operated animals (p<.0001). Plasma aldosterone levels increased in 2K1C animals compared to sham controls but were reduced by HPP-1971 treatment. These findings define a novel role for Bach1 suppressors in counteracting the influence of the RAAS system on hypertension and kidney atrophy in the 2K1C model of renovascular hypertension.

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Mi Hyeon Hong ◽  
Hye Yoom Kim ◽  
Youn Jae Jang ◽  
Se Won Na ◽  
Byung Hyuk Han ◽  
...  

In this study, we evaluated the effect of a traditional herbal formula, Ma Huang Tang (MHT), on blood pressure and vasodilation in a rat model of NG‐nitro‐L‐arginine methylester- (L-NAME-) induced hypertension. We found that MHT-induced vascular relaxation in a dose-dependent manner in rat aortas pretreated with phenylephrine. However, pretreatment of endothelium-intact aortic rings with L‐NAME, an inhibitor of nitric oxide synthesis (NOS), or 1H‐[1, 2, 4]‐oxadiazole‐[4, 3‐α]‐quinoxalin‐1‐one (ODQ), an inhibitor of soluble guanylyl cyclase, significantly abolished vascular relaxation induced by MHT. MHT also increased the production of guanosine 3′,5′-cyclic monophosphate (cGMP) in the aortic rings pretreated with L-NAME or ODQ. To examine the in vivo effects of MHT, Sprague Dawley rats were treated with 40 mg/kg/day L-NAME for 3 weeks, followed by administration of 50 or 100 mg/kg/day MHT for 2 weeks. MHT was found to significantly normalize systolic blood pressure and decreased intima-media thickness in aortic sections of rats treated with L-NAME compared to that of rats treated with L-NAME alone. MHT also restored the L-NAME-induced decrease in vasorelaxation response to acetylcholine and endothelial nitric oxide synthase (eNOS) and endothelin-1 (ET-1) expression. Furthermore, MHT promoted the recovery of renal function, as indicated by osmolality, blood urea nitrogen (BUN) levels, and creatinine clearance. These results suggest that MHT-induced relaxation in the thoracic aorta is associated with activation of the nitric oxide/cGMP pathway. Furthermore, it provides new therapeutic insights into the regulation of blood pressure and renal function in hypertensive patients.


Hypertension ◽  
2015 ◽  
Vol 66 (suppl_1) ◽  
Author(s):  
Syed Siraj Ahmed Quadri ◽  
Caixia Li ◽  
Silas Culver ◽  
Helmy M Siragy

We hypothesized that PRR plays a role in renal inflammation in 2-kidney, 1-clip (2K1C) hypertension rat model. Male Sprague-Dawley rats were fed normal sodium diet. BP was obtained before and 28 days after left renal artery clipping. Renal expressions of PRR, TNF-α and COX-2 were assessed in sham and 2K1C rats with or without left renal interstitial administration of scramble shRNA or PRR shRNA. At baseline there were no significant differences in BP between different animal groups. Compared to sham, mean arterial blood pressure significantly increased in 2K1C (2K1C 131.8 ± 3.09 mmHg, vs. sham 108 ± 1.9 mmHg, P<0.0.05) at day 28 and was not influenced by scramble shRNA or PRR shRNA treatment. Compared to sham and contra lateral (non-clipped) kidney, there were increases in mRNA and protein expressions of PRR (90% and 45%, P<0.01), TNF-α (72% and 50%, P<0.05), COX-2 (72% and 39%, P<0.05) in the clipped kidney. These expressions were not influenced by scramble shRNA treatment. Compared to 2K1C (no treatment) and scramble shRNA, PRR shRNA treatment in the clipped kidney caused significant reductions in mRNA and protein expressions of PRR (60% and 54%, P<0.01, shown in figure below), TNF-α (54% and 51%, P<0.05), COX-2 (51% and 53%, P<0.05). We conclude that PRR mediates renal inflammation in renovascular hypertension independent of blood pressure reduction.


2007 ◽  
Vol 293 (2) ◽  
pp. G493-G500 ◽  
Author(s):  
Eddy Viard ◽  
Zhongling Zheng ◽  
Shuxia Wan ◽  
R. Alberto Travagli

Cholecystokinin (CCK) has been proposed to act in a vagally dependent manner to increase pancreatic exocrine secretion via actions exclusively at peripheral vagal afferent fibers. Recent evidence, however, suggests the CCK-8s may also affect brain stem structures directly. We used an in vivo preparation with the aims of 1) investigating whether the actions of intraduodenal casein perfusion to increase pancreatic protein secretion also involved direct actions of CCK at the level of the brain stem and, if so, 2) determining whether, in the absence of vagal afferent inputs, CCK-8s applied to the dorsal vagal complex (DVC) can also modulate pancreatic exocrine secretion (PES). Sprague-Dawley rats (250–400 g) were anesthetized and the common bile-pancreatic duct was cannulated to collect PES. Both vagal deafferentation and pretreatment with the CCK-A antagonist lorglumide on the floor of the fourth ventricle decreased the casein-induced increase in PES output. CCK-8s microinjection (450 pmol) in the DVC significantly increased PES; the increase was larger when CCK-8s was injected in the left side of the DVC. Protein secretion returned to baseline levels within 30 min. Microinjection of CCK-8s increased PES (although to a lower extent) also in rats that underwent complete vagal deafferentation. These data indicate that, as well as activating peripheral vagal afferents, CCK-8s increases pancreatic exocrine secretion via an action in the DVC. Our data suggest that the CCK-8s-induced increases in PES are due mainly to a paracrine effect of CCK; however, a relevant portion of the effects of CCK is due also to an effect of the peptide on brain stem vagal circuits.


Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Saori Kitamura ◽  
Hiroko Hashimoto ◽  
Yukiko Segawa ◽  
Nobutaka Kurihara

Objective: Allium bakeri (AB) known as “rakkyo” and Allium sativum known as “garlic” contain alliin. Alliin easily turns into allicin, which is reported to decrease blood pressure (BP) through activating the excitatory ion channel transient receptor potential ankyrin-1. Thus, it is suggested that these vegetable decrease BP. Actually, garlic is reported to decrease BP and aortic media thickness in hypertensive animal models. However, it is practically difficult that garlic shows the effects, because it can hardly be eaten without heating and allicin is thermolabile. On the other hand, AB is usually eaten without heating. Therefore, in this study, we tested whether AB intake alleviates hypertension and aortic media thickness in hypertensive rats. Method: We used 2-kidney, 1-clip (2K1C) renovascular hypertension model. Male Sprague-Dawley rats (6 wo) were treated with sham operation (SHAM) or clipping the left renal artery (2K1C). After surgery, SHAM and 2K1C rats were respectively divided into 2 groups, which received a control diet (CONT) or a diet containing 1.0 % (w/w) freeze-dried AB powder for 7 weeks (AB). The systolic BP (SBP) was measured by a tail-cuff method every week. At the end of the protocol, mean arterial BP (MAP) was measured in each rat under anesthesia. Then, thoracic aorta was removed and the section of aorta was stained with hematoxylin and eosin. Results: From the 2nd week after surgery until the end of the protocol, SBP in 2K1C-CONT went up significantly compared with SHAM-CONT (174 ± 7 vs 120 ± 5 mmHg, at the end of the protocol, P < 0.01). However, SBP in 2K1C-AB did not go up through the protocol (127 ± 7 mmHg, P < 0.01 with 2K1C-CONT, at the end). In addition, the AB diet showed no significant effects on SBP in SHAM. These observations in SBP were similar to in MAP at the end of the protocol. The aortic media thickening was observed in 2K1C-CONT compared with SHAM-CONT. In 2K1C-AB, the thickness was significantly decreased compared with 2K1C-CONT, and was not significantly different from that in SHAM-AB. There were not significant differences between SHAM-CONT and SHAM-AB. Conclusion: Chronic intake of Allium bakeri, which can be eaten without heating, alleviated hypertension and aortic media thickness in rats with renovascular hypertension.


1990 ◽  
Vol 258 (2) ◽  
pp. F397-F402 ◽  
Author(s):  
T. Katoh ◽  
H. Chang ◽  
S. Uchida ◽  
T. Okuda ◽  
K. Kurokawa

In the present study, we tested the direct effects of endothelin (ET) on rat kidney in vivo. ET was infused into the left renal artery of anesthetized rats at a rate of 0.5, 5, 20, or 40 pmol/h. ET reduced ipsilateral urine volume (V), clearance of inulin (CIN), and clearance of p-aminohippuric acid (CPAH) in a dose-dependent manner. Thus ET at 20 pmol/h did not change V but decreased renal plasma flow (RPF) and glomerular filtration rate (GFR) by 27.6 +/- 14.3 and 30.8 +/- 10.4%, respectively, in the ipsilateral kidney. ET at 0.5 pmol/h was without effect and at 5 pmol/h had only minor effects on CIN and CPAH of ipsilateral kidney. At 40 pmol/h, ET reduced ipsilateral V, GFR, and RPF by 52.3 +/- 21.4, 58.4 +/- 14.5, and 72.5 +/- 10.6%, respectively. Filtration fraction and fractional excretion of Na remained unchanged during ET infusion. ET, 40 pmol/h, infused into the renal artery together with atrial natriuretic peptide (ANP) at a rate of 12 pmol/h reduced the ipsilateral V, GFR, and RPF by 33.2 +/- 6.3, 26.1 +/- 6.0, and 27.2 +/- 7.1%, respectively, decrements less than those with ET alone. When a calcium-channel blocker nicardipine was infused at a rate of 2.5 micrograms/h into the renal artery together with ET, 20 pmol/h, there was little change in the ipsilateral V, RPF, and GFR; ET, 40 pmol/h, with nicardipine did not change V and decreased GFR and RPF by 25.9 +/- 5.6 and 23.1 +/- 10.8%, respectively, decrements less than those without nicardipine.(ABSTRACT TRUNCATED AT 250 WORDS)


1997 ◽  
Vol 272 (6) ◽  
pp. R1698-R1703 ◽  
Author(s):  
M. A. Allen ◽  
P. M. Smith ◽  
A. V. Ferguson

Adrenomedullin (ADM) circulates in the blood at concentrations comparable to other vasoactive peptides with established roles in cardiovascular regulation. Intravenously administered ADM produces a clear hypotensive effect, whereas intracerebroventricular microinjections result in increases in blood pressure (BP). Recently, we demonstrated that ADM influences neurons of the area postrema (AP), a central nervous system site implicated in cardiovascular control. However, to address directly the physiological significance of the actions of ADM at the AP, an in vivo microinjection study was undertaken. ADM, at two concentrations (1 and 10 microM), in volumes of 50, 100, and 200 nl, was microinjected into the AP or NTS of 21 urethan-anesthetized male Sprague-Dawley rats. Microinjection of 10 microM ADM (100 nl) resulted in significant transient (2-5 min) increases in BP [120 s area under the curve (AUC): 684.3 +/- 268.6 mmHg/s (P < 0.05)], and heart rate (HR) [AUC: 12.5 +/- 4.5 beats/min (P < 0.05)]. The lower concentration of ADM (1 microM) had no effect on either BP (179.1 +/- 143.6 mmHg/s) or HR (0.8 +/- 2.6 beats/min). ADM was also microinjected into the immediately adjacent nucleus of the solitary tract, where it was found to be without effect on either BP or HR. This study demonstrates, for the first time, a physiological role for ADM acting at a specific brain site, the AP, to produce significant cardiovascular responses.


1998 ◽  
Vol 275 (5) ◽  
pp. H1826-H1833 ◽  
Author(s):  
L. G. Melo ◽  
A. T. Veress ◽  
U. Ackermann ◽  
H. Sonnenberg

Atrial natriuretic peptide (ANP) exerts a chronic hypotensive effect due to a decrease in total peripheral resistance (TPR). This study examines if chronic ANP-dependent vasodilation is attributable to differences in the cardiovascular regulatory activity of vascular endothelium (VE), based on evidence that ANP affects synthesis/release and target cardiovascular effects of endothelin-1 (ET-1), C-type natriuretic peptide (CNP), and nitric oxide (NO). To determine if the synthetic activity of resistance vasculature VE is chronically altered by plasma ANP activity, we measured ET-1, CNP, and endothelial constitutive NO synthase (ecNOS) concentration and total NOS enzyme activity in homogenates of kidney, heart, lung, hindquarter skeletal muscle, and brain from hypotensive transgenic mice with elevated plasma ANP, hypertensive knockout mice (−/−) characterized by the absence of ANP, and the corresponding normotensive wild-type (NT, +/+) mice. Tissue distribution and abundance patterns of ET-1, CNP, ecNOS, and NOS enzyme activity were comparable between the different genotypes and did not differ significantly between mutant and control mice. Antagonism of ETA/B receptors in −/− and +/+ mice in vivo with SB-209670 reduced arterial blood pressure (ABP) significantly and comparably in both genotypes (−27 ± 4 and −25 ± 2% change for −/− and +/+ mice, respectively) independent of any significant changes in heart rate (HR) (−6 ± 8 and −4 ± 4% change for −/− and +/+ mice, respectively). Immunoneutralization of CNP-specific guanylate cyclase-linked receptors (GC-B) with monoclonal antibodies (3G12) increased ABP slightly, but not significantly, by similar relative amounts in both −/− (10 ± 6% change) and +/+ mice (8 ± 3% change), without changing HR significantly (4 ± 1% change for both +/+ and −/− mice). Inhibition of NOS activity (by N G-nitro-l-arginine methyl ester) significantly increased ABP, but the changes were comparable between −/− (53 ± 5% change) and +/+ mice (50 ± 6% change) and occurred in the absence of significant changes in HR (−1 ± 5 and 7 ± 5% change for −/− and +/+ mice, respectively). We conclude that the differences in ABP associated with chronic variations in endogenous ANP activity are not due to alterations in synthesis or responsiveness of the cardiovascular system to the effects of ET-1, CNP, or NO.


1988 ◽  
Vol 255 (6) ◽  
pp. E839-E842
Author(s):  
M. Chen ◽  
J. G. Lee ◽  
R. L. Malvin ◽  
B. S. Huang

The present experiments were designed to determine if an opiate antagonist affects blood pressure in two-kidney one-clip Goldblatt rats. Male Sprague-Dawley rats were divided into three groups. Group 1 received an infusion of saline intraperitoneally via an osmotic pump and left renal artery constriction (RAC). In group 2, rats were treated the same as group 1, except that they received an intraperitoneal infusion of naloxone (100 micrograms/h). Group 3 received the same infusion of naloxone without RAC. Naloxone-infused Goldblatt rats showed a significantly lower systolic blood pressure (SBP) than saline-infused Goldblatt rats (132 +/- 7 vs. 160 +/- 9 mmHg at day 14), but a higher SBP than control (132 +/- 7 vs. 106 +/- 1 mmHg). Infusion of naloxone did not significantly change SBP in normotensive rats. Renal renin activity in the clipped kidney was higher than in the nonclipped kidney in groups 1 and 2. Plasma renin activity (PRA) in both groups of Goldblatt rats was higher than in group 3, but no significant difference was found between the two groups of Goldblatt rats (groups 1 and 2). Naloxone (1.5 microM) did not affect the basal secretion of renin by isolated cortical slices from untreated rats. The present data demonstrate that naloxone significantly attenuates the development of hypertension in two-kidney one-clip rats. The attenuation of blood pressure was not associated with the changes in PRA, renal renin activity, or plasma aldosterone concentrations. The data support the hypothesis that the endogenous opioid system may be involved in the development of renovascular hypertension.


2019 ◽  
Vol 10 (11) ◽  
Author(s):  
Ying Yang ◽  
Nandan Wu ◽  
Yihui Wu ◽  
Haoting Chen ◽  
Jin Qiu ◽  
...  

Abstract Retinoblastoma (RB) is the most common primary intraocular malignancy in children. Intravitreal chemotherapy achieves favorable clinical outcomes in controlling RB vitreous seeds, which are a common reason for treatment failure. Thus, a novel, effective and safe intravitreal chemotherapeutic drug is urgently required. The malaria drug artesunate (ART) recently demonstrated remarkable anticancer effects with mild side effects. The purpose of this study is to investigate the anti-RB efficacy, the underlying mechanism and the intraocular safety of ART. Herein, we verified that ART inhibits RB cell viability and induces cell apoptosis in a dose- and time-dependent manner. Microarray analysis revealed that Kruppel-like factor 6 (KLF6) was upregulated after ART treatment, and this was further confirmed by real-time PCR and western blot assays. Silencing of KLF6 expression significantly reversed ART-induced RB cell growth inhibition and apoptosis. Furthermore, ART activated mitochondria-mediated apoptosis of RB cells, while silencing KLF6 expression significantly inhibited this effect. In murine xenotransplantation models of RB, we further confirmed that ART inhibits RB tumor growth, induces tumor cell apoptosis and upregulates KLF6 expression. In addition, KLF6 silencing attenuates ART-mediated inhibition of tumor growth in vivo. Furthermore, we proved that intravitreal injection of ART in Sprague-Dawley (SD) rats is safe, with no obvious retinal function damage or structural disorders observed by electrophysiology (ERG), fundal photographs, fundus fluorescein angiography (FFA) or optical coherence tomography (OCT) examinations. Collectively, our study revealed that ART induces mitochondrial apoptosis of RB cells via upregulating KLF6, and our results may extend the application of ART to the clinic as an effective and safe intravitreal chemotherapeutic drug to treat RB, especially RB with vitreous seeds.


2004 ◽  
Vol 287 (5) ◽  
pp. F1076-F1083 ◽  
Author(s):  
Jian Song ◽  
Xinqun Hu ◽  
Osman Khan ◽  
Ying Tian ◽  
Joseph G. Verbalis ◽  
...  

The syndrome of inappropriate antidiuretic hormone (SIADH) is associated with water retention and hyponatremia. The kidney adapts via a transient natriuresis and persistent diuresis, i.e., vasopressin escape. Previously, we showed an increase in the whole kidney abundance of aldosterone-sensitive proteins, the α- and γ (70-kDa-band)-subunits of the epithelial Na+ channel (ENaC), and the thiazide-sensitive Na-Cl cotransporter (NCC) in our rat model of SIADH. Here we examine mean arterial pressure via radiotelemetry, aldosterone activity, and cortical vs. medullary ENaC subunit and 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD-2) protein abundances in escape. Eighteen male Sprague-Dawley rats (300 g) were sham operated ( n = 6) or infused with desmopressin (dDAVP; n = 12, a V2 receptor-selective analog of AVP). After 4 days, one-half of the rats receiving dDAVP were switched to a liquid diet, i.e., water loaded (WL) for 5–7 additional days. The WL rats had a sustained increase in urine volume and blood pressure (122 vs. 104 mmHg, P < 0.03, at 7 days). Urine and plasma aldosterone levels were increased in the WL group to 844 and 1,658% of the dDAVP group, respectively. NCC and α- and γ-ENaC (70-kDa band) were increased significantly in the WL group (relative to dDAVP), only in the cortex. β- and γ-ENaC (85-kDa band) were increased significantly by dDAVP in cortex and medulla relative to control. 11β-HSD-2 was increased by dDAVP in the cortex and not significantly affected by water loading. These changes may serve to attenuate Na+ losses and ameliorate hyponatremia in vasopressin escape.


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