Soluble Guanylate Cyclase-Mediated Relaxation in Aortas from Rats with Renovascular Hypertension

Soluble guanylate cyclase (sGC) plays an important role in nitric oxide (NO)-mediated regulation of vascular tone; however, NO bioavailability is often reduced in diseased blood vessels. Accumulating evidence suggests that a shift of sGC from the NO-sensitive form to the NO-insensitive form could be an underlying cause contributing to this reduction. Herein, we investigated the impact of renovascular hypertension on NO-sensitive and NO-insensitive sGC-mediated relaxation in rat aortas. Renovascular hypertension was induced by partially clipping the left renal artery (2-kidneys, 1-clip; 2K1C) for 10 weeks. Systolic, diastolic, and mean arterial pressures were significantly increased in the 2K1C group when compared with the sham group. In addition, plasma thiobarbituric acid reactive substances and aortic superoxide generation were significantly enhanced in the 2K1C group when compared with those in the sham group. The vasorelaxant response of isolated aortas to the sGC stimulator BAY 41-2272 (NO-sensitive sGC agonist) was comparable between the sham and 2K1C groups. Likewise, the sGC activator BAY 60-2770 (NO-insensitive sGC agonist)-induced relaxation did not differ between the sham and 2K1C groups. In addition, the cGMP mimetic 8-Br-cGMP (protein kinase G agonist) induced similar relaxation in both groups. Furthermore, there were no differences in BAY 41-2272-stimulated and BAY 60-2770-stimulated cGMP generation between the groups. These findings suggest that the balance between NO-sensitive and NO-insensitive forms of sGC is maintained during renovascular hypertension. Therefore, sGC might not be responsible for the reduced NO bioavailability observed during renovascular hypertension.

CLINICAL CASE OF ARTERIAL HYPERTENSION IN A NEWBORN

Aim. To use personal clinical experience in monitoring and treating a newborn with persistent arterial hypertension (AH) due to left renal artery stenosis to demonstrate the current state of this problem in the context of limited experience of work with such rare pathologies in children.Materials and methods. The research was based on the examination and treatment of a newborn with persistent AH due to left renal artery stenosis. The complex of diagnostic procedures included: clinical and laboratory examinations, X-ray examination methods (with the use of contrast agents), magnetic resonance imaging, ultrasound examination and Dopplerography, and histological examination of surgical material.Results. Conservative treatment of the patient's AH with the use of antihypertensive agents did not achieve desired results.Taking into account possible etiologic and pathogenetic factors of AH in newborns, Doppler examination was performed to exclude congenital heart defects (coarctation of the aorta). Pathology was excluded.Cortisol and 17-OH progesterone levels were determined to exclude suprarenal pathology and showed the following: cortisol level was 173.9% higher than the maximum permissible level; 17-OH progesterone level was 9.9% higher than the norm.Considering the presence of neurological symptoms, an MRI of the brain with angiography was performed. No pathology was detected.Due to the presence of persistent arterial hypertension, which did not respond to medication, a CT with contrast was ordered, during which were revealed CT-signs of critically small diameter of the left renal artery (probable dissection) with pronounced cystic and ischemic changes of the lateral half of the left kidney without excretory function at 15 min. The main treatment measures included the following: adequate preoperative preparation, anesthetic support and the selection of an adequate and effective operative method to eliminate the pathology. The only available method of surgical intervention was nephrectomy - removal of the left kidney.Analyzing the results of the investigation, it can be stated that nephrectomy is the pathogenetic method of treatment of this pathology. Steady stabilization of arterial blood pressure was achieved within 1 hour after the operation.Conclusions. 1. When persistent AH is detected in a newborn, the presence of organic pathology should be excluded. 2. If the patient has organic pathology that causes a persistent increase in arterial blood pressure, the root cause of the pathology should be eliminated if possible. 3. Conservative treatment of persistent AH in children caused by renovascular or renal factors does not provide significant results and is not appropriate. 4. Nephrectomy is the pathogenetic method of treating AHT in a newborn with renal artery stenosis.

Refractory hypertension secondary to renal artery stenosis with a honeycomb-like structure

Background A honeycomb-like structure (HLS) is a rare abnormality characterized by a braid-like appearance. Angiograph and intravascular examination, including coherence tomography and intravascular ultrasound (IVUS), can further confirm the multiple intraluminal channels or honeycomb structure, which can also be described as looking like ‘swiss cheese’, a ‘spider web’ or a ‘lotus root’. Previous studies have mostly reported this abnormality in coronary arteries, with a few cases in renal arteries. More information about the characteristics and development of HLS is needed. Case presentation A 69-year-old Han man with resistant hypertension received abdominal enhanced computerised tomography and was revealed to have left renal artery stenosis with the possibility of left renal infarction. Renal artery angiography confirmed a 95% stenosis located in the proximal segment of the left renal artery, and the middle segment was blurred with multi-channel-like blood flow. Further IVUS was performed and identified multiple channels surrounded by fibrous tissue. It was a rare case of HLS in the renal artery secondary to the thrombus, with organisation and recanalisation. Balloon dilatation and stent implantation at the proximal segment of the left renal artery were performed successfully. Blood pressure was well controlled after the procedure. Conclusions The IVUS findings are helpful for forming interventional therapeutic strategies for HLS lesions in the renal artery.

Physician-Modified Endograft With Inner Branches for the Treatment of Complex Aortic Urgencies

Purpose To describe the use of physician-modified endograft (PMEG) with the exclusive use of inner branches or in combination with fenestrations for the urgent treatment of complex aortic aneurysms. Technique We present two urgent cases. A patient with a 6.8 cm saccular juxtarenal aneurysm and another patient with a contained rupture of the thoracoabdominal aorta right above the celiac trunk (CT). In both cases, a Cook Zenith TX2 thoracic endograft was back-table modified, in the first case by adding three fenestrations and one inner branch for the left renal artery to improve sealing due to its partial involvement in the aneurysm and, in the second case, with the use of two inner branches for the CT and superior mesenteric artery. Both procedures were successful, with uneventful postoperative courses and complete aneurysm exclusion on postoperative CT angiography. Conclusion Use of PMEGs with inner branches is feasible for urgent repair in complex aortic anatomy.

Curcumin Protects against Renal Ischemia/Reperfusion Injury by Regulating Oxidative Stress and Inflammatory Response

Objective. The aim of this study was to explore the pharmacological effects of curcumin on oxidative stress and inflammatory response of renal dysfunction induced by renal ischemia/reperfusion (RIRI). Methods. Fifty male SD rats (Sprague Dawley) were randomly divided into the sham group, RIRI group, and curcumin group (low, medium, and high). The RIRI model was established by clipping the left renal artery for 45 min and then reperfusion for 24 h and resection of the contralateral kidney. In the curcumin group, curcumin was intraperitoneally injected once a day for 3 consecutive days using different dosage regimens. The RIRI group was intraperitoneally administered with normal saline. Renal injury was evaluated by measuring the concentration of creatinine (Cr) and urea nitrogen (BUN) in serum. Oxidative stress was assessed by assessing the level of malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione (GSH), and iron reduction/antioxidant capacity (FRAP) in tissues. In addition, the protective effect of RIRI was investigated by measuring Paller scores, the level of serum inflammatory factors and caspase-3, and the number of apoptotic cells. Results. Ischemia/reperfusion resulted in increased levels of Cr and BUN in serum and MDA in tissues and decreased levels of SOD, CAT, GPx, GSH, and FRAP. Curcumin pretreatment strikingly increased the level of SOD, CAT, GPx, GSH, IL-10, IFN-γ, and FRAP and significantly decreased MDA, Cr, BUN, IL-8, TNF-α, IL-6, and myeloperoxidase (MPO) expressions in tissues. Conclusion. Curcumin can relieve the degree of renal injury and improve renal function in ischemia-reperfusion, which may be related to the fact that curcumin can increase SOD content in serum and reduce MDA and FRAP levels in the rat model.

Successful endovascular treatment for acute renal artery occlusion

Purpose: We report a case of revascularization for a totally occluded renal artery using endovascular renal thrombus aspiration followed by catheter-directed thrombolysis.Case Report: A 56 years old man presented with sudden onset of severe left-sided abdominal and loin pain for six hours. Urgent computed tomography angiogram showed total occlusion of left renal artery. Emergency selective left renal angiogram and thrombus aspiration using a 5-French Cobra catheter was performed. Catheter-directed thrombolysis with urokinase was initiated after aspiration thrombectomy. Angiogram 24 hours after thrombolysis showed the left renal artery and its segmental branches were successfully revascularized. Patient was on anticoagulation after operation and his renal function recovered well.Conclusion: Percutaneous aspiration thrombectomy combined with intra-arterial local fibrinolysis are effective in the salvage of renal function.

In Vivo and In Vitro Evaluation of Urinary Biomarkers in Ischemia/Reperfusion-Induced Kidney Injury

Oxidative stress plays an important role in the pathophysiology of acute kidney injury (AKI). Previously, we reported that vanin-1, which is involved in oxidative stress, is associated with renal tubular injury. This study was aimed to determine whether urinary vanin-1 is a biomarker for the early diagnosis of AKI in two experimental models: in vivo and in vitro. In a rat model of AKI, ischemic AKI was induced in uninephrectomized rats by clamping the left renal artery for 45 min and then reperfusing the kidney. On Day 1 after renal ischemia/reperfusion (I/R), serum creatinine (SCr) in I/R rats was higher than in sham-operated rats, but this did not reach significance. Urinary N-acetyl-β-D-glucosaminidase (NAG) exhibited a significant increase but decreased on Day 2 in I/R rats. In contrast, urinary vanin-1 significantly increased on Day 1 and remained at a significant high level on Day 2 in I/R rats. Renal vanin-1 protein decreased on Days 1 and 3. In line with these findings, immunofluorescence staining demonstrated that vanin-1 was attenuated in the renal proximal tubules of I/R rats. Our in vitro results confirmed that the supernatant from HK-2 cells under hypoxia/reoxygenation included significantly higher levels of vanin-1 as well as KIM-1 and NGAL. In conclusion, our results suggest that urinary vanin-1 might be a potential novel biomarker of AKI induced by I/R.

Hydrogen Sulphide Treatment Prevents Renal Ischemia-Reperfusion Injury by Inhibiting the Expression of ICAM-1 and NF-kB Concentration in Normotensive and Hypertensive Rats

Our main objective was to investigate the effect of chronic administration of hydrogen sulphide donor (sodium hydrosulphide) on the expression of intercellular adhesion molecule-1 (ICAM-1) and concentration of nuclear factor-kappa B (NF-kB) in a renal ischemia-reperfusion injury (IRI) model of WKY and L-nitro-arginine-methyl-ester (L-NAME)-induced hypertensive rats. Sodium hydrosulphide (NaHS) was administered intraperitoneally (i.p.) for 35 days while cystathionine gamma lyase (CSE) inhibitor dL-propargylglycine (PAG) was administered at a single dose of 50 mg/kg. Animals were anesthetised using sodium pentobarbitone (60 mg/kg) and then prepared to induce renal ischemia by clamping the left renal artery for 30 min followed by 3 h of reperfusion. Pre-treatment with NaHS improved the renal functional parameters in both WKY and L-NAME-induced hypertensive rats along with reduction of blood pressure in hypertensive groups. Oxidative stress markers like malondialdehyde (MDA), total superoxide dismutase (T-SOD) and glutathione (GSH) were also improved by NaHS treatment following renal IRI. Levels of ICAM-1 and NF-kB concentration were reduced by chronic treatment with NaHS and increased by PAG administration after renal IRI in plasma and kidney. Treatment with NaHS improved tubular morphology and glomerulus hypertrophy. Pre-treatment with NaHS reduced the degree of renal IRI by potentiating its antioxidant and anti-inflammatory mechanism, as evidenced by decreased NF-kB concentration and downregulation of ICAM-1 expression.

Patient with Nutcracker Syndrome Treated by Spiral Vein Graft Bypass

Nutcracker syndrome is a vascular pathology result from compressing the left renal vein between the superior mesenteric artery (SMA) and abdominal aorta. Patients usually complain of abdominal pain and symptoms from renal venous hypertension. In this case, a 32-year-old male patient presented with chronic abdominal pain for two years. İnvestigations showed the left renal artery compressed between SMA and abdominal aorta. He was operated on by using a spiral saphenous vein graft. The operation was done successfully with no complications.