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Abstract Background The oral gonadotropin-releasing hormone antagonist relugolix, which temporarily stops menstruation, is used to treat heavy menstrual bleeding, pelvic pressure, and low back pain in women with uterine fibroids. Treatment can also help women recover from low hemoglobin levels and possibly shrink the fibroids. However, evidence of preoperative use of relugolix before laparoscopic myomectomy is limited. Nevertheless, the treatment could reduce interoperative blood loss, decrease the risk of developing postoperative anemia, and shorten the operative time. Thus, we aim to test whether 12-week preoperative treatment with relugolix (40 mg orally, once daily) is similar to or not worse than leuprorelin (one injection every 4 weeks) to reduce intraoperative blood loss. Methods Efficacy and safety of preoperative administration of drugs will be studied in a multi-center, randomized, open-label, parallel-group, noninferiority trial enrolling premenopausal women ≥ 20 years of age, diagnosed with uterine fibroids and scheduled for laparoscopic myomectomy. Participants (n = 80) will be recruited in the clinical setting of participating institutions. The minimization method (predefined factors: presence or absence of fibroids ≥ 9 cm and the International Federation of Gynecology and Obstetrics [FIGO] type 1–5 fibroids) with randomization is used in a 1:1 allocation. Relugolix is a 40-mg oral tablet taken once a day before a meal, for 12 weeks, up to the day before surgery. Leuprorelin is a 1.88 mg, or 3.75 mg subcutaneous injection, given in three 4-week intervals during patient visits before the surgery. For the primary outcome measure of intraoperative bleeding, the blood flow is collected from the body cavity, surgical sponges, and collection bag and measured in milliliters. Secondary outcome measures are hemoglobin levels, myoma size, other surgical outcomes, and quality-of-life questionnaire responses (Kupperman Konenki Shogai Index and Uterine Fibroid Symptoms—Quality of Life). Discussion Real-world evidence will be collected in a clinical setting to use pre-treatment with an oral gonadotropin-releasing hormone antagonist to reduce intraoperative bleeding in women who undergo laparoscopic myomectomy. Trial registration jRCTs031210564 was registered on 19 January 2022 in the Japan Registry of Clinical Trials ( https://jrct.niph.go.jp ).

We aimed to examine the effects of a sodium glucose co-transporter 2 (SGLT2) inhibitor on systemic and intrarenal renin–angiotensin system (RAS) in subtotally nephrectomized non-diabetic rats, a model of chronic kidney disease (CKD). Oral administration of the selective SGLT2 inhibitor, TA-1887 (10 mg/kg/day), for 10 weeks induced glycosuria. However, plasma renin activity, plasma angiotensinogen levels, kidney angiotensin II contents and renal injury were not significantly affected by TA-1887. These data indicate that chronic treatment with an SGLT2 inhibitor does not activate the systemic and intrarenal RAS in subjects with non-diabetic CKD. Keywords: SGLT2 inhibitor, Renin–angiotensin system (RAS), Chronic kidney disease (CKD)

Background/Aims: Angiotensin receptor blockers (ARBs) may be beneficial for clinical remission during conventional therapy with tonsillectomy and steroid pulse (TSP) for active IgA nephropathy. Methods: Seventy-seven patients with active IgA nephropathy were randomly assigned to the control arm with conventional regimen (TSP followed by oral prednisolone) (n = 37) or the ARB arm with conventional regimen plus ARB candesartan for the first 6 months (n = 40). Patients not achieving proteinuria remission at 12 months in either arm were administered candesartan, which was titrated until the 24-month follow-up. The primary endpoints were remission of proteinuria (< 0.3 g/gCr) and hematuria at 12 months. Results: Baseline proteinuria (g/g Cr) were comparable between the control and ARB arm (1.02 vs. 0.97, P = 0.97). Similarly, cumulative remission rates at 6, 12, and 24 months were comparable between the control and ARB arms (37.8% vs. 35% [P = 0.80], 48.7% vs. 38.5% [P = 0.37], 71.4% vs. 51.3% [P = 0.08]). Proteinuria, which was slightly worse in the control arm than in the ARB arm at 6 months, was comparable afterwards (0.20 vs. 0.23 g/g Cr at 12 months; 0.12 vs. 0.13 g/g Cr at 24 months). Significant reductions observed in urinary angiotensinogen were almost comparable between the two treatment arms at both 6 and 12 months. Conclusion: Early candesartan treatment combined with TSP may not benefit clinical remission regardless of the blood pressure. ARB titration later during the treatment might provide benefit for patients with active IgA nephropathy.

High glucose has been demonstrated to induce angiotensinogen (AGT) synthesis in the renal proximal tubular cells (RPTCs) of rats, which may further activate the intrarenal renin-angiotensin system (RAS) and contribute to diabetic nephropathy. This study aimed to investigate the effects of high glucose on AGT in the RPTCs of human origin and identify the glucose-responsive transcriptional factor(s) that bind(s) to the DNA sequences of AGT promoter in human RPTCs. Human kidney (HK)-2 cells were treated with normal glucose (5.5 mM) and high glucose (15.0 mM), respectively. Levels of AGT mRNA and AGT secretion of HK-2 cells were measured by real-time polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. Consecutive 5'-end deletion mutant constructs and different site-directed mutagenesis products of human AGT promoter sequences were respectively transfected into HK-2 cells, followed by AGT promoter activity measurement through dual luciferase assay. High glucose significantly augmented the levels of AGT mRNA and AGT secretion of HK-2 cells, compared with normal glucose treatment. High glucose also significantly augmented AGT promoter activity in HK-2 cells transfected with the constructs of human AGT promoter sequences, compared with normal glucose treatment. Hepatocyte nuclear factor (HNF)-5 was found to be one of the glucose-responsive transcriptional factors of AGT in human RPTCs, since the mutation of its binding sites within AGT promoter sequences abolished the above effects of high glucose on AGT promoter activity as well as levels of AGT mRNA and its secretion. The present study has demonstrated, for the first time, that high glucose augments AGT in human RPTCs through HNF-5, which provides a potential therapeutic target for diabetic nephropathy.

The human gastrointestinal tract is inhabited by many types of microbiota, including bacteria, viruses, and fungi. Dysregulations of their microenvironment are associated with various health problems, not only limited to gastrointestinal disorders, such as inflammatory bowel disease, but to impacts beyond the intestine. For example, intestinal microbiota can affect the liver in non-alcoholic fatty liver disease, visceral adipose tissue during adipogenesis, and the heart in atherosclerosis. The factors contributing to these pathogeneses involve the gut microbiota and the effector organs of the host, and everything in between. The nuclear receptor peroxisome proliferator-activated receptors (PPARs) are pivotal for the modulation of many of the pathogeneses mentioned above. It is, therefore, conceivable that, in the process of host-microbiota interactions, PPARs play important roles. In this review, we focus on the interactions between host PPARs in different organs and gut microbiota and their impacts on maintaining health and various diseases.

Although recent studies have proven that renin-angiotensin system (RAS) blockades retard the progression of diabetic nephropathy, the detailed mechanisms of their reno-protective effects on the development of diabetic nephropathy remain uncertain. In rodent models, it has been reported that reactive oxygen species (ROS) are important for intrarenal angiotensinogen (AGT) augmentation in the progression of diabetic nephropathy. However, no direct evidence is available to demonstrate that AGT expression is enhanced in the kidneys of patients with diabetes. To examine whether the expression levels of ROS- and RAS-related factors in kidneys are increased with the progression of diabetic nephropathy, biopsied samples from 8 controls and 27 patients with type 2 diabetes were used. After the biopsy, these patients were diagnosed with minor glomerular abnormality or diabetes mellitus by clinical and pathological findings. The intensities of AGT, angiotensin II (Ang II), 4-hydroxy-2-nonenal (4-HNE), and heme oxygenase-1 (HO-1) were examined by fluorescence in situ hybridization and/or immunohistochemistry. Expression levels were greater in patients with diabetes than in control subjects. Moreover, the augmented intrarenal AGT mRNA expression paralleled renal dysfunction in patients with diabetes. These data suggest the importance of the activated oxidative stress/AGT/RAS axis in the pathogenesis of diabetic nephropathy.

A growing body of evidence suggests that podocyte apoptosis is a major cause of decreased podocyte number, which leads to albuminuria and glomerular injury. The aim of this study was to clarify the molecular mechanisms of angiotensin II (Ang II)-induced apoptosis in cultured mouse podocytes. We examined the effects of Ang II (100 nmol/L) on apoptosis, superoxide anions, and cytosol pH in podocytes. For intracellular pH measurements, image analysis was conducted using confocal laser microscopy after incubation with carboxyseminaphthorhodafluor-1. Superoxide anions and intracellular pH were elevated with Ang II treatment. Apoptotic cell numbers, as measured by TUNEL staining and caspase 3 activity, were also augmented in the Ang II–treated group. Pre-treatment with olmesartan (100 nmol/L, an Ang II type 1–receptor blocker), apocynin (50 μmol/L, NADPH oxidase inhibitor), or 5-N,N hexamethylene amiloride [30 μmol/L, Na+/H+ exchanger type 1 (NHE-1) inhibitor] abolished Ang II–induced podocyte apoptosis, whereas NHE-1 mRNA and protein expression was not affected by Ang II treatment. Moreover, Ang II increased NHE-1 phosphorylation. These results suggest that superoxide production, NHE-1 activation, and intracellular alkalization were early features prior to apoptosis in Ang II–treated mouse podocytes, and may offer new insights into the mechanisms responsible for Ang II–induced podocyte injury. Keywords:: angiotensin II, Na+/H+ exchanger type 1 (NHE-1), intracellular pH, apoptosis, podocyte

We examined the effects of angiotensin II AT1–receptor blockade with olmesartan on high fat (HF) diet–induced vascular oxidative stress and endothelial dysfunction in normal salt (NS) diet–fed Dahl salt-sensitive (DSS) rats. Treatment with NS + HF diet (32% crude fat, 0.3% NaCl) for 20 weeks significantly increased blood pressure in DSS rats. NS + HF diet–fed DSS rats also showed higher plasma levels of thiobarbituric acid–reactive substances, aortic superoxide production, and mRNA levels of p22phox and gp91phox in aortic tissues than NS diet–fed DSS rats. Furthermore, acetylcholine-induced vasorelaxation of aorta from NS + HF diet–fed DSS rats was significantly reduced. In NS + HF diet–fed DSS rats, treatment with olmesartan medoxomil (10 mg/kg per day, p.o.) and hydralazine (25 mg/kg per day, p.o.) similarly decreased blood pressure. However, in these animals, only olmesartan normalized plasma levels of thiobarbituric acid–reactive substances, vascular superoxide in aortic tissues, and acetylcholine-induced vasorelaxation. These data indicate that HF diet–induced hypertension is associated with vascular oxidative stress and endothelial dysfunction in NS diet–treated DSS rats. Inhibition of angiotensin II AT1 receptors may elicit beneficial effects on HF-induced hypertension and vascular injury in subjects that have genetically enhanced sodium-sensitive blood pressure. Keywords:: high fat (HF) diet, Dahl salt-sensitive (DSS) rat, oxidative stress, endothelial dysfunction, angiotensin II (AngII)

Angiotensin II (Ang II) infusion into rats elevates local angiotensin II levels through an AT1 receptor–dependent pathway in the kidney. We examined whether treatment with an angiotensin-converting enzyme (ACE) inhibitor, temocapril, or an AT1-receptor blocker, olmesartan, prevented elevation of Ang II levels in the kidney of angiotensin I (Ang I)-infused rats. Rats were infused with Ang I (100 ng/min) and treated with temocapril (30 mg/kg per day, n = 10) or olmesartan (10 mg/kg per day, n = 9) for 4 weeks. Ang I infusion significantly elevated blood pressure compared with vehicle-infused rats (n = 6). Treatment with temocapril or olmesartan suppressed Ang I–induced hypertension. Temocapril suppressed both plasma and renal ACE activity. Ang I infusion increased Ang II content in the kidney. Interestingly, temocapril failed to reduce the level of Ang II in the kidney, while olmesartan markedly suppressed an increase in renal Ang II levels. These results suggest a limitation of temocapril and a benefit of olmesartan to inhibit the renal renin–angiotensin system and suggest the possible existence of an ACE inhibitor– insensitive pathway that increases Ang II levels in rat kidney. Keywords:: angiotensin-converting enzyme (ACE) inhibitor, angiotensin II, kidney

In patients with diabetes, albuminuria is a risk marker of end-stage renal disease and cardiovascular events. An increased renin-angiotensin system activity has been reported to play an important role in the pathological processes in these conditions. We compared the effect of aliskiren, a direct renin inhibitor (DRI), with that of angiotensin receptor blockers (ARBs) on albuminuria and urinary excretion of angiotensinogen, a marker of intrarenal renin-angiotensin system activity.We randomly assigned 237 type 2 diabetic patients with high-normal albuminuria (10 to

The proximal tubule contains the highest expression of angiotensinogen mRNA and protein within the kidney and plays a vital role in the renal renin-angiotensin system. To study the regulation of angiotensinogen expression in the kidney in more detail, the proximal tubule needs to be accurately isolated from the rest of the nephron and separated into its three segments. The purpose of this study was to design a novel protocol using specific markers for the separation of proximal tubule cells into the three proximal tubule segments and to determine angiotensinogen expression in each segment. Kidneys were removed from C57BL/6J mice. The proximal tubules were aspirated from region of a Percoll gradient solution of the appropriate density. The proximal tubule was then separated into its three segments using segment-specific membrane proteins, after which each segment was characterized by a different specific marker (sodium-glucose transporter 2 for Segment 1; carbonic anhydrase IV for Segment 2; ecto-adenosine triphosphatase for Segment 3). The isolation of proximal tubules into three segments was successful, and angiotensinogen mRNA in Segment 2 and 3 and angiotensinogen protein in all three segments were confirmed. This protocol will be helpful for future studies of the detailed mechanisms of the intrarenal renin-angiotensin system.

We hypothesized that aliskiren provides renoprotection in diabetic animals that did not receive sufficient renoprotection by AT1-receptor antagonist treatment. Type 2 diabetic KKAy mice were treated with group 1: vehicle or group 2: valsartan (15 mg/kg per day) from 12 to 16 weeks of age. The mice were subsequently divided into 4 groups and treated with the following combinations of drugs for another 6 weeks: 1: group 1 kept receiving vehicle, 2: group 2 continuously received 15 mg/kg per day of valsartan (Val-Val15), 3: group 2 received 50 mg/kg per day of valsartan (Val-Val50), 4: group 2 continuously received 15 mg/kg per day of valsartan with 25 mg/kg per day of aliskiren (Val-Val+Ali). Aliskiren exerted significant anti-albuminuric effects, whereas valsartan failed to ameliorate the albuminuria in the first four weeks. Surprisingly, the increasing dosage of valsartan in the Val-Val50 group showed non-significant tendencies to attenuate the albuminuria compared with vehicle infusion. Val-Val+Ali significantly suppressed the development of albuminuria and podocyte injury. Val-Val50 and Val-Val+Ali showed similar suppression of angiotensin II contents in the kidney of KKAy mice. In conclusion, the anti-albuminuric effect that was observed in the type 2 diabetic mice showing no anti-albuminuric effect by valsartan can be attributed to the add-on aliskiren. Keywords:: aliskiren, valsartan, diabetic nephropathy

We recently demonstrated that cilnidipine, an L/N-type calcium channel blocker, elicits protective effects against glomerular podocyte injury, in particular, in obese hypertensive rats that express the N-type calcium channel (N-CC). Since the N-CC is known to be expressed in sympathetic nerve endings, we evaluated the reno-protective effects of cilnidipine in innervated and denervated spontaneously hypertensive rats (SHR). Male SHR were uninephrectomized and fed 4% high-salt diet (HS-UNX-SHR). Animals were divided into groups, as follows, and observed from 9 to 27 weeks of age: 1) vehicle (n = 14), 2) vehicle plus renal-denervation (n = 15), 3) cilnidipine (50 mg/kg per day, p.o.; n = 10), and 4) cilnidipine plus renal-denervation (n = 15). Renal denervation attenuated elevations in blood pressure, but failed to suppress urinary protein excretion and podocyte injury in HS-UNX-SHR. Cilnidipine in both innervated and denervated HS-UNX-SHR similarly induced significant antihypertensive effects, as well as suppressing the urinary protein excretion and podocyte injury, compared to vehicle-treated HS-UNX-SHR. These data indicate that renal nerves have a limited contribution to the cilnidipine-induced reno-protective effects in HS-UNX-SHR. Keywords:: cilnidipine, hypertension, N-type calcium channel, podocyte, renal sympathetic nerve

Urinary excretion of albumin (UAlb) is used clinically as a marker of diabetic nephropathy (DN). Although DN was thought to be a unidirectional process, recent studies demonstrated that a large proportion of patients diagnosed with DN reverted to normoalbuminuria. Moreover, despite the normoalbuminuria, one-third of them exhibited reduced renal function even during the microalbuminuric stage. This study was performed to investigate whether urinary angiotensinogen (UAGT) level may serve as a useful marker of the early stage of experimental type 1 diabetes (T1DM). T1DM was induced by a single intraperitoneal injection of streptozotocin. Control mice were injected with citrate buffer. Two days after streptozotocin injection, half of the mice received continuous insulin treatment. Our data showed that UAlb excretion was increased 6 days after streptozotocin injection compared to controls, whereas UAGT excretion was increased at an earlier time point. These increases were reversed by insulin treatment. The UAGT to UAlb ratio was increased in diabetic mice compared to control mice. Furthermore, the increased AGT expression in the kidneys was observed in diabetic mice. These data suggest that UAGT might be useful as a novel early biomarker of activation of the renin–angiotensin system in experimental type 1 diabetes. Keywords:: streptozotocin-induced type 1 diabetic mice, angiotensinogen, biomarker, renin–angiotensin system, diabetic nephropathy

Abstract.: Transforming growth factor beta-1 (TGF-β1) plays a critical role in progression of cardiac fibrosis, which may involve intracellular calcium change. We examined effects of efonidipine, a dual T-type and L-type calcium channel blocker (CCB), on TGF-β1–induced fibrotic changes in neonatal rat cardiac fibroblast. T-type and L-type calcium channel mRNAs were highly expressed in cultured cardiac fibroblasts. TGF-β1 (5 ng/mL) significantly increased Smad2 phosphorylation and [3H]-leucine incorporation, which were attenuated by pretreatment with efonidipine (10 μM). Neither R(−)efonidipine (10 μM), selective T-type CCB, nor nifedipine (10 μM), selective L-type CCB, efficaciously inhibited both TGF-β1–induced Smad2 phosphorylation and [3H]-leucine incorporation. However, both were markedly attenuated by combination of R(−)efonidipine and nifedipine, EDTA, or calcium-free medium. Pretreatment with Smad2 siRNA significantly attenuated [3H]-leucine incorporation induced by TGF-β1. These data suggest that efonidipine elicits inhibitory effects on TGF-β1–and Smad2-dependent protein synthesis through both T-type and L-type calcium channel–blocking actions in cardiac fibroblasts. Keywords:: transforming growth factor beta-1, Smad2, T-type calcium channel, cardiac fibrosis, efonidipine

The morning surge in blood pressure (BP) coincides with increased cardiovascular (CV) events. This strongly suggests that an altered circadian rhythm of BP plays a crucial role in the development of CV disease (CVD). A disrupted circadian rhythm of BP, such as the non-dipping type of hypertension (i.e., absence of nocturnal BP decline), is frequently observed in metabolic disorders and chronic kidney disease (CKD). The circadian timing system, controlled by the central clock in the suprachiasmatic nucleus of the hypothalamus and/or by peripheral clocks in the heart, vasculature, and kidneys, modulates the 24 h oscillation of BP. However, little information is available regarding the molecular and cellular mechanisms of an altered circadian timing system-mediated disrupted dipping pattern of BP in metabolic disorders and CKD that can lead to the development of CV events. A more thorough understanding of this pathogenesis could provide novel therapeutic strategies for the management of CVD. This short review will address our and others’ recent findings on the molecular mechanisms that may affect the dipping pattern of BP in metabolic dysfunction and kidney disease and its association with CV disorders.

Recent studies indicate a role of chymase in the regulation of angiotensin II (AngII) formation in cardiovascular and renal tissues. We investigated a possible contribution of chymase to AngII formation and to renal fibrosis in unilateral ureteral obstruction (UUO). Eight-week-old Syrian hamsters were subjected to UUO and treated with vehicle, the specific chymase inhibitor (CI) 4-[1-(4-methyl-benzo[b]thiophen-3-ylmethyl)-1H-benzimidazol-2-ylsulfanyl]-butyric acid (50 mg/kg, twice a day, p.o.), or the selective AT1-receptor blocker olmesartan (10 mg/kg per day, p.o.) for 14 days. UUO-induced renal interstitial fibrosis was associated with increases in renal mRNA levels of α-smooth muscle actin (SMA), type I collagen, and transforming growth factor (TGF)-β. The UUO hamsters showed markedly higher AngII contents and increased AT1-receptor mRNA level in the obstructed kidney than sham-operated ones. In contrast, angiotensin-converting enzyme (ACE) protein expression was significantly lower in UUO hamsters. In UUO hamsters, treatment with CI or olmesartan significantly decreased AngII levels in renal tissue and mRNA levels of α-SMA, type I collagen, and TGF-β and ameliorated tubulointerstitial injury. On the other hand, neither CI nor olmesartan changed systolic blood pressure, renal ACE, and AT1-receptor protein levels. These data suggest that chymase-dependent intrarenal AngII formation contributes to the pathogenesis of interstitial fibrosis in obstructed kidneys of hamsters. Keywords:: chymase, angiotensin II, angiotensin-converting enzyme, unilateral ureteral obstruction

Background. The aims of this study were (1) to examine the renoprotective effects of alogliptin and (2) to establish urinary angiotensinogen (AGT) as a prognostic marker of renoprotective effects of alogliptin in patients with type 2 diabetes (T2D). Methods. In 43 patients with T2D (18 women, 66.1±1.71 years), 25 mg/day of alogliptin was added to the traditional hypoglycemic agents and/or nondrug treatments. Urinary concentrations of albumin (Alb) and AGT, normalized by urinary concentrations of creatinine (Cr) (UAlbCR and UAGTCR, respectively), were measured before and after the 12-week alogliptin treatment. Results. Alogliptin treatment tended to decrease UAlbCR (99.6±26.8 versus 114.6±36.0 mg/g Cr, P=0.198). Based on % change in UAlbCR, patients were divided into two groups, responders (

A growing body of evidence indicates that renal tissue injuries are reversible. We investigated whether dietary salt reduction with the combination therapy of angiotensin II type 1 receptor blocker (ARB) plus calcium channel blocker (CCB) reverses renal tissue injury in Dahl salt-sensitive (DSS) hypertensive rats. DSS rats were fed a high-salt diet (HS; 4% NaCl) for 4 weeks. Then, DSS rats were given one of the following for 10 weeks: HS diet; normal-salt diet (NS; 0.5% NaCl), NS + an ARB (olmesartan, 10 mg/kg/day), NS + a CCB (azelnidipine, 3 mg/kg/day), NS + olmesartan + azelnidipine or NS + hydralazine (50 mg/kg/day). Four weeks of treatment with HS diet induced hypertension, proteinuria, glomerular sclerosis and hypertrophy, glomerular podocyte injury, and tubulointerstitial fibrosis in DSS rats. A continued HS diet progressed hypertension, proteinuria and renal tissue injury, which was associated with inflammatory cell infiltration and increased proinflammatory cytokine mRNA levels, NADPH oxidase activity and NADPH oxidase-dependent superoxide production in the kidney. In contrast, switching to NS halted the progression of hypertension, renal glomerular and tubular injuries. Dietary salt reduction with ARB or with CCB treatment further reduced blood pressure and partially reversed renal tissues injury. Furthermore, dietary salt reduction with the combination of ARB plus CCB elicited a strong recovery from HS-induced renal tissue injury including the attenuation of inflammation and oxidative stress. These data support the hypothesis that dietary salt reduction with combination therapy of an ARB plus CCB restores glomerular and tubulointerstitial injury in DSS rats.

Diabetic nephropathy (DN) is the major cause of end-stage renal failure. Oxidative stress is implicated in the pathogenesis of DN. Nitrosonifedipine (NO-NIF) is a weak calcium channel blocker that is converted from nifedipine under light exposure. Recently, we reported that NO-NIF has potential as a novel antioxidant with radical scavenging abilities and has the capacity to treat vascular dysfunction by exerting an endothelial protective effect. In the present study, we extended these findings by evaluating the efficacy of NO-NIF against DN and by clarifying the mechanisms of its antioxidative effect. In a model of type 2 DN (established in KKAy mice), NO-NIF administration reduced albuminuria and proteinuria as well as glomerular expansion without affecting glucose metabolism or systolic blood pressure. NO-NIF also suppressed renal and systemic oxidative stress and decreased the expression of intercellular adhesion molecule (ICAM)-1, a marker of endothelial cell injury, in the glomeruli of the KKAy mice. Similarly, NO-NIF reduced albuminuria, oxidative stress, and ICAM-1 expression in endothelial nitric oxide synthase (eNOS) knockout mice. Moreover, NO-NIF suppressed urinary angiotensinogen (AGT) excretion and intrarenal AGT protein expression in proximal tubular cells in the KKAy mice. On the other hand, hyperglycemia-induced mitochondrial superoxide production was not attenuated by NO-NIF in cultured endothelial cells. These findings suggest that NO-NIF prevents the progression of type 2 DN associated with endothelial dysfunction through selective antioxidative effects.

This study was performed to demonstrate urinary angiotensinogen as a potential prognostic marker of the albuminuria reduction effects of olmesartan in patients with metabolic syndrome. In 24 patients (eight women, 57.88 ± 2.00 years), 5–40 mg/day of olmesartan were given. Urinary concentrations of albumin and angiotensinogen (normalized by urinary concentrations of creatinine) and plasma renin activity were measured before and after the 12- and 24-week marks of olmesartan treatment. Olmesartan treatment increased plasma renin activity and decreased urinary albumin and urinary angiotensinogen significantly (p < 0.05). Based on the % change in urinary albumin, patients were divided into two groups, responders (

Recent clinical trials have demonstrated that combination therapy with renin-angiotensin system inhibitors plus calcium channel blockers (CCBs) elicits beneficial effects on cardiovascular and renal events in hypertensive patients with high cardiovascular risks. In the present study, we hypothesized that CCB enhances the protective effects of an angiotensin II type 1 receptor blocker (ARB) against diabetic cerebrovascular-renal injury. Saline-drinking type 2 diabetic KK-A(y) mice developed hypertension and exhibited impaired cognitive function, blood-brain barrier (BBB) disruption, albuminuria, glomerular sclerosis and podocyte injury. These brain and renal injuries were associated with increased gene expression of NADPH oxidase components, NADPH oxidase activity and oxidative stress in brain and kidney tissues as well as systemic oxidative stress. Treatment with the ARB, olmesartan (10 mg/kg/day) reduced blood pressure in saline-drinking KK-A(y) mice and attenuated cognitive decline, BBB disruption, glomerular injury and albuminuria, which were associated with a reduction of NADPH oxidase activity and oxidative stress in brain and kidney tissues as well as systemic oxidative stress. Furthermore, a suppressive dose of azelnidipine (3 mg/kg/day) exaggerated these beneficial effects of olmesartan. These data support the hypothesis that a CCB enhances ARB-associated cerebrovascular-renal protective effects through suppression of NADPH oxidase-dependent oxidative stress in type 2 diabetes.

Mineralocorticoid receptor (MR) antagonists attenuate renal injury in salt-sensitive hypertensive rats with low plasma aldosterone levels. We hypothesized that oxidative stress causes MR activation in high-salt-fed Dahl salt-sensitive rats. Furthermore, we determined if MR activation persisted and induced renal injury, even after switching from a high- to a normal-salt diet.High-salt feeding for 4 weeks increased dihydroethidium fluorescence (DHE, an oxidant production marker), p22phox (a NADPH oxidase subunit) and serum and glucocorticoid-regulated kinase-1 (SGK1, an MR transcript) in glomeruli, compared with normal-salt feeding, and these changes persisted 4 weeks after salt withdrawal. Tempol treatment (0.5 mmol/L) during high-salt feeding abolished the changes in DHE fluorescence, p22phox and SGK1. Dietary salt reduction after a 4-week high-salt diet decreased both blood pressure and proteinuria, but was associated with significantly higher proteinuria than in normal control rats at 4 weeks after salt reduction. Administration of tempol during high-salt feeding, or eplerenone, an MR antagonist (100 mg/kg/day), started after salt reduction, recovered proteinuria to normal levels at 4 weeks after salt reduction. Paraquat, a reactive oxygen species generator, enhanced MR transcriptional activity in cultured rat mesangial cells and mouse podocytes.These results suggest that oxidative stress plays an important role in glomerular MR activation in Dahl salt-sensitive rats. Persistent MR activation even after reducing salt intake could limit the beneficial effects of salt restriction.

Objective To demonstrate that the administration of an angiotensin (Ang) II type 1 receptor (AT1R) blocker (ARB) inhibits the vicious cycle of high glucose (HG)-reactive oxygen species (ROS)-angiotensinogen (AGT)-Ang II-AT1R-ROS by suppressing ROSs and inflammation, thus ameliorating diabetic nephropathy (DN). Research Design and Methods Thirteen hypertensive DN patients were administered ARBs, and the following parameters were evaluated before and 16 weeks after the treatment: urinary AGT (UAGT), albumin (albumin-creatinine ratio: ACR), 8-hydroxydeoxyguanosine (8-OHdG), 8-epi-prostaglandin F2α (8-epi-PGF2α), monocyte chemoattractant protein (MCP)-1, interleukin (IL)-6, and IL-10. Results ARB treatment reduced the blood pressure and urinary levels of AGT, ACR, 8-OHdG, 8-epi-PGF2α, MCP-1, and IL-6 but increased the urinary levels of IL-10. The reduction rate of UAGT correlated with the reduction rate of blood pressure; the reduction rates of the urinary ACR, 8-OHdG, 8-epi-PGF2α, MCP-1, and IL-6 levels; and the increase rate of the urinary IL-10 levels. Moreover, subjects who had high UAGT values at baseline exhibited higher reduction rates of urinary albumin excretion. Conclusions ARB-induced blockade of the abovementioned vicious cycle contributes to the renoprotective effects of ARBs in DN. The urinary levels of AGT could represent a predictive factor for reduced ACR in patients receiving ARB treatment.