Effects of empagliflozin on blood pressure and markers of arterial stiffness and vascular resistance in patients with type 2 diabetes.

AIMS: To determine the effects of empagliflozin on blood pressure (BP) and markers of arterial stiffness and vascular resistance in patients with type 2 diabetes mellitus (T2DM). METHODS: We conducted a post hoc analysis of data from a phase III trial in patients with T2DM and hypertension receiving 12 weeks' empagliflozin and four phase III trials in patients with T2DM receiving 24 weeks' empagliflozin (cohort 1, n = 823; cohort 2, n = 2477). BP was measured using 24-h BP monitoring (cohort 1) or seated office measurements (cohort 2). RESULTS: Empagliflozin reduced systolic BP (SBP) and diastolic BP in both cohorts (p < 0.001 vs placebo), without increasing heart rate. Empagliflozin reduced pulse pressure (PP; adjusted mean difference vs placebo cohort 1: -2.3 mmHg; cohort 2: -2.3 mmHg), mean arterial pressure (MAP; cohort 1, -2.3 mmHg; cohort 2, -2.1 mmHg) and double product (cohort 1, -385 mmHg × bpm; cohort 2, -369 mmHg × bpm) all p < 0.001 vs placebo. There was a trend towards a reduction in the ambulatory arterial stiffness index (AASI) with empagliflozin in cohort 1 (p = 0.059 vs placebo). AASI was not measured in cohort 2. Subgroup analyses showed that there were greater reductions in PP with increasing baseline SBP in cohort 1 (p = 0.092). In cohort 2, greater reductions in MAP were achieved in patients with higher baseline SBP (p = 0.027) and greater reductions in PP were observed in older patients (p = 0.011). CONCLUSIONS: Empagliflozin reduced BP and had favourable effects on markers of arterial stiffness and vascular resistance.

Estimated glomerular filtration rate (eGFR) as a predictor of outcome after infrainguinal bypass in patients with critical limb ischemia.

OBJECTIVES: Renal insufficiency is a risk factor for poor outcome after infrainguinal bypass in patients with critical limb ischemia (CLI). Estimated glomerular filtration rate (eGFR) takes age, gender and body size into account and therefore represents actual renal function more accurately than serum creatinine level alone. The aim of this study was to determine the impact of different stages of renal insufficiency on outcome and to assess the prognostic significance of eGFR in patients with CLI. MATERIAL AND METHODS: 603 patients with CLI who underwent infrainguinal bypass between January 2002 and December 2005 at our institution were included in this retrospective study. We estimated GFR using the Modification of Diet in Renal Disease (MDRD) Study equation. Survival, leg salvage and amputation-free survival were calculated using Kaplan-Meier method. Cox regression analysis was performed to calculate hazard ratios for different outcome variables. RESULTS: Adjusted hazard ratio (HR) of mortality, limb loss and limb loss and/or death for eGFR < 30 ml/min/1.73 m(2) versus serum creatinine > 200 micromol/l was 4.0 (95% CI 2.22-7.39) vs 3.5 (95% CI 1.82-6.84), 6.5 (95% CI 2.71-15.59) vs 6.2 (95% CI 2.47-15.56) and 4.0 (95% CI 2.40-6.63) vs 3.6 (95% CI 2.03-6.25), respectively. CONCLUSION: Estimated GFR is better predictor of survival, leg salvage and amputation-free survival than serum creatinine alone. eGFR < 30 ml/min/1.73 m(2) is independent risk factor for all three outcome endpoints.

Paricalcitol aggravates perivascular fibrosis in rats with renal insufficiency and low calcitriol.

Cardiovascular complications are a major problem in chronic renal failure. We examined the effects of plasma calcium, phosphate, parathyroid hormone (PTH), and calcitriol on cardiac morphology in 5/6 nephrectomized rats. Fifteen weeks after nephrectomy rats were given a control diet, high-calcium or -phosphorus diet, or given paricalcitol treatment for 12 weeks. Sham-operated rats were on a control diet. Blood pressure, plasma phosphate, and PTH were increased, while the creatinine clearance was reduced in remnant kidney rats. Phosphate and PTH were further elevated by the high-phosphate diet but suppressed by the high-calcium diet, while paricalcitol reduced PTH without influencing phosphate or calcium. The high-calcium diet increased, while the high-phosphate diet reduced plasma calcium. Plasma calcitriol was significantly reduced in other remnant kidney groups, but further decreased after paricalcitol. Cardiac perivascular fibrosis and connective tissue growth factor were significantly increased in the remnant kidney groups, and further increased in paricalcitol-treated rats. Hence, regardless of the calcium, phosphate, or PTH levels, cardiac perivascular fibrosis and connective tissue growth factor increase in rats with renal insufficiency in association with low calcitriol. Possible explanations are that aggravated perivascular fibrosis after paricalcitol in renal insufficiency may be due to further suppression of calcitriol, or to a direct effect of the vitamin D analog.

Sustained cardiomyocyte apoptosis and left ventricular remodelling after myocardial infarction in experimental diabetes.

AIMS/HYPOTHESIS: Diabetes is known to reduce survival after myocardial infarction. Our aim was to examine whether diabetes is associated with enhanced cardiomyocyte apoptosis and thus interferes with the post-infarction remodelling process in myocardium in rat. METHODS: Four weeks after intravenous streptozotocin (diabetic groups) or citrate buffer (controls) injection, myocardial infarction was produced by ligation of left descending coronary artery. Level of cardiomyocyte apoptosis was quantified by TUNEL and caspase-3 methods. Collagen volume fraction and connective tissue growth factor were determined under microscope. Left ventricular dimensions were evaluated by echocardiography and planimetry. RESULTS: The number of apoptotic cardiomyocytes was equally high in diabetic and non-diabetic rats after 1 week from infarction. At 12 weeks after infarction the number of apoptotic cells was higher in the diabetic as compared to non-diabetic rats both in the border zone of infarction and in non-infarcted area. Correspondingly, left ventricular end diastolic diameter, relative cardiac weight, connective tissue growth factor-expression and fibrosis were increased in diabetic compared with non-diabetic rats with myocardial infarction. CONCLUSION/INTERPRETATION: Sustained cardiomyocyte apoptosis, left ventricular enlargement, increased cardiac fibrosis and enhanced profibrogenic connective tissue growth factor expression were detected after myocardial infarction in experimental diabetes. Apoptotic myocyte loss could be an important mechanism contributing to progressive dilatation of the heart and poor prognosis after myocardial infarction in diabetes.

Vascular effects of COX inhibition and AT1 receptor blockade in transgenic rats harboring mouse renin-2 gene.

Ang II-induced endothelial dysfunction is associated with perivascular inflammation and increased superoxide production in the vascular wall. The present study examined the role of cyclo-oxygenase (COX)-synthetized eicosanoids in the pathogenesis of Ang II-induced endothelial dysfunction in transgenic rats harboring mouse renin-2 gene (mREN2 rats). Five-to-six-week-old, heterozygous mREN2 rats received the following drug regimens for 8 weeks: 1) vehicle, 2) cyclo-oxygenase-2 (COX-2) inhibitor (MF-tricyclic [3-(3,4-difluorophenyl)-4-(4-(methylsulfonyl) phenyl)-2(5H)-furanone], 14 mg/kg p.o.), 3) COX-1/COX-2 inhibitor (sulindac, 14 mg/kg p.o.), 4) angiotensin II receptor antagonist (losartan 40 mg/kg p.o.). Normotensive Sprague Dawley (SD) rats served as controls. In vitro vascular responses of the descending aorta and renal artery were studied using organ bath system. mREN2 rats developed pronounced hypertension which was associated with impaired endothelium-dependent and endothelium-independent vascular relaxations in the aorta. In contrast, the relaxation responses of the renal arteries remained largely unchanged in mREN2 rats. Urinary NO, excretion, a marker of total body NO generation, was also decreased in mREN2 rats. Neither non-selective COX inhibitor sulindac nor COX-2 selective MF-tricyclic were capable of preventing Ang II-induced hypertension or endothelial dysfunction in mREN2 rats, whereas ATi receptor antagonist losartan completely normalized blood pressure, vascular relaxation responses as well as urinary NOx excretion. Our findings indicate that NO synthesis and/or bioavailability as well as the sensitivity of arterial smooth muscle cells to NO are decreased in mREN2 rats. The present study also demonstrated that COX does not play a central role in the pathogenesis of Ang II-induced endothelial dysfunction in mREN2 rats.

Clonidine provides opioid-sparing effect, stable hemodynamics, and renal integrity during laparoscopic cholecystectomy.

BACKGROUND: Carbon dioxide pneumoperitoneum causes a hemodynamic stress response and decreases urine output because of an activated renin-angiotensin-aldosterone system (RAAS). Clonidine is a potent antihypertensive drug that suppresses RAAS. METHODS: The effects of clonidine 4.5 mg/kg or saline on hemodynamics, neuroendocrine response, and renal parameters were compared in 30 healthy patients undergoing laparoscopic cholecystectomy. RESULTS: Heart rate, arterial blood pressures, and plasma renin activity were lower during and after pneumoperitoneum in patients with clonidine. There were no differences in urine output, urine oxygen tension (reflecting medullary perfusion), or antidiuretic hormone between the groups. N-acetyl-b-D-glucosaminidase, a marker of proximal tubular damage, was minimally elevated after clonidine. CONCLUSIONS: Clonidine enabled stable hemodynamics and prevented activation of RAAS seen as unchanged plasma renin activity. Clonidine may be beneficial during laparoscopy in patients with hypertension, cardiovascular, and/or renal diseases.

Dual inhibition of angiotensin converting enzyme and neutral endopeptidase by omapatrilat in rat in vivo.

The pharmacological profile of a vasopeptidase inhibitor is dependent on the ratio of neutral endopeptidase (NEP)vs angiotensin converting enzyme (ACE) inhibition of the particular drug. We used in vitro autoradiography to determine the local renal and cardiac NEP and ACE inhibition after oral treatment with the dual NEP/ACE inhibitor omapatrilat in rat. Maximal inhibition of both renal NEP and ACE was achieved at the omapatrilat dose of 40 mg kg(-1)day(-1). Effective local ACE inhibition was detected also in the myocardium. The haemodynamic effects were similar to captopril, but omapatrilat treatment produced more favorable effect on natriuretic peptide levels. In conclusion, good tissue penetration of omapatrilat and balanced NEP/ACE inhibition may prove to be useful in the treatment of hypertension and heart failure.

Changes in the expression of nephrin gene and protein in experimental diabetic nephropathy.

Diabetic nephropathy is a major complication of diabetes leading to thickening of the glomerular basement membrane, glomerular hypertrophy, mesangial expansion, and overt renal disease. The pathophysiologic mechanisms of diabetic nephropathy remain poorly understood. Nephrin is a recently found podocyte protein crucial for the interpodocyte slit membrane structure and maintenance of an intact filtration barrier. Here we have assessed the role of nephrin in two widely used animal models of diabetes, the streptozotocin model of the rat and the nonobese diabetic mouse. In both models, the expression levels of nephrin-specific mRNA as determined by real-time quantitative polymerase chain reaction increased up to two-fold during several weeks of follow-up. Immunohistochemical stainings revealed nephrin also more centrally within the glomerular tuft along with its preferential site in podocytes. Interestingly, as detected by immunoblotting, nephrin protein was also found in the urine of streptozotocin-induced rats. We conclude that nephrin is connected to the early changes of diabetic nephropathy and thus may contribute to the loss of glomerular filtration function.

Vasopeptidase inhibition attenuates the progression of renal injury in subtotal nephrectomized rats.

BACKGROUND: Vasopeptidase inhibitors are a new class of cardiovascular compounds that inhibit both angiotensin-converting enzyme (ACE) and neutral endopeptidase (NEP). The aim of the present study was to explore the effects of omapatrilat, a vasopeptidase inhibitor, on renal function and pathology in subtotally nephrectomized (STNx) rats. METHODS: STNx rats were randomized to four groups and treated for 12 weeks: no treatment (N = 14); omapatrilat at a low dose of 10 mg/kg (L, N = 12) and at a high dose of 40 mg/kg (H, N = 10); or an ACE inhibitor, fosinopril, at a dose of 10 mg/kg (N = 12). Sham-operated rats were used as control animals (N = 12). RESULTS: Elevated blood pressure in STNx rats (174 +/- 9 mm Hg) was reduced by omapatrilat in a dose-dependent manner (L, 121 +/- 3 mm Hg; H, 110 +/- 3 mm Hg) and by fosinopril (149 +/- 5 mm Hg). Proteinuria in STNx rats (246 +/- 73 mg/day) was reduced by treatment with fosinopril (88 +/- 21 mg/day) and was normalized by treatment with omapatrilat (L, 30 +/- 4 mg/day; H, 20 +/- 2 mg/day vs. control 25 +/- 1 mg/day). Decreased glomerular filtration rates, elevated plasma urea and creatinine and glomerulosclerosis, and tubulointerstitial fibrosis were ameliorated by omapatrilat and fosinopril to a similar degree. Compared with fosinopril, omapatrilat treatment was associated with increased plasma renin activity and decreased renal ACE and NEP binding in a dose-dependent manner. CONCLUSION: These findings suggest that vasopeptidase inhibition may provide a useful strategy for the treatment of progressive renal disease.

Cardiomyocyte apoptosis and ventricular remodeling after myocardial infarction in rats.

We investigated the role of cardiomyocyte apoptosis in the remodeling of the left ventricle from 24 h to 12 wk after myocardial infarction in the rat. Infarct size planimetry, quantification of cardiomyocyte apoptosis, terminal deoxynucleotide transferase-mediated dUTP nick-end labeling (TUNEL) methodology, and echocardiography (left ventricular diastolic diameter and ejection fraction) were performed. Sham-operated animals showed low rates of cardiomyocyte apoptosis (0.03%) and no change in diastolic diameter or ejection fraction during the study. Twenty-four hours after infarction, TUNEL positivity was high in the infarct areas (1.4%) and border zones (4.9%). It declined to 0.34% (P < 0.01 vs. sham) at 4 wk and 0.10% at 12 wk in the border zones. In the remote myocardium, cardiomyocyte apoptosis increased to 0.07% (P = 0.03 vs. sham) on day 1 and remained on the same level up to 4 wk. The increase in diastolic diameter 1-4 wk after infarction correlated (r = 0.60, P < 0.01) with cardiomyocyte apoptosis in the noninfarcted myocardium, which quantitatively contributed most (>50%) to the apoptotic cell loss by 4 wk.

Endothelial dysfunction and xanthine oxidoreductase activity in rats with human renin and angiotensinogen genes.

We examined whether xanthine oxidoreductase (XOR), a hypoxia-inducible enzyme capable of generating reactive oxygen species, is involved in the onset of angiotensin (Ang) II-induced vascular dysfunction in double-transgenic rats (dTGR) harboring human renin and human angiotensinogen genes. In 7-week-old hypertensive dTGR, the endothelium-mediated relaxation of noradrenaline (NA)-precontracted renal arterial rings to acetylcholine (ACh) in vitro was markedly impaired compared with Sprague Dawley rats. Preincubation with superoxide dismutase (SOD) improved the endothelium-dependent vascular relaxation, indicating that in dTGR, endothelial dysfunction is associated with increased superoxide formation. Preincubation with the XOR inhibitor oxypurinol also improved endothelium-dependent vascular relaxation. The endothelium-independent relaxation to sodium nitroprusside was similar in both strains. In dTGR, serum 8-isoprostaglandin F(2alpha), a vasoconstrictor and antinatriuretic arachidonic acid metabolite produced by oxidative stress, was increased by 100%, and the activity of XOR in the kidney was increased by 40%. Urinary nitrate plus nitrite (NO(x)) excretion, a marker of total body NO generation, was decreased by 85%. Contractile responses of renal arteries to Ang II, endothelin-1 (ET-1), and NA were decreased in dTGR, suggesting hypertension-associated generalized changes in the vascular function rather than a receptor-specific desensitization. Valsartan (30 mg/kg PO for 3 weeks) normalized blood pressure, endothelial dysfunction, and the contractile responses to ET-1 and NA. Valsartan also normalized serum 8-isoprostaglandin F(2alpha) levels, renal XOR activity, and, to a degree, NO(x) excretion. Thus, overproduction of Ang II in dTGR induces pronounced endothelial dysfunction, whereas the sensitivity of vascular smooth muscle cells to nitric oxide is unaltered. Ang II-induced endothelial dysfunction is associated with increased oxidative stress and vascular xanthine oxidase activity.

Endothelial dysfunction and salt-sensitive hypertension in spontaneously diabetic Goto-Kakizaki rats.

Endothelial dysfunction is associated with hypertension, hypercholesterolemia, and heart failure. We tested the hypothesis that spontaneously diabetic Goto-Kakizaki (GK) rats, a model for type 2 diabetes, exhibit endothelial dysfunction. Rats also received a high-sodium diet (6% NaCl [wt/wt]) and chronic angiotensin type 1 (AT(1)) receptor blockade (10 mg/kg PO valsartan for 8 weeks). Compared with age-matched nondiabetic Wistar control rats, GK rats had higher blood glucose levels (9.3+/-0.5 versus 6.9+/-0.2 mmol/L for control rats), 2.7-fold higher serum insulin levels, and impaired glucose tolerance (all P<0.05). Telemetry-measured mean blood pressure was 15 mm Hg higher in GK rats (P<0.01) compared with control rats, whereas heart rates were not different. Heart weight- and kidney weight-to-body weight ratios were higher in GK rats (P<0.05), and 24-hour albuminuria was increased 50%. Endothelium-mediated relaxation of noradrenaline-precontracted mesenteric arterial rings by acetylcholine was impaired compared with the control condition (P<0.05), whereas the sodium nitroprusside-induced relaxation was similar. Preincubation of the arterial rings with the NO synthase inhibitor N(G)-nitro-L-arginine methyl ester and the cyclooxygenase inhibitor diclofenac inhibited relaxations to acetylcholine almost completely in GK rats but not in Wistar rats, suggesting that endothelial dysfunction can be in part attributed to reduced relaxation via arterial K(+) channels. Perivascular monocyte/macrophage infiltration and intercellular adhesion molecule-1 overexpression were observed in GK rat kidneys. A high-sodium diet increased blood pressure by 24 mm Hg and 24-hour albuminuria by 350%, induced cardiac hypertrophy, impaired endothelium-dependent relaxation further, and aggravated inflammation (all P<0.05). The serum level of 8-isoprostaglandin F(2alpha), a vasoconstrictor and antinatriuretic arachidonic acid metabolite produced by oxidative stress, was increased 400% in GK rats on a high-sodium diet. Valsartan decreased blood pressure in rats fed a low-sodium diet and prevented the inflammatory response. In rats fed a high-sodium diet, valsartan did not decrease blood pressure or improve endothelial dysfunction but protected against albuminuria, inflammation, and oxidative stress. As measured by quantitative autoradiography, AT(1) receptor expression in the medulla was decreased in GK compared with Wistar rats, whereas cortical AT(1) receptor expression, medullary and cortical angiotensin type 2 (AT(2)) receptor expressions, and adrenal ACE and neutral endopeptidase expressions were unchanged. A high-sodium diet did not influence renal AT(1), AT(2), ACE, or neutral endopeptidase expressions. In valsartan-treated GK rats, the cortical and medullary AT(1) receptor expressions were decreased in the presence and absence of a high-sodium diet. A high-sodium diet increased plasma brain natriuretic peptide concentrations in presence and absence of valsartan treatment. We conclude that hypertension in GK rats is salt sensitive and associated with endothelial dysfunction and perivascular inflammation. AT(1) receptor blockade ameliorates inflammation during a low-sodium diet and partially protects against salt-induced vascular damage by blood pressure-independent mechanisms.

Plasma and pericardial fluid natriuretic peptide levels in postinfarction ventricular dysfunction.

AIMS: In the present study we examined plasma and pericardial fluid ANP and BNP concentrations in postinfarction ventricular dysfunction. The association of peptide levels to left ventricular (LV) dysfunction and to the localization of the myocardial infarction (MI) was studied. METHODS AND RESULTS: Plasma and pericardial fluid samples were obtained from 37 patients undergoing coronary bypass surgery. According to the ECG and preceding coronary angiography, the patients were divided into three groups: previous anterior myocardial infarction (MI) (n=12), previous inferior/posterior MI (n=15) and no history of MI (n=10). When compared to the control group with no MI, the patients with anterior MI had elevated plasma ANP and BNP (134+/-13 vs. 81+/-15 pg/ml, P<0.01 and 95+/-10 pg/ml vs. 26+/-8 pg/ml, P<0.01, respectively) and pericardial fluid BNP (473+/-60 pg/ml vs. 57+/-8 pg/ml, P<0.001) levels. The plasma natriuretic peptide concentrations were not increased in the patients with inferior/posterior MI, but the pericardial fluid BNP concentrations were greater than in the patients with no history of MI (129+/-35 pg/ml vs. 57+/-8 pg/ml, P<0.05). Six of the 12 patients with previous anterior MI had LVEF> or =45%. Despite their normal LV systolic function, these patients had increased plasma and pericardial fluid BNP levels when compared to the group with no history of MI (68+/-18 pg/ml vs. 26+/-8 pg/ml, P<0.05 and 534+/-258 pg/ml vs. 57+/-8 pg/ml, P<0.01, respectively). CONCLUSIONS: Previous anterior myocardial infarction was associated with increased cardiac BNP production even if the LV systolic function was normal (LVEF> or =45%). The high pericardial fluid BNP concentrations in postinfarction patients suggest that the BNP synthesis and release are augmented in the ventricular myocardium independent from the LVEF.

Renin-angiotensin blockade improves renal cGMP production via non-AT(2)-receptor mediated mechanisms in hypertension-induced by chronic NOS inhibition in rat.

BACKGROUND: To investigate the changes in the angiotensin II (Ang II) receptors and nitric oxide (NO)-cGMP pathway in the rat kidney after nitric oxide synthase (NOS)blockade. METHODS: Captopril, an angiotensin-converting enzyme (ACE)inhibitor, 20 mg/100 ml; and/or L-158,809 (an Ang II AT1-receptor antagonist, 5 mg/100 ml) and L-NAME (NOS inhibitor, 50 mg/100 ml) were administered orally for 12 weeks. Blood pressure (BP),urinary albumin, urinary cGMP excretion, plasma ANP, and plasma renin activity were measured. In vitro autoradiography was used to locate the Ang II receptors in the kidney. RESULTS: Captopril and L- 158,809 treatments normalised BP and prevented the appearance of albuminuria in rats receiving L-NAME. Urinary cGMP excretion was significantly increased in L-158,809-treated rats compared with the non-treated group, suggesting that the dysfunctional NO system may be activated by the treatment. AT1-receptor binding in the kidney was inhibited to about 40% of the control value after administration of L- 158,809. The AT2-receptor binding was inhibited to less than 15% of the control value. NOS inhibition had no effect on receptor binding. CONCLUSION: Blockade of NOS causes hypertension and renal damage. Treatment with an ACE inhibitor and/or Ang II receptor antagonist prevented these changes equally effectively. The stimulatory effect of AT1-receptor antagonism on cGMP production was not mediated by AT2-receptor-dependent mechanisms, since renalAT2-receptor binding density was suppressed following treatment with L-158,809. AT1-receptor blockade per se favours activation of humoral pathways that stimulate cGMP production potentially contributing to renal and vascular protection in hypertension and chronic renal disease.

Randomised controlled trial of dual blockade of renin-angiotensin system in patients with hypertension, microalbuminuria, and non-insulin dependent diabetes: the candesartan and lisinopril microalbuminuria (CALM) study.

OBJECTIVES: To assess and compare the effects of candesartan or lisinopril, or both, on blood pressure and urinary albumin excretion in patients with microalbuminuria, hypertension, and type 2 diabetes. DESIGN: Prospective, randomised, parallel group, double blind study with four week placebo run in period and 12 weeks' monotherapy with candesartan or lisinopril followed by 12 weeks' monotherapy or combination treatment. SETTING: Tertiary hospitals and primary care centres in four countries (37 centres). PARTICIPANTS: 199 patients aged 30-75 years. INTERVENTIONS: Candesartan 16 mg once daily, lisinopril 20 mg once daily. MAIN OUTCOME MEASURES: Blood pressure and urinary albumin:creatinine ratio. RESULTS: At 12 weeks mean (95% confidence interval) reductions in diastolic blood pressure were 9.5 mm Hg (7.7 mm Hg to 11.2 mm Hg, P<0.001) and 9.7 mm Hg (7.9 mm Hg to 11.5 mm Hg, P<0.001), respectively, and in urinary albumin:creatinine ratio were 30% (15% to 42%, P<0.001) and 46% (35% to 56%, P<0.001) for candesartan and lisinopril, respectively. At 24 weeks the mean reduction in diastolic blood pressure with combination treatment (16.3 mm Hg, 13.6 mm Hg to 18.9 mm Hg, P<0. 001) was significantly greater than that with candesartan (10.4 mm Hg, 7.7 mm Hg to 13.1 mm Hg, P<0.001) or lisinopril (mean 10.7 mm Hg, 8.0 mm Hg to 13.5 mm Hg, P<0.001). Furthermore, the reduction in urinary albumin:creatinine ratio with combination treatment (50%, 36% to 61%, P<0.001) was greater than with candesartan (24%, 0% to 43%, P=0.05) and lisinopril (39%, 20% to 54%, P<0.001). All treatments were generally well tolerated. CONCLUSION: Candesartan 16 mg once daily is as effective as lisinopril 20 mg once daily in reducing blood pressure and microalbuminuria in hypertensive patients with type 2 diabetes. Combination treatment is well tolerated and more effective in reducing blood pressure.

Nephrin in experimental glomerular disease.

BACKGROUND: The recently identified gene NPHS1 with its mutations causing congenital nephrotic syndrome of the Finnish type (CNF) is highly promising in providing new understanding of pathophysiology of proteinuria. Earlier we cloned a rat NPHS1 homologue, as well as characterized and raised antibodies to the respective protein product nephrin. METHODS: Changes in the expression levels of nephrin-specific mRNA in commonly used experimental models of proteinuria were examined using semiquantitative reverse transcription-polymerase chain reaction, immunofluorescence, and immunoelectron microscopy (IEM) of nephrin. RESULTS: Notably, a 40% down-regulation of the nephrin-specific mRNA of cortical kidney was seen already at day 3 after induction of the puromycin aminonucleoside nephrosis (PAN), while no major elevation of urinary protein secretion was seen at this stage. A further decrease of 80% of nephrin message was seen at the peak of proteinuria at day 10. A similar decrease of up to 70% from the basal levels was seen in mercuric chloride-treated rats. Changes in the protein expression paralleled those of the mRNA in indirect immunofluorescence. Interestingly, a remarkable plasmalemmal dislocation from the normal expression site at the interpodocyte filtration slits could be observed in IEM. CONCLUSIONS: Nephrin appears to be an important causative molecule of proteinuria and shows a remarkable redistribution from the filtration slits to the podocyte plasma membrane, especially in PAN.

Predicting the outcome of invasive treatment of renal artery disease.

OBJECTIVE: Analysis of the factors influencing the outcome of performed or attempted invasive treatment for renal artery disease (RAD). SETTING: University Hospital. STUDY PATIENTS: Thirty-five hypertensive patients with 31 stenoses and 14 occlusions of renal artery. INTERVENTIONS: Angioplasty was performed on 25 patients (attempted for 30), primary stenting on one, nephrectomy on three, and renal resection on one patient. MAIN OUTCOME MEASURE: A decrease of diastolic blood pressure (DBP) by >/=15 mmHg after intervention. RESULTS: A DBP response was seen in 24 patients. In 11 patients, invasive treatment did not result in a DBP response or failed technically. Compared with these patients, the responders were younger (55 +/- 11 vs. 66 +/- 8 years, P = 0.001) and tended to have higher DBP (100 +/- 8 vs. 93 +/- 11 mmHg, P = 0.065). The function of the affected kidney, or that of the more affected kidney if RAD was bilateral, was better preserved in responders (relative clearance on captopril renography 23 +/- 15 vs. 8 +/- 4%, P = 0.008). A response was more often seen in unilateral than in bilateral RAD (81% vs. 33%, P = 0.015). A relative clearance of

Renoprotective effects of captopril in hypertension induced by nitric oxide synthase inhibition in experimental nephritis.

OBJECTIVE: To investigate effects of angiotensin I converting enzyme (ACE) inhibition in experimental nephritis during chronic inhibition of nitric oxide (NO) synthase. METHODS: Rats with and without autoimmune Heymann nephritis were treated with a NO synthase inhibitor L-NAME (50 mg/100 ml) and/or an ACE inhibitor captopril (20 mg/100 ml) in drinking water for 12 weeks. Urinary cGMP excretion was used as an indirect measure of NO activity. Blood pressure, urinary albumin, nitrite and nitrate levels, plasma ANP, and plasma renin activity were measured. Kidneys were examined with light microscopy and immunohistochemical methods. RESULTS: Captopril treatment protected rats receiving L-NAME and none of the captopril-treated rats died. Mortality was greatest in the nephritis-L-NAME (57%) and L-NAME (43%) groups. Captopril normalized cGMP excretion, blood pressure, and prevented partly the appearance of albuminuria. Peritubular infiltration of mononuclear cells was clearly enhanced in the nephritis-L-NAME group (found in 80% of the rats) as compared with the nephritis (20%), L-NAME (40%), and control (0%) groups. The peritubular cell infiltration caused by L-NAME was prevented by captopril treatment. L-NAME-induced hypertension was associated with cardiac hypertrophy and this was prevented by captopril. CONCLUSIONS: NO may play an important renoprotective role in disease progression of chronic membranous glomerulonephritis. Captopril prevents L-NAME-induced hypertension, improves survival, and ameliorates renal damage in this type of nephritis. Dysfunction of renal NO pathways may be an important factor causing progressive renal damage in chronic nephritis. Our results suggest that the dysfunctional renal NO system may be beneficially activated by ACE inhibitors.