Combined ASBT Inhibitor and FGF15 Treatment Improves Therapeutic Efficacy in Experimental Nonalcoholic Steatohepatitis.

BACKGROUND & AIMS: Pharmacologic agents targeting bile acid signaling show promise for treating nonalcoholic steatohepatitis (NASH). However, clinical findings suggest that new treatment strategies with enhanced therapeutic efficacy and minimized undesired effects are needed. This preclinical study investigates whether combining an apical sodium-bile acid transporter (ASBT) inhibitor GSK233072 (GSK672) and fibroblast growth factor-15 (FGF15) signaling activation improves anti-NASH efficacy. METHODS: Mice with high fat, cholesterol, and fructose (HFCFr) diet-induced NASH and stage 2 fibrosis are used as a NASH model. GSK672 or AAV8-TBG-FGF15 interventions are administered alone or in combination to HFCFr diet-fed mice. RESULTS: The combined treatment significantly enhances therapeutic efficacy against steatosis, inflammation, ballooning, and fibrosis than either single treatment. Mechanistically, the synergistic actions of GSK672 and FGF15 on inhibiting gut bile acid reuptake and hepatic bile acid synthesis achieve greater magnitude of bile acid pool reduction that not only decreases bile acid burden in NASH livers but also limits intestinal lipid absorption, which, together with FGF15 signaling activation, produces weight loss, reduction of adipose inflammation, and attenuated hepatocellular organelle stress. Furthermore, the combined treatment attenuates increased fecal bile acid excretion and repressed bile acid synthesis, which underlie diarrhea and hypercholesterolemia associated with ASBT inhibition and FGF19 analogue, respectively, in clinical settings. CONCLUSIONS: Concomitant ASBT inhibition and FGF15 signaling activation produce metabolic changes that partially mimic the bariatric surgery condition whereby lipid malabsorption and increased FGF15/19 signaling synergistically mediate weight loss and metabolic improvement. Further clinical studies may be warranted to investigate whether combining ASBT inhibitor and FGF19 analogue enhances anti-NASH efficacy and reduced treatment-associated adverse events in humans.

Discovery of Ziresovir as a Potent, Selective, and Orally Bioavailable Respiratory Syncytial Virus Fusion Protein Inhibitor.

Ziresovir (RO-0529, AK0529) is reported here for the first time as a promising respiratory syncytial virus (RSV) fusion (F) protein inhibitor that currently is in phase 2 clinical trials. This article describes the process of RO-0529 as a potent, selective, and orally bioavailable RSV F protein inhibitor and highlights the in vitro and in vivo anti-RSV activities and pharmacokinetics in animal species. RO-0529 demonstrates single-digit nM EC50 potency against laboratory strains, as well as clinical isolates of RSV in cellular assays, and more than one log viral load reduction in BALB/c mouse model of RSV viral infection. RO-0529 was proven to be a specific RSV F protein inhibitor by identification of drug resistant mutations of D486N, D489V, and D489Y in RSV F protein and the inhibition of RSV F protein-induced cell-cell fusion in cellular assays.

Anticonvulsant activity of the antidepressant drug, tianeptine, against pentylenetetrazole-induced seizures mitigates cognitive impairment in rats.

Treatment of depression, a common comorbidity in patients with epilepsy, is restricted as certain antidepressants are considered to be proconvulsants. In contrast, anticonvulsant effects have been reported with some antidepressants. In the present study, the effect of tianeptine, an antidepressant, was evaluated against pentylenetetrazole (PTZ)-induced seizures, cognitive impairment and oxidative stress in rats. Tianeptine was administered in three doses (20, 40 and 80 mg/kg) 30 min before PTZ (60 mg/kg, intraperitoneally). MK801, an N-methyl-D-aspartate antagonist, and naloxone, an opioid receptor antagonist, were administered with tianeptine to evaluate the involvement of N-methyl-D-aspartate and opioid receptors, respectively. Morris water maze, elevated plus maze and passive avoidance tests were performed for behavioural assessment. Brain malondialdehyde and reduced glutathione levels were estimated as markers of oxidative stress. Tianeptine showed dose-dependent protection against PTZ seizures. Coadministration of tianeptine with MK801 potentiated the anticonvulsant effect of tianeptine. The protective effect of tianeptine against PTZ seizures was mitigated when tianeptine was administered with naloxone. Impairment of learning and memory by PTZ was prevented by tianeptine. Tianeptine also attenuated the seizure-induced increased oxidative stress. Thus, tianeptine showed an anticonvulsant effect along with amelioration of seizure-induced cognitive impairment and oxidative stress. Hence, tianeptine could be a useful drug in epileptic patients with depression, with the advantage of having both antidepressant and antiepileptic effects.

Omapatrilat: penetration across the blood-brain barrier and effects on ischaemic stroke in rats.

Omapatrilat (OMA), which simultaneously inhibits the angiotensin-converting enzyme (ACE) and the neutral endopeptidase (neprilysin (NEP)), is widely used in experimental protocols related to hypertension and heart failure. The penetration of OMA across the blood-brain barrier (BBB) and the effects of ACE/NEP inhibition on the recovery from ischaemic stroke have not yet been investigated. Angiotensin (Ang) I injected intracerebroventricularly (ICV) or intravenously (IV) is converted to Ang II by ACE and induces an immediate increase in blood pressure. The pressor responses to OMA administered ICV, orally or IV were studied in male Wistar rats instrumented with an ICV and arterial and venous catheters. OMA infused ICV rapidly appeared in the systemic circulation and more effectively attenuated the systemic than the central pressor responses to Ang I. OMA administered orally (5, 25, 100 µmol/kg body weight) or IV (0.5, 1, 5, 25 µmol/kg body weight) completely abolished increases in blood pressure to IV Ang I up to 2 h after treatment. The pressor responses to ICV Ang I were not altered, indicating that systemically administered OMA does not cross the BBB. To study the effects of ACE and NEP inhibition in the brain on the recovery from ischaemic stroke, OMA was infused ICV over a 5-day period before and 24 h after the occlusion of the middle cerebral artery (MCAO) for 90 min. ICV application of OMA had no effect on infarction volume and marginally improved neurological outcome. We demonstrate for the first time that simultaneous inhibition of ACE and NEP in the brain tissue does not alter the recovery from ischaemic stroke.

Endothelial permeability in vitro and in vivo: protective actions of ANP and omapatrilat in experimental atherosclerosis.

Increased arterial endothelial cell permeability (ECP) is considered an initial step in atherosclerosis. Atrial natriuretic peptide (ANP) which is rapidly degraded by neprilysin (NEP) may reduce injury-induced endothelial cell leakiness. Omapatrilat represents a first in class of pharmacological agents which inhibits both NEP and angiotensin converting enzyme (ACE). We hypothesized that ANP prevents thrombin-induced increases of ECP in human aortic ECs (HAECs) and that omapatrilat would reduce aortic leakiness and atherogenesis and enhance ANP mediated vasorelaxation of isolated aortas. Thrombin induced ECP determined by I(125) albumin flux was assessed in HAECs with and without ANP pretreatment. Next we examined the effects of chronic oral administration of omapatrilat (12 mg/kg/day, n=13) or placebo (n=13) for 8 weeks on aortic leakiness, atherogenesis and ANP-mediated vasorelaxation in isolated aortas in a rabbit model of atherosclerosis produced by high cholesterol diet. In HAECs, thrombin-induced increases in ECP were prevented by ANP. Omapatrilat reduced the area of increased aortic leakiness determined by Evans-blue dye and area of atheroma formation assessed by Oil-Red staining compared to placebo. In isolated arterial rings, omapatrilat enhanced vasorelaxation to ANP compared to placebo with and without the endothelium. ANP prevents thrombin-induced increases in ECP in HAECs. Chronic oral administration of omapatrilat reduces aortic leakiness and atheroma formation with enhanced endothelial independent vasorelaxation to ANP. These studies support the therapeutic potential of dual inhibition of NEP and ACE in the prevention of increased arterial ECP and atherogenesis which may be linked to the ANP/cGMP system.

Combined neutral endopeptidase inhibitors.

INTRODUCTION: The renin-angiotensin-aldosterone system (RAAS) plays an important role in the pathophysiology of hypertension and heart failure. ACE inhibitors, angiotensin receptor II blockers (AT-II blockers) and aldosterone antagonists have been used to tackle the RAAS in the past but combined ACE and neutral endopeptidase (NEP) inhibitors have been shown to be more potent in reducing blood and especially pulse pressure in patients with hypertension. AREAS COVERED: Different NEP inhibitors have been tested but omapatrilat is the most widely studied in the setting of hypertension, heart failure and chronic angina. We have undertaken a PubMed search on NEP with a special focus on omapatrilat and its efficacy in hypertension and heart failure. The incidence of angioedema is more frequent in patients taking combined ACE and NEP inhibitors and this has prevented these medications from finding a widespread use. Combinations of NEP inhibitors and AT-II blockers are currently being studied and have been shown to reduce the blood pressure significantly. These medications have so far not been associated with angioedema and have a great potential to be safe and effective alternatives in the near future. EXPERT OPINION: NEP inhibitors were effective in the treatment of hypertension and heart failure but the relatively high incidence of angioedema stopped their widespread use. New hope has risen with the introduction of combined NEP inhibitors and AT-II blockers and early studies are encouraging.

Olanzapine (LY170053, 2-methyl-4-(4-methyl-1-piperazinyl)-10H-thieno[2,3-b][1,5] benzodiazepine), but not the novel atypical antipsychotic ST2472 (9-piperazin-1-ylpyrrolo[2,1-b][1,3]benzothiazepine), chronic administration induces weight gain, hyperphagia, and metabolic dysregulation in mice.

A mouse model of atypical antipsychotic-associated adverse effects was used to compare the liability to induce weight gain, food intake, and metabolic alterations after chronic olanzapine (OL; LY170053, 2-methyl-4-(4-methyl-1-piperazinyl)-10H-thieno-[2,3-b][1,5] benzodiazepine) and ST2472 (ST; 9-piperazin-1-ylpyrrolo[2,1-b][1,3]benzothiazepine) administration. By adding two equipotent doses (3 and 6 mg/kg) of either OL or ST to a high-sweet, high-fat (HS-HF) diet, mice were allowed to self-administer drugs up to 50 days. Body weight and food intake were evaluated daily. Locomotor activity was recorded over 48 h at two different time points. Dyslipidemia was measured by central visceral obesity. Blood serum levels of insulin (IN), glucose (Glu), triglycerides (TGs), nonesterified fatty acids (NEFAs), cholesterol (Ch), and ketone (Ke) bodies were quantified. OL treatment at 3 mg/kg enhanced body weight, whereas at the highest dose, the increase became evident only during the last 10 days of treatment. OL (3 mg/kg) increased HS-HF intake over time, whereas the highest dose reduced intake during the second 10 and final 10 days of administration. Both compounds induced nocturnal hypomotility at the highest dose. In contrast to ST, 3 mg/kg OL elevated serum levels of IN, Glu, TG, NEFA, Ch, and Ke, whereas 6 mg/kg OL elevated those of Glu, TG, and Ch. In contrast, ST did not affect weight gain, food intake, and metabolic markers. Given the similarities between OL-induced obesogenic effects and medical reports, this study further supports the view that ST may represent a new class of agents characterized by a low propensity to induce side effects with promising clinical safety.

Effect of bradykinin metabolism inhibitors on evoked hypotension in rats: rank efficacy of enzymes associated with bradykinin-mediated angioedema.

BACKGROUND AND PURPOSE: Inhibition of bradykinin metabolizing enzymes (BMEs) can cause acute angioedema, as demonstrated in a recent clinical trial in patients administered the antihypertensive, omapatrilat. However, the relative contribution of specific BMEs to this effect is unclear and confounded by the lack of a predictive pre-clinical model of angioedema. EXPERIMENTAL APPROACH: Rats were instrumented to record blood pressure and heart rate; inhibitors were infused for 35 min and bradykinin was infused during the last 5 min to elicit hypotension, as a functional marker of circulating bradykinin and relative angioedema risk. KEY RESULTS: In the presence of omapatrilat bradykinin produced dose-dependent hypotension, an effect abolished by B(2) blockade. In the presence of lisinopril (ACE inhibitor), but not candoxatril (NEP inhibitor) or apstatin (APP inhibitor), bradykinin also elicited hypotension. Lisinopril-mediated hypotension was unchanged with concomitant blockade of NEP or NEP/DPPIV (candoxatril+A-899301). However, hypotension was enhanced upon concomitant blockade of APP and further intensified in the presence of NEP inhibition to values not different from omapatrilat alone. CONCLUSIONS AND IMPLICATIONS: We demonstrated that bradykinin is degraded in vivo with an enzyme rank-efficacy of ACE>APP>>NEP or DPPIV. These results suggest the effects of omapatrilat are mediated by inhibition of three BMEs, ACE/APP/NEP. However, dual inhibition of ACE/NEP or ACE/NEP/DPPIV elicits no increased risk of angioedema compared to ACE inhibition alone. Thus, novel BME inhibitors must display no activity against APP to avoid angioedema risk due to high prevalence of ACE inhibitor therapy in patients with diabetes and cardiovascular disease.

Involvement of AMPA receptor phosphorylation in antidepressant actions with special reference to tianeptine.

Depression is associated with abnormal neuronal plasticity. AMPA receptors mediate transmission and plasticity at excitatory synapses in a manner which is positively regulated by phosphorylation at Ser831-GluR1, a CaMKII/PKC site, and Ser845-GluR1, a PKA site. Treatment with the selective serotonin (5-hydroxytryptamine; 5-HT) reuptake inhibitor fluoxetine increases P-Ser845-GluR1 but not P-Ser831-GluR1. Here, it was found that treatment with another antidepressant, tianeptine, increased P-Ser831-GluR1 in the frontal cortex and the CA3 region of hippocampus and P-Ser845-GluR1 in the CA3 region of hippocampus. A receptorome profile detected no affinity for tianeptine at any monaminergic receptors or transporters, confirming an atypical profile for this compound. Behavioural analyses showed that mice bearing point mutations at both Ser831- and Ser845-GluR1, treated with saline, exhibited increased latency to enter the centre of an open field and increased immobility in the tail-suspension test compared to their wild-type counterparts. Chronic tianeptine treatment increased open-field locomotion and reduced immobility in wild-type mice but not in phosphomutant GluR1 mice. P-Ser133-CREB was reduced in the CA3 region of hippocampus in phosphomutant mice, and tianeptine decreased P-Ser133-CREB in this region in wild-type, but not in phosphomutant, mice. Tianeptine increased P-Ser133-CREB in the CA1 region in wild-type mice but not in phosphomutant GluR1 mice. There were higher basal P-Ser133-CREB and c-fos levels in frontal and cingulate cortex in phosphomutant GluR1 mice; these changes in level were counteracted by tianeptine in a GluR1-independent manner. Using phosphorylation assays and phosphomutant GluR1 mice, this study provides evidence that AMPA receptor phosphorylation mediates certain explorative and antidepressant-like actions under basal conditions and following tianeptine treatment.

Neonatal dexamethasone and chronic tianeptine treatment inhibit ligature-induced periodontitis in adult rats.

OBJECTIVE: The responsiveness of the hypothalamic-pituitary-adrenal (HPA) axis has been found to play a significant role for susceptibility and resistance to periodontal disease. In the present study we have investigated the effects of two different treatment strategies, which have been found to down-regulate the HPA axis, on ligature-induced periodontitis. METHODS: In experiment 1, newborn rats were treated with the synthetic glucocorticoid hormone dexamethasone-21-phosphate, which permanently down-regulates HPA axis responsiveness. In experiment 2, adult rats were treated with the novel antidepressant drug tianeptine, which opposes the action of stress. Periodontitis was inflicted upon all rats. Just before decapitation the animals received gram-negative bacterial lipopolysaccharide (LPS) to induce a robust immune and HPA axis response. RESULTS: Compared to the saline-treated control rats, dexamethasone-treated rats had significantly less periodontal bone loss (p < 0.01), reduced expression of glucocorticoid receptors in the hippocampus (p < 0.001), lower corticosterone (p=0.01) and higher plasma levels of the cytokine tumor necrosis factor (TNF)-alpha (p < 0.05) after LPS challenge. Also the tianeptine-treated rats showed significantly reduced periodontal bone loss (p=0.01), enhanced plasma levels of TNF-alpha (p < 0.05), and transforming growth factor-1beta (p < 0.01), whereas no significant difference was found in corticosterone levels. CONCLUSION: An individual's responsiveness to danger signals, whether they are of immunological, chemical, or psychological origin, may be an important factor for explaining variability in susceptibility to periodontal disease. The results may provide new insight into the mechanisms of periodontal disease development, and open new vistas for disease prevention.

Renoprotective effect of long-term combined treatment with adrenomedullin and omapatrilat in hypertensive rats.

BACKGROUND: Previous studies demonstrated that adrenomedullin (AM) is metabolized by neutral endopeptidases and that the renal effect of AM is augmented by the inhibition of neutral endopeptidases. We have recently shown that the long-term administration of AM has renoprotective effects. OBJECT: This study assessed the chronic renoprotective effects of AM combined with a vasopeptidase inhibitor in hypertensive rats and attempted to elucidate the mechanism involved. METHODS: We studied the following four groups: control Dahl salt-resistant (DR) rats, untreated Dahl salt-sensitive (DS) rats, omapatrilat (35 mg/kg per day)-treated DS rats; and human AM (500 ng/h) plus omapatrilat-treated DS rats. After 7 weeks' treatment, blood pressure, renal function, neurohumoral factors, gene expression levels, and histological findings were examined. RESULTS: DS rats were characterized by increased blood pressure, decreased renal function, abnormal histological findings, and increased gene expression of collagen I and III, transforming growth factor beta (TGF-beta), and NADPH oxidase subunits (p40phox, p47phox, and gp91phox) in the renal cortex compared with DR rats. Compared with DS rats, omapatrilat significantly decreased systolic blood pressure (-26 mmHg), improved renal function, histological findings, and messenger RNA expression levels of collagen I, collagen III, and TGF-beta. Combined treatment with omapatrilat and AM further improved renal function, histological findings, and mRNA expression levels of collagen I, collagen III, and TGF-beta, without a further reduction in blood pressure. Only combined treatment decreased mRNA levels of p40phox, p47phox, and gp91phox. There were no differences in plasma AM or atrial natriuretic peptide levels among three DS groups. CONCLUSION: Our results suggest that combined treatment with omapatrilat and AM provides additional renoprotective effects independent of blood pressure-lowering activity partly via inhibition of gene expressions of oxidative stress and extracellular matrix.

Antianginal efficacy of omapatrilat in patients with chronic angina pectoris.

Angiotensin-converting enzyme inhibition is not an effective antianginal therapy. Experimental data suggest that broader vasopeptidase inhibition may decrease the magnitude of demand-induced myocardial ischemia. A randomized, double-blind, placebo controlled parallel study evaluated omapatrilat, an inhibitor of angiotensin-converting enzyme and neutral endopeptidase. The primary objective was to compare maximum duration of exercise at peak plasma concentrations. Exercise treadmill studies were performed in 348 patients who had chronic angina at baseline and after 4 weeks of therapy with 80 mg/day omapatrilat or placebo. Safety data were collected and reported for all patients. Treadmill exercise duration at peak was significantly prolonged in the omapatrilat group compared with the placebo group (76.6 +/- 84.2 vs 28.7 +/- 82.2 seconds difference from baseline, p <0.001). Similar statistically significant increases were seen in time to onset of level III/IV angina and time to onset of >/=0.1-mV ST-segment depression (p <0.001). The significant improvements in exercise duration and measurements of myocardial ischemia were not sustained 20 to 28 hours after dosing. Omapatrilat was generally well tolerated in this predominantly normotensive population. The incidence of serious adverse events was 5.2% in the 2 groups. Thus, omapatrilat, an investigational vasopeptidase inhibitor, is effective in prolonging exercise duration and parameters of demand-induced myocardial ischemia in patients who have chronic angina at peak concentrations. The data confirm the proof of principle that broader vasopeptidase inhibition beyond angiotensin-converting enzyme inhibition is required to alleviate symptoms of chronic angina.

[A role of depression in chronic dorsalgia: approaches to therapeutic correction]. / Rol' depressii v khronizatsii dorsalgii: podkhody k terapevticheskoi korrektsii.

An impact of depression on general clinical picture was studied in 20 patients with chronic dorsalgia, who were treated with coaxil. Along with complaints to prolonged back pains, patients featured by high depression and anxiety, sleep disturbances, autonomic dysfunction and marked decrease of quality of life. Psychometric tests revealed a presence of depressive symptoms in 90% of the cases. All patients were treated with coaxil in dosage 12.5 mg 3 times daily during 6 weeks. The treatment allowed a reduction of depression and anxiety symptoms, along with muscle dysfunction and pain syndrome. Positive dynamics of autonomic dysfunction, sleep disturbances and quality of life was observed already at the initial treatment stage. The results of the study confirm the fact that depression develops in patients with chronic dorsalgia, influencing negatively on the course of pain syndrome. Coaxil was shown to have high efficacy and safety in the treatment of depression caused by chronic back pain and positively influence on the main syndrome.

Chronic administration of tianeptine balances lipopolysaccharide-induced expression of cytokines in the spleen and hypothalamus of rats.

The antidepressant tianeptine has been shown to protect the hippocampus against the deleterious consequences of stress and to attenuate the behavioral and neuroendocrine effects of the cytokine inducer lipopolysaccharide (LPS). Since sickness symptoms are linked to peripheral and brain production of cytokines and pro-inflammatory cytokines can promote neurotoxicity, the present study was undertaken to test the possibility that tianeptine attenuates production of pro-inflammatory cytokines. This hypothesis has been tested by studying the effects of a chronic intraperitoneal (i.p.) administration of tianeptine (10 mg/kg twice a day for 21 days) to rats on the induction by LPS (250 microg/kg, i.p.) of the production of pro- and anti-inflammatory cytokines, at the periphery (spleen, pituitary) and in the brain (hypothalamus, hippocampus). The expression of mRNAs coding for IL-1 beta, TNF-alpha, IL-6 or IL-10 (RT-PCR) and plasma levels of IL-1 beta, TNF-alpha and IL-10 (ELISA) were measured at various time intervals following LPS. Chronic tianeptine treatment attenuated LPS-induced expression of TNF-alpha in the spleen as well as plasma levels of this cytokine and altered the central balance between pro- and anti-inflammatory cytokines (IL-1 beta/IL-10). These results open new vistas in the pharmacological activity of tianeptine and provide further insights on the possible mechanisms of action involved in its neuroprotective properties.

Cardiorenal protective effects of vasopeptidase inhibition with omapatrilat in hypertensive transgenic (mREN-2)27 rats.

Vasopeptidase inhibitors simultaneously inhibit both angiotensin-converting enzyme (ACE) and neutral endopeptidase (NEP). The aim of this study was to determine the cardiorenal effects of the vasopeptidase inhibitor omapatrilat in the transgenic m(Ren-2)27 rat which exhibits fulminant hypertension and severe organ pathology. At 6 weeks of age, male Ren-2 rats were randomized to receive no treatment (N = 10), the ACE inhibitor fosinopril 10 mg/kg/day (N = 10), or omapatrilat 10 mg/kg/day (N = 10) or 40 mg/kg/day (N = 10) by daily gavage for 24 weeks. Various cardiorenal functional and structural parameters were assessed. Compared to controls, all treatment groups reduced hypertension in control Ren-2 rats, with both doses of omapatrilat reducing systolic blood pressure significantly more than fosinopril (control, 178 +/- 3 mmHg; fosinopril 10 mg/kg/day, 130 +/- 4 mmHg; omapatrilat 10 mg/kg/day, 110 +/- 3 mmHg; omapatrilat 40 mg/kg/day, 91 +/- 3 mmHg). Omapatrilat dose-dependently reduced cardiac hypertrophy, caused a greater inhibition of renal ACE than fosinopril, and was the only treatment to inhibit renal NEP. Attenuation of albuminuria, glomerulosclerosis and cardiorenal fibrosis occurred to a similar degree with omapatrilat and fosinopril. Omapatrilat confers cardiorenal protection in the hypertensive Ren-2 rat. Although inhibition of tissue NEP may contribute to the superior blood pressure reduction by omapatrilat, overall, the results are consistent with the central role that angiotensin II plays in renal and cardiac fibrosis in this model of hypertension.

Low-dose combination therapy with temocapril and losartan reduces proteinuria in normotensive patients with immunoglobulin a nephropathy.

This study investigates the ability of low doses of angiotensin-converting-enzyme inhibitors, in combination with angiotensin II receptor blockers, to exert antiproteinuric effects in normotensive and proteinuric outpatients with immunoglobulin A (IgA) nephropathy confirmed by biopsy. We performed a prospective, randomized, 6-month study of the effects of temocapril 1 mg (n=10), losartan 12.5 mg (n=10), and both (n=11) on mild-to-moderate proteinuria 0.76+/-0.35 g/day (range, 0.4 to 1.6 g/day) and renal function. The study subjects comprised 31 normotensive and proteinuric outpatients with IgA nephropathy accompanied by normal, or mild-to-moderately reduced but stable renal function (glomerular filtration rate>50 ml/min) without steroid or immunosuppressive therapy. We prospectively evaluated blood pressure, proteinuria, renal function and biochemical parameters before and after 6 months of therapy. The combination therapy significantly reduced proteinuria (63.2%) compared with either temocapril or losartan alone (41.3% and 36.6%, respectively, p=0.04 and 0.01, respectively). Blood pressure was most decreased in the group that received combination therapy. The reduced proteinuria did not correlate with reduced systolic or diastolic blood pressure or mean arterial pressure in any of the groups. The glomerular filtration rate fell during the first 3 months of combined therapy, but became reversible after a further 3 months of therapy. The combination significantly decreased angiotensin II (p <0.01), and this decrease was greater than that by either drug alone. In conclusion, the effectiveness of the combined therapy may have been at least partly due to the greater inhibition of the action of angiotensin II in patients with IgA nephropathy. This strategy apparently reduced mild-to-moderate proteinuria in patients with normotensive IgA nephropathy.

Should increasing the dose or adding an AT1 receptor blocker follow a relatively low dose of ACE inhibitor initiated in acute myocardial infarction?

OBJECTIVE: Based on currently available clinical evidence, we should use high-dose angiotensin converting enzyme inhibitor (ACE-I) for patients with acute myocardial infarction (MI), initiating it at incremental doses to avoid excessive hypotension. Recent animal studies with acute MI models failed to demonstrate the superiority of the combination therapy of ACE-I and angiotensin receptor blocker (ARB) to high-dose ACE-I treatment with comparable blood pressure reductions, which however might be attributed to the initiation of the targeted doses from the beginning. The aim of this study was to compare the effect of increasing the dose of ACE-I with that of adding ARB following a relatively low dose of ACE-I on the survival and left ventricular (LV) remodeling after MI. METHODS: Rats underwent left coronary artery ligation and were treated with either ACE-I temocapril (5 mg/kg/day) or vehicle for 2 weeks, which was initiated 3 days after the surgery. The rats treated with temocapril were further randomly assigned to receive either high-dose temocapril (10 mg/kg/day) or combination therapy (temocapril 5 mg/kg/day+olmesartan 2.5 mg/kg/day), which was continued for another 6 weeks. RESULTS: Both treatments similarly reduced the blood pressure, improved survival and ameliorated LV enlargement. In contrast, several parameters of LV function were significantly ameliorated only by the high-dose ACE-I but not by the combination therapy. CONCLUSIONS: After the initiation of a relatively low dose of ACE-I in acute MI, increasing the dose of ACE-I or adding ARB may equally improve survival and LV remodeling in the setting of an equal hypotensive effect. Further study with a longer treatment protocol is required to determine whether the several favorable effects on LV function elicited only by the high-dose ACE-I treatment provide further beneficial effects on survival and LV remodeling compared with the combination therapy.

Chronic treatment with the antidepressant tianeptine attenuates lipopolysaccharide-induced Fos expression in the rat paraventricular nucleus and HPA axis activation.

The antidepressant tianeptine has been shown to decrease the response of the hypothalamic-pituitary-adrenal (HPA) axis to stress and to attenuate the behavioral effects of the cytokine inducer, lipopolysaccharide (LPS). Since LPS also activates the HPA axis, the objective of this study was to assess the effects of tianeptine on the HPA axis activation and Fos expression induced by intraperitoneal (i.p.) administration of LPS (30 and 250 microg/kg respectively). Chronic, but not acute, tianeptine treatment (10 mg/kg twice a day for 15 days, i.p.) attenuated LPS-induced increase of plasma ACTH and corticosterone in rats bearing an indwelling catheter in the jugular vein and Fos immunoreactivity in the paraventricular nucleus (PVN). These results open new vistas on the pharmacological activity of tianeptine and provide further insights on the action mechanisms of antidepressants in clinics.

Comparative biotransformation of radiolabeled [(14)C]omapatrilat and stable-labeled [(13)C(2)]omapatrilat after oral administration to rats, dogs, and humans.

Omapatrilat, a novel vasopeptidase inhibitor, is under development for the treatment of hypertension and congestive heart failure. This study describes the comparative biotransformation of radiolabeled [(14)C]- and stable-labeled [(13)C(2)]omapatrilat after administration of single oral doses to rats, dogs, and humans. The metabolites were identified by a combination of methods including reduction, hydrolysis, and comparison of high performance liquid chromatography retention times with those of the synthetic standards. Urinary metabolites were further characterized by liquid chromatography tandem mass spectrometry analysis. Prominent metabolites identified in human plasma, which were also present in rat and dog plasma, were S-methyl omapatrilat and S-2-thiomethyl-3-phenylpropionic acid. Omapatrilat accounted for only a small portion of the extractable radioactivity in plasma in all three species. A portion of the plasma radioactivity was unextractable in all three species (27-53%). The majority of unextractable radioactivity in plasma was characterized after dithiothreitol reduction to be omapatrilat and (S)-2-thio-3-phenylpropionic acid, both apparently bound to plasma proteins by reversible disulfide bonds. The major human urinary metabolites were the amine hydrolysis product, diasteromeric sulfoxide of (S)-2-thiomethyl-3-phenylpropionic acid, acyl glucuronide of S-methyl omapatrilat, and S-methyl omapatrilat. The minor metabolites were acyl glucuronide of (S)-2-thiomethyl-3-phenylpropionic acid, L-cysteine mixed disulfide of omapatrilat, diastereomers of S-methyl sulfoxide of omapatrilat, and S-methyl omapatrilat ring sulfoxide. The metabolic profiles of dog and human urine were qualitatively similar whereas rat urine showed only metabolites arising from hydrolysis of omapatrilat. Unchanged omapatrilat was not found in rat, dog, or human urine samples indicating extensive metabolism in vivo.