temocapril-hydrochloride and olmesartan

Liver-type fatty acid-binding protein (L-FABP) is a clinical biomarker of tubulointerstitial damage, which plays an essential role in the progression of chronic kidney disease (CKD), including immunoglobin A (IgA) nephropathy. The effect of combination therapy with the angiotensin receptor blocker (ARB) and the angiotensin-converting enzyme inhibitor (ACEI) on CKD has not been elucidated.. Twenty-four normotensive patients with IgA nephropathy were randomly assigned to receive olmesartan 10 mg/day, temocapril 2 mg/day, or combination therapy with both drugs. Urinary levels of L-FABP as well as 8-hydroxydeoxyguanosine (8-OHdG) and protein excretion were measured before and after 3 months of treatment. The chronicity index and activity index were also assessed by histopathologic findings.. Urinary levels of L-FABP and 8-OHdG were higher in patients with IgA nephropathy than in age-matched and sex-matched healthy controls (122.5 +/- 25.5 v 6.4 +/- 3.8 mug/g.creatinine, P < .001; and 22.6 +/- 4.4 v 4.8 +/- 1.4 ng/mg.creatinine, P < .01, respectively). Urinary levels of L-FABP were correlated with those of 8-OHdG (baseline, P = .0001; after 3 months, P = .008) and the severity of proteinuria (baseline, P = .0015; after 3 months, P = .0001). The percent reductions in urinary levels of L-FABP and 8-OHdG, protein excretion, and activity index after 3 months were greater in the combination therapy group, compared with each monotherapy group of olmesartan (P < .05) and temocapril (P < .05).. The data suggest that a combination therapy of ARB plus ACEI has a greater beneficial effect on renal injury compared with monotherapy using ARB or ACEI in normotensive patients with IgA nephropathy.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Angiotensin II Type 1 Receptor Blockers; Angiotensin-Converting Enzyme Inhibitors; Blood Pressure; Deoxyguanosine; Double-Blind Method; Drug Therapy, Combination; Fatty Acid-Binding Proteins; Female; Glomerulonephritis, IGA; Heart Rate; Humans; Imidazoles; Male; Proteinuria; Tetrazoles; Thiazepines

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.

Topics: Angiotensin I; Angiotensin II; Angiotensin II Type 1 Receptor Blockers; Angiotensin-Converting Enzyme Inhibitors; Animals; Antihypertensive Agents; Blood Pressure; Hypertension; Imidazoles; Kidney; Male; Peptidyl-Dipeptidase A; Rats; Rats, Sprague-Dawley; Renin-Angiotensin System; Tetrazoles; Thiazepines

We investigated the impact of olmesartan and temocapril on pancreatic islet beta-cells during the development of diabetes mellitus using Otsuka-Long-Evans-Tokushima Fatty (OLETF) rats. Four-week-old male OLETF rats were fed standard chow (untreated:n5), or chow containing either 0.005% olmesartan(n5) or 0.01% temocapril (n5) until being sacrificed at 35 weeks of age. Pancreas sections were double-stained with anti-insulin and anti-glucagon antibodies. The percent areas of beta-cells, alpha-cells and non-alpha-non-beta-cells were compared among groups. In untreated OLETF rats, the fasting plasma glucose (FPG) level was elevated at the 18th week and remained elevated until the 35th week. On the other hand, no significant elevation in FPG levels was observed in olmesartan- or temocapril-treated rats. Pancreatic islets from olmesartan-treated rats were significantly smaller in size as compared with those from untreated OLETF rats. Furthermore, the average area occupied by beta-cells as a fraction of the total area of an individual islet was significantly higher in olmesartan- or temocapril-treated rats than that in untreated OLETF rats. Olmesartan and temocapril both prevented the development of hyperglycemia, possibly through the prevention of islet beta-cell loss in spontaneously diabetic OLETF rats.

Topics: Angiotensin II Type 1 Receptor Blockers; Angiotensin-Converting Enzyme Inhibitors; Animals; C-Peptide; Fructosamine; Hyperglycemia; Imidazoles; Insulin; Insulin-Secreting Cells; Male; Rats; Rats, Inbred OLETF; Receptor, Angiotensin, Type 1; Tetrazoles; Thiazepines

The role of the renin-angiotensin system in oxidative stress-induced apoptosis of endothelial cells (ECs) was investigated using a rat model and cultured ECs. EC apoptosis was induced by 5-minute intra-arterial treatment of a rat carotid artery with 0.01 mmol/L H2O2 and was evaluated at 24 hours by chromatin staining of en face specimens with Hoechst 33342. Although activity of angiotensin-converting enzyme in arterial homogenates was not increased, administration of an angiotensin-converting enzyme inhibitor temocapril for 3 days before H2O2 treatment inhibited EC apoptosis, followed by reduced neointimal formation 2 weeks later. Also, an angiotensin II type 1 (AT1) receptor blocker (olmesartan) inhibited EC apoptosis, whereas angiotensin II administration accelerated apoptosis independently of blood pressure. Next, cultured ECs derived from a bovine carotid artery were treated with H2O2 to induce apoptosis, as evaluated by DNA fragmentation. Combination of angiotensin II and H2O2 dose-dependently increased EC apoptosis and 8-isoprostane formation, a marker of oxidative stress. Conversely, temocapril and olmesartan reduced apoptosis and 8-isoprostane formation induced by H2O2, suggesting that endogenous angiotensin II interacts with H2O2 to elevate oxidative stress levels and EC apoptosis. Neither an AT2 receptor blocker, PD123319, affected H2O2-induced apoptosis, nor a NO synthase inhibitor, NG-nitro-L-arginine methyl ester, influenced the effect of temocapril on apoptosis in cell culture experiments. These results suggest that AT1 receptor signaling augments EC apoptosis in the process of oxidative stress-induced vascular injury.

Topics: Angiotensin II Type 1 Receptor Blockers; Animals; Apoptosis; Carotid Arteries; Cells, Cultured; Dose-Response Relationship, Drug; Endothelial Cells; Enzyme Inhibitors; History, 20th Century; Hydrogen Peroxide; Imidazoles; Male; NG-Nitroarginine Methyl Ester; Oxidants; Oxidative Stress; Peptidyl-Dipeptidase A; Rats; Rats, Wistar; Renin-Angiotensin System; Tetrazoles; Thiazepines; Tunica Intima

Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II type 1 receptor blockers (ARBs) have potent antioxidant effects in addition to antihypertensive effects.. We investigated the ability of ACEIs and ARBs to enhance the superoxide scavenging ability of polymorphonuclear leukocytes (PMNLs) from type 2 diabetic patients (n = 32) and healthy subjects (n = 32). The scavenging ability (U/10(3) cells) of superoxide was measured by electron spin resonance. We used ascorbic acid as a positive control antioxidant and tested captopril, temocapril (an inactive form of ACEI), and temocaprilate (an active form of ACEI) as ACEIs, as well as RNH-6270 as an ARB.. Captopril, temocaprilate, and RNH-6270 showed dose-dependent enhancement in scavenging ability. The scavenging ability with captopril and temocaprilate was greater than with RNH-6270. The changes in scavenging ability induced by all of the drugs in diabetic patients were similar to the changes in healthy subjects. A high-glucose medium (400-800 mg/dL) greatly attenuated the drug-induced enhancement of scavenging ability.. We demonstrated that both ACEIs and ARBs enhance superoxide scavenging by PMNLs from type 2 diabetic patients and that a high-glucose environment markedly attenuates the ability of these drugs to augment superoxide scavenging.

Topics: Adult; Angiotensin II Type 1 Receptor Blockers; Angiotensin-Converting Enzyme Inhibitors; Antioxidants; Ascorbic Acid; Blood Glucose; Captopril; Diabetes Mellitus, Type 2; Female; Free Radical Scavengers; Humans; Imidazoles; In Vitro Techniques; Male; Middle Aged; Neutrophils; Superoxide Dismutase; Superoxides; Tetrazoles; Thiazepines

The current study was undertaken to evaluate the anti-proliferative effect of a novel angiotensin II type 1 (AT1) receptor antagonist, RNH-6270, on exaggerated growth of vascular smooth muscle cells (VSMC) from spontaneously hypertensive rats (SHR), in comparison with the effects of an angiotensin-converting enzyme (ACE) inhibitor. RNH-6270 and temocapril significantly inhibited basal DNA synthesis in VSMCs from SHRs in a dose-dependent manner, but not in cells from Wistar-Kyoto (WKY) rats. SHR-derived VSMC showed a hyperresponse of DNA synthesis to serum and angiotensin II compared with that of WKY rats-derived VSMC. RNH-6270 did not affect serum-stimulated DNA synthesis in VSMCs from both rat strains. RNH-6270 abolished angiotensin II-stimulated DNA synthesis in VSMC from both rat strains. RNH-6270 significantly inhibited proliferation of VSMC from both rat strains, but the ACE inhibitor temocapril did not exert such an effect. RNH-6270 decreased the specific binding of angiotensin II to VSMC in a competitive manner for angiotensin II receptors in both rat strains. RNH-6270 and temocapril significantly decreased the expression of growth factor mRNAs and proteins in VSMC from SHR, but not in cells from WKY rats. These results suggest that RNH-6270 is a potent AT1 receptor antagonist and has anti-proliferative effects on VSMCs from SHR, which was not seen with an ACE inhibitor. The growth inhibitory effect of RNH-6270 may be associated with the inhibition of growth factors via antagonism to AT1 receptors.

Topics: Angiotensin II; Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Animals; Blotting, Western; Cell Division; Cells, Cultured; Fibroblast Growth Factor 2; Imidazoles; Male; Muscle, Smooth, Vascular; Platelet-Derived Growth Factor; Radioligand Assay; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Receptor, Angiotensin, Type 1; Receptors, Angiotensin; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Tetrazoles; Thiazepines; Transforming Growth Factor beta; Transforming Growth Factor beta1