BACKGROUNDAliskiren is an oral renin inhibitor, which inhibits the first rate limiting step in the renin angiotensin aldosterone system. In this study, sympathetic nerve sprouting and the inducibility of ventricular fibrillation after aliskiren treatment in myocardial infarction were investigated.

METHODSMale Sprague Dawley rats after coronary artery ligation were randomly allocated to four groups: angiotensin converting enzyme inhibitor enalapril, angiotensin receptor blocker valsartan, β adrenergic receptor blocker carvedilol and rennin inhibitor aliskiren treatment for six weeks. Electrophysiological study, histological examination and Western blotting were performed.

RESULTSThe plasma norepinephrine level and sympathetic nerve innervation significantly increased in treated infarcted rats compared to untreated rats. Aliskiren treatment reduced the sympathetic nerve innervations after myocardial infarction. There is no significant difference in sympathetic nerve innervations after myocardial infarction among the enalapril, valsartan, carvediloand or aliskiren treated groups. Programmed electrical stimulation study showed that inducible ventricular arrhythmia was reduced, ventricular fibrillation threshold was increased and ventricular effective refractory period was prolonged in enalapril, valsartan, carvedilol and aliskiren treated infarcted rats compared to untreated infarcted rats. Cardiomyocytic apoptosis in infarcted region was significantly decreased in enalapril, valsartan, carvedilol and aliskiren treated infarcted rats.

CONCLUSIONSAliskiren ameliorated cardiomyocytic apoptosis, attenuated the sympathetic nerve innervations and reduced the vulnerability of ventricular arrhythmias after myocardial infarction. Enalapril, valsartan and carvedilol have similar effects as aliskiren on cardiomyocytic apoptosis, sympathetic nerve innervations and vulnerability of ventricular arrhythmias after myocardial infarction.

Amides ; pharmacology ; therapeutic use ; Animals ; Fumarates ; pharmacology ; therapeutic use ; Male ; Myocardial Infarction ; blood ; drug therapy ; Norepinephrine ; blood ; Rats ; Rats, Sprague-Dawley ; Renin ; antagonists & inhibitors ; Sympathetic Nervous System ; drug effects ; Tachycardia, Ventricular ; prevention & control

Fumaric acid esters (FAE), mainly dimethylfumarate (DMF), have been shown to be highly efficacious in the treatment of psoriasis. Among the potential side effects of FAE therapy, lymphocytopenia is sometimes observed. In order to address the question whether FAE may interfere with systems of the innate defense, the modulatory role of FAE on the generation of superoxide-anion by human monocytes and neutrophils was studied by measuring the reduction of cytochrome c. Various concentrations of DMF and its metabolite methylhydrogenfumarate (MHF) were used to observe their modulatory effect on superoxide-anion generation by monocytes and neutrophils in response to bacteria (S. aureus and E. coli) and candida (C. albicans). Dexamethasone (DXM, 1 x 10(-7) mol x L(-1)) was also studied at the same time. We found that DXM significantly inhibited superoxide-anion generation from monocytes in response to bacteria and C. albicans, whereas DMF and MHF (10-20 microg x mL(-1)) significantly increased the production of superoxide-anion in monocytes in response to the above mentioned bacteria. DXM, DMF and MHF did not affect superoxide-anion generation of neutrophils. Our data indicate that DMF and MHF enhance superoxide-anion generation in human monocytes as one of the important mechanisms of innate defense against microorganisms.
Candida albicans ; immunology ; Cells, Cultured ; Cytochrome c Group ; metabolism ; Dermatologic Agents ; pharmacology ; Dimethyl Fumarate ; Escherichia coli ; immunology ; Fumarates ; pharmacology ; Humans ; Phagocytes ; metabolism ; Staphylococcus aureus ; immunology ; Superoxides ; metabolism ; Zymosan ; immunology

BACKGROUND/AIMS: There has been controversy about the role of Toll-like receptor 2 (TLR2) in renal injury following ureteric obstruction. Although inhibition of the renin angiotensin system (RAS) reduces TLR2 expression in mice, the exact relationship between TLR2 and RAS is not known. The aim of this study was to determine whether the RAS modulates TLR2. METHODS: We used 8-week-old male wild type (WT) and TLR2-knockout (KO) mice on a C57Bl/6 background. Unilateral ureteral obstruction (UUO) was induced by complete ligation of the left ureter. Angiotensin (Ang) II (1,000 ng/kg/min) and the direct renin inhibitor aliskiren (25 mg/kg/day) were administrated to mice using an osmotic minipump. Molecular and histologic evaluations were performed. RESULTS: Ang II infusion increased mRNA expression of TLR2 in WT mouse kidneys (p < 0.05). The expression of renin mRNA in TLR2-KO UUO kidneys was significantly higher than that in WT UUO kidneys (p < 0.05). There were no differences in tissue injury score or mRNA expression of monocyte chemotactic protein 1 (MCP-1), osteopontin (OPN), or transforming growth factor beta (TGF-beta) between TLR2-KO UUO and WT UUO kidneys. However, aliskiren decreased the tissue injury score and mRNA expression of TLR2, MCP-1, OPN, and TGF-beta in WT UUO kidneys (p < 0.05). Aliskiren-treated TLR2-KO UUO kidneys showed less kidney injury than aliskiren-treated WT UUO kidneys. CONCLUSIONS: TLR2 deletion induced activation of the RAS in UUO kidneys. Moreover, inhibition of both RAS and TLR2 had an additive ameliorative effect on UUO injury of the kidney.
Amides/*pharmacology ; Angiotensin II/pharmacology ; Animals ; Disease Models, Animal ; Fibrosis ; Fumarates/*pharmacology ; Kidney/*drug effects/metabolism/pathology ; Male ; Mice, Inbred C57BL ; Mice, Knockout ; Nephritis, Interstitial/genetics/metabolism/pathology/*prevention & control ; RNA, Messenger/genetics/metabolism ; Renin/*antagonists & inhibitors/metabolism ; Renin-Angiotensin System/*drug effects ; Toll-Like Receptor 2/deficiency/drug effects/genetics/*metabolism ; Ureteral Obstruction/*drug therapy/genetics/metabolism/pathology