scholarly journals Involvement of β3-Adrenoceptor in Altered β-Adrenergic Response in Senescent Heart

2008 ◽  
Vol 109 (6) ◽  
pp. 1045-1053 ◽  
Author(s):  
Aurélie Birenbaum ◽  
Angela Tesse ◽  
Xavier Loyer ◽  
Pierre Michelet ◽  
Ramaroson Andriantsitohaina ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Electron Paramagnetic Resonance ◽  
Positive Inotropic Effect ◽  
Inotropic Effect ◽  
Paramagnetic Resonance ◽  
Beta Adrenergic ◽  
Adrenergic Response ◽  
Electron Paramagnetic

Background In senescent heart, beta-adrenergic response is altered in parallel with beta1- and beta2-adrenoceptor down-regulation. A negative inotropic effect of beta3-adrenoceptor could be involved. In this study, the authors tested the hypothesis that beta3-adrenoceptor plays a role in beta-adrenergic dysfunction in senescent heart. Methods beta-Adrenergic responses were investigated in vivo (echocardiography-dobutamine, electron paramagnetic resonance) and in vitro (isolated left ventricular papillary muscle, electron paramagnetic resonance) in young adult (3-month-old) and senescent (24-month-old) rats. Nitric oxide synthase (NOS) immunolabeling (confocal microscopy), nitric oxide production (electron paramagnetic resonance) and beta-adrenoceptor Western blots were performed in vitro. Data are mean percentages of baseline +/- SD. Results An impaired positive inotropic effect (isoproterenol) was confirmed in senescent hearts in vivo (117 +/- 23 vs. 162 +/- 16%; P < 0.05) and in vitro (127 +/- 10 vs. 179 +/- 15%; P < 0.05). In the young adult group, the positive inotropic effect was not significantly modified by the nonselective NOS inhibitor N-nitro-L-arginine methylester (L-NAME; 183 +/- 19%), the selective NOS1 inhibitor vinyl-L-N-5(1-imino-3-butenyl)-L-ornithine (L-VNIO; 172 +/- 13%), or the selective NOS2 inhibitor 1400W (183 +/- 19%). In the senescent group, in parallel with beta3-adrenoceptor up-regulation and increased nitric oxide production, the positive inotropic effect was partially restored by L-NAME (151 +/- 8%; P < 0.05) and L-VNIO (149 +/- 7%; P < 0.05) but not by 1400W (132 +/- 11%; not significant). The positive inotropic effect induced by dibutyryl-cyclic adenosine monophosphate was decreased in the senescent group with the specific beta3-adrenoceptor agonist BRL 37344 (167 +/- 10 vs. 142 +/- 10%; P < 0.05). NOS1 and NOS2 were significantly up-regulated in the senescent rat. Conclusions In senescent cardiomyopathy, beta3-adrenoceptor overexpression plays an important role in the altered beta-adrenergic response via induction of NOS1-nitric oxide.

ДИНИТРОЗИЛЬНЫЕ КОМПЛЕКСЫ ЖЕЛЕЗА C ТИОЛСОДЕРЖАЩИМИ ЛИГАНДАМИ ПРЕДСТАВЛЕНЫ В ЖИВЫХ ОРГАНИЗМАХ В ОСНОВНОМ ИХ БИЯДЕРНОЙ ФОРМОЙ

2020 ◽  
Vol 65 (6) ◽  
pp. 1142-1153
Author(s):  
В.Д. Микоян ◽  
◽  
Е.Н. Бургова ◽  
Р.Р. Бородулин ◽  
А.Ф. Ванин ◽  
...  
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Sodium Nitrite ◽  
Iron Complexes ◽  
Paramagnetic Resonance ◽  
First Case ◽  
Dinitrosyl Iron ◽  
Electron Paramagnetic ◽  
Dinitrosyl Complexes

The number of mononitrosyl iron complexes with diethyldithiocarbamate, formed in the liver of mice in vivo and in vitro after intraperitoneal injection of binuclear dinitrosyl iron complexes with N-acetyl-L-cysteine or glutathione, S-nitrosoglutathione, sodium nitrite or the vasodilating drug Isoket® was assessed by electron paramagnetic resonance (EPR). The number of the said complexes, in contrast to the complexes, formed after nitrite or Isoket administration, the level of which sharply increased after treatment of liver preparations with a strong reducing agent - dithionite, did not change in the presence of dithionite. It was concluded that, in the first case, EPR-detectable mononitrosyl iron complexes with diethyldithiocarbamate in the absence and presence of dithionite appeared as a result of the reaction of NO formed from nitrite with Fe2+-dieth- yldithiocarbamate and Fe3+-diethyldithiocarbamate complexes, respectively. In the second case, mononitrosyl iron complexes with diethyldithiocarbamate appeared as a result of the transition of iron-mononitosyl fragments from ready-made iron-dinitrosyl groups of binuclear dinitrosyl complexes, which is three to four times higher than the content of the mononuclear form of these complexes in the tissue...

scholarly journals In Vivo Formation of Electron Paramagnetic Resonance-Detectable Nitric Oxide and of Nitrotyrosine Is Not Impaired during Murine Leishmaniasis

1998 ◽  
Vol 66 (2) ◽  
pp. 807-814 ◽  
Author(s):  
Selma Giorgio ◽  
Edlaine Linares ◽  
Harry Ischiropoulos ◽  
Fernando José Von Zuben ◽  
Aureo Yamada ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Electron Paramagnetic Resonance ◽  
Parasite Burden ◽  
Immunohistochemical Analysis ◽  
Mouse Strains ◽  
No Production ◽  
Cutaneous Lesions ◽  
Paramagnetic Resonance ◽  
Electron Paramagnetic

ABSTRACT Recent studies have provided evidence for a dual role of nitric oxide (NO) during murine leishmaniasis. To explore this problem, we monitored the formation of NO and its derived oxidants during the course of Leishmania amazonensis infection in tissues of susceptible (BALB/c) and relatively resistant (C57BL/6) mice. NO production was detected directly by low-temperature electron paramagnetic resonance spectra of animal tissues. Both mouse strains presented detectable levels of hemoglobin nitrosyl (HbNO) complexes and of heme nitrosyl and iron-dithiol-dinitrosyl complexes in the blood and footpad lesions, respectively. Estimation of the nitrosyl complex levels demonstrated that most of the NO is synthesized in the footpad lesions. In agreement, immunohistochemical analysis of the lesions demonstrated the presence of nitrotyrosine in proteins of macrophage vacuoles and parasites. Since macrophages lack myeloperoxidase, peroxynitrite is likely to be the nitrating NO metabolite produced during the infection. The levels of HbNO complexes in the blood reflected changes occurring during the infection such as those in parasite burden and lesion size. The maximum levels of HbNO complexes detected in the blood of susceptible mice were higher than those of C57BL/6 mice but occurred at late stages of infection and were accompanied by the presence of bacteria in the cutaneous lesions. The results indicate that the local production of NO is an important mechanism for the elimination of parasites if it occurs before the parasite burden becomes too high. From then on, elevated production of NO and derived oxidants aggravates the inflammatory process with the occurrence of a hypoxic environment that may favor secondary infections.

scholarly journals Altered Contractile Response due to Increased β3-Adrenoceptor Stimulation in Diabetic Cardiomyopathy

2007 ◽  
Vol 107 (3) ◽  
pp. 452-460 ◽  
Author(s):  
Julien Amour ◽  
Xavier Loyer ◽  
Morgan Le Guen ◽  
Nejma Mabrouk ◽  
Jean-Stéphane David ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Diabetic Cardiomyopathy ◽  
Positive Inotropic Effect ◽  
Left Ventricular ◽  
Inotropic Effect ◽  
Inotropic Response ◽  
Beta Adrenoceptor ◽  
Adrenoceptor Antagonist

Background In the diabetic heart, the positive inotropic response to beta-adrenoceptor stimulation is altered and beta1 and beta2 adrenoceptors are down-regulated, whereas beta3 adrenoceptor is up-regulated. In heart failure, beta3-adrenoceptor stimulation induces a negative inotropic effect that results from endothelial nitric oxide synthase (NOS3)-derived nitric oxide production. The objective of our study was to investigate the role of beta3-adrenoceptor in diabetic cardiomyopathy. Methods beta-Adrenergic responses were investigated in vivo (dobutamine echocardiography) and in vitro (left ventricular papillary muscle) in healthy and streptozotocin-induced diabetic rats. The effect of beta3-adrenoceptor inhibition on the inotropic response was studied in vitro. Immunoblots and NOS activities were performed in heart homogenates (electron paramagnetic resonance) and isolated cardiomyocytes. Data are mean percentage of baseline +/- SD. Results The impaired positive inotropic effect was confirmed in diabetes both in vivo (121 +/- 15% vs. 160 +/- 16%; P < 0.05) and in vitro (112 +/- 5% vs. 179 +/- 15%; P < 0.05). In healthy rat, the positive inotropic effect was not significantly modified in presence of beta3-adrenoceptor antagonist (174 +/- 20%), nonselective NOS inhibitor (N -nitro-l-arginine methylester [l-NAME]; 183 +/- 19%), or selective NOS1 inhibitor (vinyl-l-N-5-(1-imino-3-butenyl)-l-ornithine [l-VNIO]; 172 +/- 13%). In diabetes, in parallel with the increase in beta3-adrenoceptor protein expression, the positive inotropic effect was partially restored by beta3-adrenoceptor antagonist (137 +/- 8%; P < 0.05), l-NAME (133 +/- 11%; P < 0.05), or l-VNIO (130 +/- 13%; P < 0.05). Nitric oxide was exclusively produced by NOS1 within diabetic cardiomyocytes. NOS2 and NOS3 proteins were undetectable. Conclusions beta3-Adrenoceptor is involved in altered positive inotropic response to beta-adrenoceptor stimulation in diabetic cardiomyopathy. This effect is mediated by NOS1-derived nitric oxide in diabetic cardiomyocyte.

Electron paramagnetic resonance (EPR) spectroscopy: Food, biomedical and pharmaceutical analysis

2020 ◽  
Vol 9 (3-4) ◽  
pp. 165-182
Author(s):  
Siavash Iravani ◽  
Ghazaleh Jamalipour Soufi
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Drug Release ◽  
Epr Spectroscopy ◽  
Pharmaceutical Analysis ◽  
Direct Detection ◽  
Spectroscopic Method ◽  
Paramagnetic Resonance ◽  
Electron Paramagnetic

Electron paramagnetic resonance (EPR) spectroscopy can be applied as an effective and non-invasive spectroscopic method for analyzing samples with unpaired electrons. EPR is suitable for the quantification of radical species, assessment of redox chemical reaction mechanisms in foods, evaluation of the antioxidant capacity of food, as well as for the analysis of food quality, stability, and shelf life. It can be employed for evaluating and monitoring the drug release processes, in vitro and in vivo. EPR can be employed for the direct detection of free radical metabolites, and the evaluation of drug release mechanisms from biodegradable polymers; it can be employed for analyzing the drug antioxidant effects. Additionally, spatial resolution can be achieved through EPR-imaging. EPR spectroscopy and imaging have shown diverse applications in food, biomedical and pharmaceutical fields, and also more applications are predictable to emerge in the future. This review highlights recent advances and important challenges related to the application of EPR in food, biomedical and pharmaceutical analysis and assessment.

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