Modification of cardiac β-adrenoceptor mechanisms by H2O2
| العنوان: | Modification of cardiac β-adrenoceptor mechanisms by H2O2 |
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| المؤلفون: | Rashi Jindal, Heinz Rupp, Naranjan S. Dhalla, Sujata Persad, Jugpal S. Arneja |
| المصدر: | Scopus-Elsevier |
| بيانات النشر: | American Physiological Society, 1998. |
| سنة النشر: | 1998 |
| مصطلحات موضوعية: | medicine.medical_specialty, Physiology, G protein, chemistry.chemical_element, Biology, medicine.disease_cause, Oxygen, Adenylyl cyclase, chemistry.chemical_compound, GTP-Binding Proteins, Physiology (medical), Internal medicine, Receptors, Adrenergic, beta, medicine, Animals, Mannitol, chemistry.chemical_classification, Adenosine Diphosphate Ribose, Guanylyl Imidodiphosphate, Myocardium, Cell Membrane, Colforsin, ADCY9, Isoproterenol, Heart, Hydrogen Peroxide, Adrenergic beta-Agonists, Catalase, Rats, Kinetics, Oxidative Stress, Enzyme, Endocrinology, chemistry, Circulatory system, Sodium Fluoride, Signal transduction, Cardiology and Cardiovascular Medicine, Oxidative stress, Adenylyl Cyclases |
| الوصف: | From the role of oxidative stress in cardiac dysfunction, we investigated the effect of H2O2, an activated species of oxygen, on β-adrenoceptors, G proteins, and adenylyl cyclase activities. Rat heart membranes were incubated with different concentrations of H2O2before the biochemical parameters were measured. Both the affinity and density of β1-adrenoceptors were decreased, whereas the density of the β2-adrenoceptors was decreased and the affinity was increased by 1 mM H2O2. Time- and concentration-dependent biphasic changes in adenylyl cyclase activities in the absence or presence of isoproterenol were observed when membranes were incubated with H2O2; however, activation of the enzyme by isoproterenol was increased or unaltered. The adenylyl cyclase activities in the absence or presence of forskolin, NaF, and Gpp(NH)p were depressed by H2O2. Catalase alone or in combination with mannitol was able to significantly decrease the magnitude of alterations due to H2O2. The cholera toxin-stimulated adenylyl cyclase activity and ADP ribose labeling of Gsproteins were decreased by treatment with 1 mM H2O2, whereas Giprotein activities, as reflected by pertussis toxin-stimulation of adenylyl cyclase and ADP ribosylation, were unaltered. The Gsand Giprotein immunoreactivities, estimated by labeling with respective antibodies, indicate a decrease in binding to the 45-kDa band of Gsprotein, whereas no change in the binding of antibodies to the 52-kDa band of Gsprotein or the 40-kDa subunit of Giprotein was evident when the membranes were treated with 1 mM H2O2. These results suggest that H2O2in high concentrations may attenuate the β-adrenoceptor-linked signal transduction in the heart by changing the functions of Gsproteins and the catalytic subunit of the adenylyl cyclase enzyme. |
| تدمد: | 1522-1539 0363-6135 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::4b2b6bb9e074de77f1614014aac0515f https://doi.org/10.1152/ajpheart.1998.274.2.h416 |
| رقم الأكسشن: | edsair.doi.dedup.....4b2b6bb9e074de77f1614014aac0515f |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 15221539 03636135 |
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