Calcium and zinc dyshomeostasis during isoproterenol-induced acute stressor state
| Autor: | Syamal K. Bhattacharya, Atta U. Shahbaz, Karl T. Weber, Patti L. Johnson, Ivan C. Gerling, Wenyuan Zhao, Robert A. Ahokas, Tieqiang Zhao, Yao Sun |
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| Rok vydání: | 2011 |
| Předmět: |
Male
medicine.medical_specialty Physiology Adrenergic beta-Antagonists Carbazoles In Vitro Techniques Mitochondrion medicine.disease_cause Antioxidants Mitochondria Heart Capillary Permeability Propanolamines Rats Sprague-Dawley Superoxide dismutase Necrosis chemistry.chemical_compound Integrative Cardiovascular Physiology and Pathophysiology Sarcolemma Stress Physiological Physiology (medical) Internal medicine medicine Animals Homeostasis Myocyte Myocytes Cardiac Endothelium biology Superoxide Dismutase Myocardium MPTP Isoproterenol Skeletal muscle Adrenergic beta-Agonists Rats Oxidative Stress Zinc Endocrinology medicine.anatomical_structure Mitochondrial permeability transition pore chemistry biology.protein Calcium Carvedilol Metallothionein Quercetin Cardiology and Cardiovascular Medicine Oxidative stress |
| Zdroj: | American Journal of Physiology-Heart and Circulatory Physiology. 300:H636-H644 |
| ISSN: | 1522-1539 0363-6135 |
| Popis: | Acute hyperadrenergic stressor states are accompanied by cation dyshomeostasis, together with the release of cardiac troponins predictive of necrosis. The signal-transducer-effector pathway accounting for this pathophysiological scenario remains unclear. We hypothesized that a dyshomeostasis of extra- and intracellular Ca2+ and Zn2+ occurs in rats in response to isoproterenol (Isop) including excessive intracellular Ca2+ accumulation (EICA) and mitochondrial [Ca2+]m-induced oxidative stress. Contemporaneously, the selective translocation of Ca2+ and Zn2+ to tissues contributes to their fallen plasma levels. Rats received a single subcutaneous injection of Isop (1 mg/kg body wt). Other groups of rats received pretreatment for 10 days with either carvedilol (C), a β-adrenergic receptor antagonist with mitochondrial Ca2+ uniporter-inhibiting properties, or quercetin (Q), a flavonoid with mitochondrial-targeted antioxidant properties, before Isop. We monitored temporal responses in the following: [Ca2+] and [Zn2+] in plasma, left ventricular (LV) apex, equator and base, skeletal muscle, liver, spleen, and peripheral blood mononuclear cells (PBMC), indices of oxidative stress and antioxidant defenses, mitochondrial permeability transition pore (mPTP) opening, and myocardial fibrosis. We found ionized hypocalcemia and hypozincemia attributable to their tissue translocation and also a heterogeneous distribution of these cations among tissues with a preferential Ca2+ accumulation in the LV apex, muscle, and PBMC, whereas Zn2+ declined except in liver, where it increased corresponding with upregulation of metallothionein, a Zn2+-binding protein. EICA was associated with a simultaneous increase in tissue 8-isoprostane and increased [Ca2+]m accompanied by a rise in H2O2 generation, mPTP opening, and scarring, each of which were prevented by either C or Q. Thus excessive [Ca2+]m, coupled with the induction of oxidative stress and increased mPTP opening, suggests that this signal-transducer-effector pathway is responsible for Isop-induced cardiomyocyte necrosis at the LV apex. |
| Databáze: | OpenAIRE |
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