ABSTRACT
The influence of small doses of exogenic nitrite on reversible and irreversible oxidative modifications of water-soluble proteins of rat cardiac and skeletal muscle was studied with the aid of redox 2D-electrophoresis and colorimetric determination of protein carbonyl group, correspondingly. To explain the absence of significant changes under hypoxia induced by nitrite the known hypothesis about nitrite inhibition of some sites of mitochondrial electron transporting chain decreasing free radical quantity was discussed.
Subject(s)
Mitochondria, Heart/metabolism , Muscle Proteins/metabolism , Muscle, Skeletal/metabolism , Myocardium/metabolism , Nitrites/pharmacology , Protein Processing, Post-Translational/drug effects , Animals , Oxidation-Reduction/drug effects , Rats , Rats, Wistar , Solubility/drug effectsSubject(s)
Calcium/metabolism , Cardiac Output/drug effects , Heart/physiopathology , Myocardium/metabolism , Shock, Cardiogenic/physiopathology , Adenylyl Cyclase Inhibitors , Adenylyl Cyclases/metabolism , Animals , Aprotinin/pharmacology , Aprotinin/therapeutic use , Disease Models, Animal , Dogs , Enzyme Inhibitors/pharmacology , Enzyme Inhibitors/therapeutic use , Heart/drug effects , Hemodynamics/drug effects , Molybdenum/pharmacology , Molybdenum/therapeutic use , Myocardium/enzymology , Protein Kinase Inhibitors , Protein Kinases/metabolism , Sarcoplasmic Reticulum/enzymology , Sarcoplasmic Reticulum/metabolism , Shock, Cardiogenic/drug therapy , Shock, Cardiogenic/enzymology , Shock, Cardiogenic/metabolism , Ventricular Function, Left/drug effectsABSTRACT
It was shown on dog experiments that disorders in the phosphorylation-proteolysis-calcium transport system in the sarcoplasmatic reticulum of pathologically changed myocardium are an important component of cardiac activity depression in massive blood loss. Low cardiac output can be corrected by ammonium molibdate, phosphoprotein phosphatase inhibitor, and contrycal, proteolysis inhibitor.
Subject(s)
Aprotinin/therapeutic use , Cardiac Output, Low/drug therapy , Coloring Agents/therapeutic use , Hemostatics/therapeutic use , Molybdenum/therapeutic use , Myocardium/cytology , Phosphoprotein Phosphatases/antagonists & inhibitors , Serine Proteinase Inhibitors/therapeutic use , Trypsin Inhibitors/therapeutic use , Animals , Cardiac Output, Low/etiology , Cardiac Output, Low/metabolism , Dogs , Hemorrhage/complications , Models, Theoretical , Sarcoplasmic Reticulum/metabolismABSTRACT
The possibility of involvement of thyroid hormones and melatonin in cell protection from damage by active oxygen forms (hydroxyperoxide, superoxide radical, and hypochlorite) was investigated. The intensity of inhibition of luminol-dependent chemiluminescence induced by neutrophils and active oxygen forms in the presence of hormones was evaluated. Antioxidant activities of the enzymes were compared with that of glutathione. Probable mechanisms of antioxidant effect of the studied hormones are discussed.
Subject(s)
Antioxidants , Melatonin/physiology , Thyroid Hormones/physiology , Humans , Luminescent Measurements , Neutrophil Activation , Neutrophils/physiology , Oxidative Stress , Reactive Oxygen SpeciesABSTRACT
After hypochlorite (OCl-) treatment of the aortic smooth muscle sarcoplasmic reticulum (SR), the membrane microviscosity increases considerably in "bound" lipid regions in comparison with protein-free regions. OCl- induces the inhibition of active and the enhancement of passive calcium transport in SR. Treatment of SR vesicles with Ag+ and then with OCl- (but not in the reverse order) leads to the enhancement of the activating effect of OCl- on passive calcium release from the vesicles. It is concluded that the enhancement effect is due to the OCl(-)-induced increase in the passive permeability of the SR membrane for Ca2+ as a result of pore formation in the lipid bilayer.
Subject(s)
Calcium/metabolism , Hypochlorous Acid/pharmacology , Sarcoplasmic Reticulum/metabolism , Silver/pharmacology , Animals , Biological Transport , Intracellular Membranes/metabolism , Microsomes/drug effects , Microsomes/metabolism , Muscle, Smooth/drug effects , Muscle, Smooth/metabolism , Permeability , RabbitsSubject(s)
Aorta/metabolism , Calcium/metabolism , Myocardium/metabolism , Sarcoplasmic Reticulum/metabolism , Animals , Biological Transport , Cations, Divalent , Cells, Cultured , Dogs , Hydrolysis , Hypochlorous Acid/chemistry , Microsomes/metabolism , Oxidation-Reduction , Phosphorylation , RabbitsABSTRACT
The oxygen isotope exchange reactions catalyzed by sea urchin Strongylocentrotus intermedius spermatozoa dynein I were studied with a view of comparing molecular mechanisms of ATP hydrolysis by dynein and myosin ATPases. It was demonstrated that the isotope exchange takes place during ATP hydrolysis and during enzyme incubation with ADP and Pi and is absent when the enzyme is incubated with Pi. It was assumed that the molecular mechanisms of ATP hydrolysis by dynein I and myosin are identical.
Subject(s)
Adenosine Triphosphatases/metabolism , Dyneins/metabolism , Spermatozoa/enzymology , Animals , Histocytochemistry , Kinetics , Male , Microscopy, Electron , Oxygen Isotopes , Phosphates , Sea Urchins , Spermatozoa/ultrastructureABSTRACT
18O-exchange reactions of skeletal, cardiac and smooth muscle myosin were studied. All investigated preparations of myosin catalyse two types of 18O-exchange--intermediate and direct exchanges in the presence of Mg2+. The dependence of 18O-exchange extent on divalent cations have appeared to be similar for different muscle types. This supports the hypothesis of similarity of ATP hydrolysis molecular mechanisms by myosin of different origin.
Subject(s)
Muscle, Smooth/metabolism , Muscles/metabolism , Myocardium/metabolism , Myosins/metabolism , Animals , Dogs , Humans , Magnesium/pharmacology , Oxygen Isotopes , RabbitsABSTRACT
18O-exchange reactions of smooth muscle myosin of calf intestine were studied. Smooth muscle myosin, similar to skeletal myosin, catalyses two types of 18O-exchange reactions--intermediate and direct. Only quantitative differences of the exchange intensity are observed. 18O-exchange dependence on bivalent cation and nucleotide nature is found. The comparison of 18O-exchange characteristics for myosins of smooth and skeletal muscles confirms the hypothesis on the similarity of molecular mechanisms of ATP hydrolysis by myosin from different muscle types.
Subject(s)
Muscle, Smooth/metabolism , Myosins/metabolism , Oxygen , Adenosine Triphosphate/metabolism , Animals , Catalysis , Cations, Divalent , Cattle , Hydrolysis , Intestinal Mucosa/metabolism , Muscles/anatomy & histology , Muscles/metabolism , Nucleotides/pharmacologyABSTRACT
Mg2+-Dependent, Ca2+-activated adenosine triphosphatase (E. C. 3.6.1.4) of synaptosomal plasmatic membrane from cow brain catalyses isotopic exchange of oxygen atoms: KH2P18O 4 in equilibrium H2O, the degree of exchange depending on Ca2+ concentration. The 18O-exchange catalysis suggests that the enzyme under consideration acts as a transport ATPase.
