Regional differences in rest decay and recoveries of contraction and the calcium transient in rabbit ventricular muscle

1995 ◽  
Vol 430 (2) ◽  
pp. 195-204 ◽  
Author(s):  
J. P. Chamunorwa ◽  
S. C. O'Neill
Keyword(s):  
Regional Differences ◽  
Calcium Transient ◽  
Ventricular Muscle ◽  
Rabbit Ventricular Muscle

State of creatine in mammalian heart muscle

1960 ◽  
Vol 198 (4) ◽  
pp. 855-858 ◽  
Author(s):  
Y. C. P. Lee ◽  
R. A. Dewall ◽  
M. B. Visscher
Keyword(s):  
Heart Muscle ◽  
Inorganic Phosphate ◽  
Artificial Respiration ◽  
Rabbit Heart ◽  
Potassium Citrate ◽  
Ventricular Muscle ◽  
Phosphate Content ◽  
Total Creatine ◽  
Mammalian Heart Muscle ◽  
Rabbit Ventricular Muscle

Studies were performed on the total creatine, phosphocreatine and inorganic phosphate content of rabbit ventricular muscle from animals sacrificed under various conditions. The highest values of phosphocreatine, averaging 59.6% of the total creatine, were found in hearts arrested by intra-aortic infusion of alkaline potassium citrate solutions. Approximately the same values were found after sodium citrate arrest. Potassium chloride arrest resulted in a finding of only half as much phosphocreatine. Hearts removed without previous arrest likewise showed phosphocreatine values far below those found after citrate arrest. Acetylcholine arrest did not yield high values. Animals sacrificed by stunning, followed immediately by artificial respiration with 100% O2 showed the lowest quantities of cardiac phosphocreatine. Adrenaline administration to the animal prior to potassium citrate arrest was followed by very low phosphocreatine levels. The inorganic phosphate content of rabbit heart muscle is in general inversely proportional to the phosphocreatine, and directly proportional to the free creatine levels. Assuming a linear correlation one finds that there appears to be 75 mg% of free creatine in the rabbit ventricular muscle at the time of instantaneous arrest under optimal conditions.

Inactivation of the β-adrenergic receptor in cardiac muscle by dithiols

1985 ◽  
Vol 63 (8) ◽  
pp. 932-936 ◽  
Author(s):  
Trevor I. Prior ◽  
Vandana Patel ◽  
G. I. Drummond
Keyword(s):  
Adrenergic Receptor ◽  
Reduced Glutathione ◽  
Binding Capacity ◽  
Specific Binding ◽  
Binding Activity ◽  
Ventricular Muscle ◽  
Adrenergic Antagonist ◽  
Equilibrium Dissociation ◽  
Rabbit Ventricular Muscle ◽  
Membrane Binding Sites

The effect of sulfhydryl reagents on binding of the β-adrenergic antagonist (−)-[3H]dihydroalprenolol hydrochloride ((−)-[3H]DHA) to a microsomal fraction of rabbit ventricular muscle was studied. Incubation with the disulfide reducing agents dithiothreitol (DTT), 2-mercaptocthanol, and reduced glutathione resulted in loss of (−)-[3H]DHA binding. At 500 μM DTT, less than 50% of specific binding activity remained; at 100 mM, binding was completely eliminated. 2-Mercaptoethanol and reduced glutathione were less effective than DTT at inhibiting binding activity. The total binding capacity (Bmax) decreased from 155.4 fmol mg−1 of protein, in the absence of DTT, to 92.4 and 77.5 fmol mg−1 at 0.25 and 0.7 mM DTT, respectively. The equilibrium dissociation constant (KD) increased from 7.6 nM, in the absence of DTT, to 10.3 nM at 0.25 mM DTT and to 20.8 nM at 0.7 mM DTT. Thus, DTT-induced decline in (−)-[3H]DHA binding results from a decrease in both the number and affinity of membrane binding sites for the tracer. Receptors could be protected from DTT inactivation by preincubation with β-adrenergic ligands. Oxidants could not reverse inactivation, with the exception of o-iodosobenzoate which was only partially effective. Thus, the β-adrenergic receptor of rabbit ventricular muscle contains essential disulfide moietie(s) which can be inactivated by reducing thiols.

scholarly journals Electrophysiological effects of disopyramide on hypoxic rabbit ventricular muscle.

1982 ◽  
Vol 46 (7) ◽  
pp. 663-668
Author(s):  
HIROKO MATSUDA ◽  
TOMOTSUGU KONISHI ◽  
TOSHITAKE TAMAMURA ◽  
MAKOTO KADOYA ◽  
CHUICHI KAWAI
Keyword(s):  
Ventricular Muscle ◽  
Rabbit Ventricular Muscle ◽  
Electrophysiological Effects
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