01 August 2010
Hypertrophied myocardium is more dependent on extracellular calcium than the normal cardiac muscle
Reginaldo de BarrosABCF, Leonardo A.M. ZornoffCDEF, Henrique B. RibeiroBF, Marina P. OkoshiBCDEF, Carlos R. PadovaniC, Flavio F. AragonC, Antonio C. CicognaABCDEFGMed Sci Monit 2010; 16(8): BR :: ID: 881100
Abstract
Background: The aim of this study was to analyze stable hypertrophied myocardial function and its response to inotropic maneuvers in rats submitted to renovascular hypertension for a 10-week period (RHT group, n=10).
Material/Methods: Myocardial performance was studied in isolated left ventricle papillary muscles in isometric contraction under the following conditions: at postrest contraction of 30 seconds (PRC), at extracellular calcium (ECa2+) chloride concentration of 1.25 and 5.20mM, and after beta-adrenergic stimulation with 10–6 M isoproterenol (ISOP).
Results: The results were compared with normotensive Wistar controls rats (C group, n=10). In basal condition, resting tension, and contraction time (TPT) were greater, while relaxation time (RT50) tended to be longer in RHT than C group. PRC and ISOP promoted a similar change in muscle function response intensity (delta) in both groups. ECa2+ shift did not change TPT in the C group and decreased TPT in the RHT animals; delta was different between these groups. RT50 increased in C and decreased in RHT, both without statistical significance; however, delta was different.
Conclusions: These results suggest that hypertrophied myocardial dysfunction may be attributed to changes in intracellular calcium cycling.
Keywords: Myocardial Contraction - drug effects, Isoproterenol - pharmacology, Isometric Contraction - drug effects, Hypertrophy, Extracellular Space - metabolism, Calcium - pharmacology, Blood Pressure - drug effects, Myocardium - pathology, Rats, Wistar, Rest - physiology, Systole - drug effects
Editorial
01 April 2024 : Editorial
Editorial: Forty Years of Waiting for Prevention and Cure of HIV Infection – Ongoing Challenges and Hopes for Vaccine Development and Overcoming Antiretroviral Drug ResistanceDOI: 10.12659/MSM.944600
Med Sci Monit 2024; 30:e944600
In Press
05 Mar 2024 : Clinical Research
Effects of Thermal Insulation on Recovery and Comfort of Patients Undergoing Holmium Laser LithotripsyMed Sci Monit In Press; DOI: 10.12659/MSM.942836
05 Mar 2024 : Clinical Research
Role of Critical Shoulder Angle in Degenerative Type Rotator Cuff Tears: A Turkish Cohort StudyMed Sci Monit In Press; DOI: 10.12659/MSM.943703
06 Mar 2024 : Clinical Research
Comparison of Outcomes between Single-Level and Double-Level Corpectomy in Thoracolumbar Reconstruction: A ...Med Sci Monit In Press; DOI: 10.12659/MSM.943797
21 Mar 2024 : Meta-Analysis
Economic Evaluation of COVID-19 Screening Tests and Surveillance Strategies in Low-Income, Middle-Income, a...Med Sci Monit In Press; DOI: 10.12659/MSM.943863
Most Viewed Current Articles
17 Jan 2024 : Review article
Vaccination Guidelines for Pregnant Women: Addressing COVID-19 and the Omicron VariantDOI :10.12659/MSM.942799
Med Sci Monit 2024; 30:e942799
14 Dec 2022 : Clinical Research
Prevalence and Variability of Allergen-Specific Immunoglobulin E in Patients with Elevated Tryptase LevelsDOI :10.12659/MSM.937990
Med Sci Monit 2022; 28:e937990
16 May 2023 : Clinical Research
Electrophysiological Testing for an Auditory Processing Disorder and Reading Performance in 54 School Stude...DOI :10.12659/MSM.940387
Med Sci Monit 2023; 29:e940387
01 Jan 2022 : Editorial
Editorial: Current Status of Oral Antiviral Drug Treatments for SARS-CoV-2 Infection in Non-Hospitalized Pa...DOI :10.12659/MSM.935952
Med Sci Monit 2022; 28:e935952