Propranolol Diminishes Cardiac Hypertrophy But Does Not Abolish Acceleration of the Ischemic Contracture in Hyperthyroid Hearts
| Autor: | Panagiotis Asimacopoulos, Vassiliki Malliopoulou, Dennis Varonos, Iordanis Mourouzis, Stylianos Tzeis, Dennis V. Cokkinos, Hariclia Carageorgiou, Constantinos Pantos, Demosthenes D. Cokkinos |
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| Rok vydání: | 2000 |
| Předmět: |
Male
medicine.medical_specialty medicine.medical_treatment Adrenergic beta-Antagonists Myocardial Ischemia Ischemia Adrenergic Myocardial Reperfusion Propranolol Antiarrhythmic agent Left ventricular hypertrophy Hyperthyroidism Muscle hypertrophy Internal medicine medicine Animals cardiovascular diseases Rats Wistar Pharmacology business.industry Ischemic Contracture medicine.disease Myocardial Contraction humanities Rats Endocrinology Hypertrophy Left Ventricular Contracture medicine.symptom Cardiology and Cardiovascular Medicine business Glycogen medicine.drug |
| Zdroj: | Journal of Cardiovascular Pharmacology. 36:384-389 |
| ISSN: | 0160-2446 |
| DOI: | 10.1097/00005344-200009000-00015 |
| Popis: | This study was undertaken to define the contributions of left ventricular hypertrophy (LVH) and increased adrenergic activity to the acceleration of ischemic contracture (IC) that occurs in chronic hyperthyroid rat heart. Acute and chronic hyperthyroidism (THYR) were induced by thyroxine administration for 2 and 14 days, respectively, and normal animals (NORM) served as controls. Isolated hearts were perfused in a Langendorff mode. NORM alpha acute, n = 6; THYR alpha acute, n = 8; and THYR alpha, n = 13; and NORM alpha, n = 13 were subjected to 20-min zero-flow global ischemia (I) and 45-min reperfusion (R). Additional THYR and NORM hearts treated with propranolol (prop) were subjected to 30-min I; THYR beta prop, n = 6 and NORM beta prop, n = 8, and THYR beta, n = 6, NORM beta, n = 8 served as controls. Acceleration of IC was measured by the time to peak contracture (Tmax). Left ventricular hypertrophy (LVH) was assessed by the ratio of left ventricular weight in milligrams (LVW) to animal body weight (BW) in grams. Cardiac hypertrophy developed in chronic but not acute hyperthyroidism. Propranolol reduced the extent of LVH. Contracture occurred earlier in chronic than in acute hyperthyroid and normal hearts. Propranolol did not alter contracture. In conclusion, IC is accelerated by thyroxine administration, and this is probably not due to LVH or increased beta-adrenergic activity. Propranolol diminishes LVH in hyperthyroidism. |
| Databáze: | OpenAIRE |
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