Cardiovascular responses to graded treadmill exercise during the development of doxorubicin induced heart failure in rabbits

Cardiovascular Research
D LangtonJ Ludbrook

Abstract

The aim was to examine the haemodynamic and humoral responses to graded treadmill exercise, serially during the development of congestive heart failure. Doxorubicin (1 mg.kg-1) was given to rabbits twice weekly intravenously over 8 weeks to induce a low output congestive cardiomyopathy. Treadmill exercise at 8 and 16 m.min-1 was performed at weeks 0, 2, 4, 6, 7, and 8. During each exercise study, continuous recordings were made of cardiac output, mean arterial pressure, and heart rate, and central venous blood was sampled at rest and during the last 10 s of exercise for plasma noradrenaline and plasma renin activity. Six cross-bred English rabbits, mean weight 2.6 kg, received doxorubicin treatment; three control rabbits received vehicle injection. Over the first 2 weeks, resting haemodynamic variables and responses to exercise were normal in all rabbits. Thereafter, doxorubicin treated rabbits had progressive falls in resting cardiac index and mean arterial pressure, and rises in resting heart rate and systemic vascular resistance. The normal increases in cardiac index and mean arterial pressure with exercise were progressively attenuated, despite an increase in resting and exercising heart rate. The resting levels of plasma n...Continue Reading

Citations

Mar 2, 1994·Biochemical Pharmacology·L L Ji, E W Mitchell
Apr 1, 1993·Baillière's Clinical Endocrinology and Metabolism·K Shimizu, B P McGrath
Mar 1, 1990·Clinical and Experimental Pharmacology & Physiology·D LangtonB McGrath
Jun 1, 1995·Clinical and Experimental Pharmacology & Physiology·V MoguilevskiB P McGrath

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