1. Intraventricular changes in the .BETA.-adrenoceptor-adenylate cyclase system of the rat heart with the progress of monocrotaline-induced right ventricular hypertrophy
- Author
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Sokichi Onodera, Katsuyuki Tobise, and Hiromitsu Yoshie
- Subjects
Male ,medicine.medical_specialty ,Physiology ,Heart Ventricles ,Adenylate kinase ,Biology ,Cyclase ,Muscle hypertrophy ,Rats, Sprague-Dawley ,Right ventricular hypertrophy ,Internal medicine ,Receptors, Adrenergic, beta ,Heart Septum ,medicine ,Animals ,heterocyclic compounds ,Interventricular septum ,5'-Nucleotidase ,Monocrotaline ,Hypertrophy, Right Ventricular ,Myocardium ,Cell Membrane ,medicine.disease ,Rats ,medicine.anatomical_structure ,Endocrinology ,Ventricle ,Heart failure ,cardiovascular system ,Cardiology ,Sodium-Potassium-Exchanging ATPase ,Cardiology and Cardiovascular Medicine ,Cyclase activity ,Adenylyl Cyclases - Abstract
We investigated the changes in the membranous beta-adrenoceptor-adenylate cyclase system in the right ventricle, left ventricle and interventricular septum during the progress of monocrotaline-induced right ventricular hypertrophy and failure. The beta-adrenoceptor density was decreased in hypertrophied right ventricle 2 to 4 weeks after treatment. When the rats showed symptoms of right ventricular failure 4 weeks after treatment, the beta-adrenoceptor density was decreased in the interventricular septum. Both basal and forskolin-stimulated adenylate cyclase activities were decreased in the right ventricle at 3 and 4 weeks, and in the interventricular septum at 4 weeks, after treatment, which indicates that the catalytic activity of adenylate cyclase is reduced. Changes in isoproterenol plus Gpp (NH) p- or sodium fluoride-stimulated adenylate cyclase activity were generally similar to those in basal activity. These data indicate that a chamber-specific decrease in beta-adrenoceptor density begins in the early stages of right ventricular hypertrophy, and that beta-adrenoceptor density and adenylate cyclase activity in the interventricular septum are decreased in the advanced stages of heart failure in monocrotaline-treated rats.
- Published
- 1994
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