Intraventricular changes in the beta-adrenoceptor-adenylate cyclase system of the rat heart with the progress of monocrotaline-induced right ventricular hypertrophy.
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.
Yoshie
H
H
First Department of Internal Medicine, Asahikawa Medical College, Japan.
Tobise
K
K
Onodera
S
S
D015720:5'-Nucleotidase / Q000378:metabolism; D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D002462:Cell Membrane / Q000201:enzymology / Q000378:metabolism; D006346:Heart Septum / Q000201:enzymology / Q000378:metabolism; D006352:Heart Ventricles / Q000201:enzymology / Q000378:metabolism; D017380:Hypertrophy, Right Ventricular / Q000139:chemically induced / Q000201:enzymology / Q000378:metabolism*; D008297:Male; D016686:Monocrotaline / Q000009:adverse effects*; D009206:Myocardium / Q000201:enzymology / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011943:Receptors, Adrenergic, beta / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism
D011943:Receptors, Adrenergic, beta; D016686:Monocrotaline; D015720:5'-Nucleotidase; D000262:Adenylyl Cyclases; D000254:Sodium-Potassium-Exchanging ATPase