Lack of effect of chronic calcium antagonist treatment on beta 1- and beta 2-adrenoceptors in right atria from patients with or without heart failure.
1. We studied the effects of chronic calcium antagonist (calcium entry blocker, CEB; nifedipine, verapamil, diltiazem) treatment on beta-adrenoceptor density (assessed by (-)-[125I]-iodocyanopindolol [ICYP] binding) and subtype distribution in right atria from 65 patients without apparent heart failure undergoing elective coronary artery bypass grafting (CAD-patients) and from 13 patients with moderate heart failure (NYHA class III to class III-IV) undergoing mitral valve replacement (MVD-patients). 2. In CAD-patients atrial beta-adrenoceptor density was 79.3 +/- 7.9 fmol ICYP bound mg-1 protein (n = 18), the beta 1:beta 2-adrenoceptor ratio 69:31%. Chronic CEB-treatment did not affect either atrial beta-adrenoceptor density or beta 1:beta 2-adrenoceptor ratio. 3. In contrast, in CAD-patients chronically treated with beta 1-adrenoceptor antagonists (atenolol, bisoprolol, metoprolol) and CEB, atrial beta-adrenoceptor density was significantly increased (108.6 +/- 10.5 fmol ICYP bound mg-1 protein, n = 21); this increase was due to a selective increase in beta 1-adrenoceptors. 4. In MVD-patients atrial beta-adrenoceptor density (55.5 +/- 8.7 fmol ICYP bound mg-1 protein, n = 7) was significantly lower (P less than 0.05) than in CAD-patients; beta 1:beta 2-adrenoceptor ratio, however, was not changed (67:33%). Chronic CEB-treatment of MVD-patients did not prevent the decrease in atrial beta-adrenoceptors. 5. We conclude that chronic CEB-treatment does not affect human right atrial beta-adrenoceptor density, either in patients without apparent heart failure or in patients with moderate heart failure.(ABSTRACT TRUNCATED AT 250 WORDS)
Brodde
O E
OE
Department of Internal Medicine, University of Essen, Germany.
Hundhausen
H J
HJ
Zerkowski
H R
HR
Michel
M C
MC
D000328:Adult; D000368:Aged; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D001026:Coronary Artery Bypass; D003327:Coronary Disease / Q000601:surgery*; D004110:Diltiazem / Q000494:pharmacology; D005260:Female; D006325:Heart Atria / Q000187:drug effects*; D006801:Humans; D008214:Lymphocytes / Q000187:drug effects / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009543:Nifedipine / Q000494:pharmacology; D011943:Receptors, Adrenergic, beta / Q000187:drug effects*; D014700:Verapamil / Q000494:pharmacology
D002121:Calcium Channel Blockers; D011943:Receptors, Adrenergic, beta; D014700:Verapamil; D004110:Diltiazem; D009543:Nifedipine