Article date: March 1992
By: OE Brodde, HJ Hundhausen, HR Zerkowski, MC Michel, in Volume 33, Issue 3, pages 269-274
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)
DOI: 10.1111/j.1365-2125.1992.tb04034.x
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