[Effects of calcium antagonists on withdrawal of beta-receptor blockers in rats during left ventricular hypertrophy].

Abstract

The hemodynamic changes of metoprolol (Met, 50 mg.kg-1.d-1, po, 3 wk) withdrawal for 1 day and the effects of nifedipine (Nif) and m-nifedipine (m-Nif) on these changes were observed in pressure overload hypertrophy in rats by abdominal aortic constriction for 4 wk. Both Nif and m-Nif (10 mg.kg-1.d-1, respectively, po, 3 wk) significantly attenuated the increase of MAP (from 14.3 +/- 2.3 to 12.9 +/- 2.3 and 11.3 +/- 2.4 kPa, respectively, n = 6-7, P < 0.05) and decrease the abnormal development of systolic function of left ventricle after Met withdrawal. Radioreceptor assay indicates that Nif and m-Nif can prevent the up-regulation of myocardium beta-receptors in left ventricular hypertrophy and large dose of Met exposure for a long time. These results suggest that calcium antagonists administered with beta-blockers can prevent beta-receptor blocker withdrawal syndrome.

• Authors: Q P Li, M R Rao
• Journal: Yao xue xue bao = Acta pharmaceutica Sinica (Yao Xue Xue Bao) Vol. 30 Issue 1 Pg. 21-6 ( 1995) ISSN: 0513-4870 [Print] China
• PMID: 7660786 (Publication Type: English Abstract, Journal Article)

Chemical References

• Receptors, Adrenergic, beta
• Metoprolol
• Nifedipine

Topics

• Animals
• Hemodynamics (drug effects)
• Hypertrophy, Left Ventricular (drug therapy)
• Isomerism
• Male
• Metoprolol (adverse effects, therapeutic use)
• Myocardium (metabolism)
• Nifedipine (pharmacology, therapeutic use)
• Rats
• Rats, Sprague-Dawley
• Receptors, Adrenergic, beta (metabolism)
• Substance Withdrawal Syndrome (metabolism, physiopathology, prevention & control)