Attenuation of hypertension, cardiomyocyte hypertrophy, and myocardial fibrosis by beta-adrenoceptor blockers in rats under long-term blockade of nitric oxide synthesis.

Abstract

The effects of propranolol and atenolol were investigated on arterial hypertension, cardiomyocyte hypertrophy, and ventricular ischaemic lesions induced by an 8-week treatment with the nitric oxide synthase inhibitor N(omega)-nitro-L-arginine methyl ester (L-NAME; 20 mg/rat per day) in Wistar rats. Propranolol and atenolol (30 mg/rat per day each) were given in the drinking water concomitantly to L-NAME. Treatment with L-NAME induced marked arterial hypertension and cardiomyocyte hypertrophy, both of which were significantly reduced by propranolol and atenolol. A marked repairing fibrosis was also observed in L-NAME-treated rats and this was significantly attenuated in animals receiving the beta-blockers. In L-NAME group, 33% mortality was observed, whereas all the animals from the other groups survived. Our study demonstrates that propranolol and atenolol reduce arterial hypertension, cardiomyocyte hypertrophy and myocardial fibrosis induced by L-NAME, suggesting that beta-blockers are of beneficial value in treatment of vascular and cardiac alterations caused by chronic nitric oxide deficiency.

• Authors: Sandra R M C Pacca, Ana Paula de Azevedo, Claudia F De Oliveira, Iara M S De Luca, Gilberto De Nucci, Edson Antunes
• Journal: Journal of cardiovascular pharmacology (J Cardiovasc Pharmacol) Vol. 39 Issue 2 Pg. 201-7 (Feb 2002) ISSN: 0160-2446 [Print] United States
• PMID: 11791005 (Publication Type: Journal Article)

Chemical References

• Adrenergic beta-1 Receptor Antagonists
• Adrenergic beta-Antagonists
• Enzyme Inhibitors
• Nitric Oxide
• Atenolol
• Propranolol
• Nitric Oxide Synthase
• NG-Nitroarginine Methyl Ester

Topics

• Adrenergic beta-1 Receptor Antagonists
• Adrenergic beta-Antagonists (pharmacology, therapeutic use)
• Animals
• Atenolol (pharmacology, therapeutic use)
• Blood Pressure (drug effects)
• Body Weight (drug effects)
• Enzyme Inhibitors
• Fibrosis
• Heart (anatomy & histology, drug effects)
• Hypertension (chemically induced, drug therapy)
• Hypertrophy, Left Ventricular (chemically induced, drug therapy, pathology)
• Male
• Myocardium (pathology)
• NG-Nitroarginine Methyl Ester
• Nitric Oxide (deficiency)
• Nitric Oxide Synthase (antagonists & inhibitors)
• Organ Size (drug effects)
• Propranolol (pharmacology, therapeutic use)
• Rats
• Rats, Wistar
• Time Factors