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Indenolol, a β‐blocker with partial agonism at vascular β‐adrenoceptors
Author(s) -
Taddei Stefano,
Pedrinelli Roberto,
Salvetti Antonio
Publication year - 1989
Publication title -
clinical pharmacology and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.941
H-Index - 188
eISSN - 1532-6535
pISSN - 0009-9236
DOI - 10.1038/clpt.1989.186
Subject(s) - propranolol , forearm , plethysmograph , antagonist , stimulation , medicine , blood pressure , heart rate , blockade , hemodynamics , saline , blood flow , anesthesia , chemistry , pharmacology , receptor , anatomy
Intrinsic sympathomimetic activity may attenuate some effects caused by treatment with β‐adrenoceptor blockers. Indenolol is a nonselective β‐adrenoceptor antagonist whose sympathomimetic properties have been shown in vitro but not in human beings. We infused indenolol cumulatively (5, 15, and 50 µg/100 ml tissue per minute for 15 minutes each, preceded by an infusion of saline solution) into the brachial arteries of nine hypertensive patients. Forearm blood flow (venous plethysmography), mean arterial pressure, and heart rate were monitored. During infusion at 5 µg/100 ml tissue per minute, forearm blood flow did not change, but it did increase dose‐dependently at the greater infusion rates. This action was determined to be mediated by β‐adrenoceptor stimulation because propranolol (10 µg/100 ml tissue per minute for 15 minutes), given before treatment and then concomitantly with indenolol, abolished it ( n = 5). Indenolol vasodilated forearm arterioles and this effect was antagonized by β‐blockade, thus demonstrating vascular intrinsic sympathomimetic activity. This property may contribute to its therapeutic action in human beings. Clinical Pharmacology and Therapeutics (1989) 46, 560–565; doi: 10.1038/clpt.1989.186