Effects of acute cardioselective and non-selective beta-adrenergic blockade on plasma ammonia levels in exercising dogs.
The aim of this study was to assess plasma ammonia levels during acute treadmill exercise in dogs after intravenous administration of a single dose of different cardioselective (atenolol) and non-selective (sotalol and propranolol) beta-adrenergic blocking drugs. The experiments were performed on 6 male mongrel dogs (20-25 kg) trained to run on a motor driven treadmill. After administration of saline or atenolol, there was no significant increase in plasma ammonia during exercise; propranolol and sotalol however, both non-selective beta-blockers, produced a significant increase in plasma ammonia. Plasma levels of alanine and glutamine were not altered during exercise compared with resting values, and were not modified by the administration of beta-blockers. It is not clear whether the different effects on exercise induced hyperammonemia are due to different effects on muscle ammonia formation or on the ammonia clearance by the liver.
Matthys
D
D
Division of Pediatrics, University Hospital Gent; Belgium.
Calders
P
P
Kint
J
J
Pannier
J L
JL
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000641:Ammonia / Q000097:blood*; D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology*; D001262:Atenolol / Q000494:pharmacology; D004285:Dogs; D004353:Drug Evaluation, Preclinical; D005069:Evaluation Studies as Topic; D006339:Heart Rate / Q000187:drug effects; D007262:Infusions, Intravenous; D008297:Male; D010805:Physical Conditioning, Animal / Q000502:physiology*; D011433:Propranolol / Q000494:pharmacology; D013015:Sotalol / Q000494:pharmacology
D000319:Adrenergic beta-Antagonists; D000889:Anti-Arrhythmia Agents; D001262:Atenolol; D000641:Ammonia; D011433:Propranolol; D013015:Sotalol