title: Effects of chronic beta-adrenergic blockade on hemodynamic and metabolic responses to endurance training.
abstract: To study the influence of chronic propranolol therapy on hemodynamic and metabolic adaptations associated with endurance training, five dogs given 250 mg X d-1 propranolol therapy (P) and five control dogs (NP) were endurance trained for 7 wk using a continuously increasing treadmill workload. The P group was also evaluated pre- and post-training off the drug (P-OD) to separate drug and training effects. Training lowered mean heart rate score (HR) to a standardized multistage dog treadmill test in the NP and P-OD (P less than 0.05) and had no effect on the HR of the P group while on propranolol. At a fixed submaximal workload there were also slight reductions in cardiac output in the P group which were more pronounced (P less than 0.10) following training, and a corresponding increase in a-vDO2. Pre- and post-training metabolic studies were performed at rest, during a fixed submaximal workload, and following 30 min of recovery. During exercise, blood glucose levels were significantly lower in the P group both before and after training. While NP showed no significant change in high-density lipoprotein bound cholesterol after training, the P-OD group demonstrated a significant fall in high-density lipoprotein bound cholesterol after training (P less than 0.05). These data indicate that endurance exercise training done in the presence of chronic beta-adrenergic blockade produces training-induced hemodynamic adaptations to exercise, but beta-blockade inhibits the changes in serum lipids and lipoprotein fractions normally seen in response to an exercise conditioning program.
authors.forename: M R
authors.initials: MR
authors.lastname: Lawlor
authors.forename: D P
authors.initials: DP
authors.lastname: Thomas
authors.forename: J J
authors.initials: JJ
authors.lastname: Michele
authors.forename: R A
authors.initials: RA
authors.lastname: Carey
authors.forename: A M
authors.initials: AM
authors.lastname: Paolone
authors.forename: A A
authors.initials: AA
authors.lastname: Bove
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D004285:Dogs; D006439:Hemodynamics / Q000187:drug effects; D007773:Lactates / Q000097:blood; D019344:Lactic Acid; D008055:Lipids / Q000097:blood; D008297:Male; D010807:Physical Endurance; D005082:Physical Exertion; D011433:Propranolol / Q000494:pharmacology*
chemical_list: D000319:Adrenergic beta-Antagonists; D001786:Blood Glucose; D007773:Lactates; D008055:Lipids; D019344:Lactic Acid; D011433:Propranolol