Increased muscle strength in paralyzed patients after spinal cord injury: effect of beta-2 adrenergic agonist.
The administration of beta-2 adrenergic agonists in experimental animals result in an increased strength of skeletal muscle. In this study, we evaluated whether a beta-2 adrenergic agonist, metaproterenol, had an effect on muscle size and strength in a group of patients with muscular atrophy following spinal cord injury. Ten male subjects were randomly divided into 2 groups and agreed to participate in a prospective, double-blind, placebo-controlled, and crossover study. Metaproterenol (80 mg/day), or placebo, was administered orally for a period of 4 weeks. Muscle strength was measured by a force transducer interfaced with a microcomputer. Muscle size was calculated and expressed as a cross-sectional area of upper arm and forearm using a formula. Metaproterenol induced a significant increase of muscle strength in both groups of subjects, compared with placebo (p < .001). Similarly, there was an increase in a muscle size in the forearm following the administration of metaproterenol. Our data indicate that beta-2 adrenergic agonists may improve both muscle strength and size in patients with muscular atrophy following spinal cord paralysis.
Signorile
J F
JF
Department of Exercise and Sport Sciences, School of Medicine, University of Miami, FL 33101.
Banovac
K
K
Gomez
M
M
Flipse
D
D
Caruso
J F
JF
Lowensteyn
I
I
D000328:Adult; D001696:Biomechanical Phenomena; D004311:Double-Blind Method; D006801:Humans; D008297:Male; D009921:Metaproterenol / Q000627:therapeutic use*; D009132:Muscles / Q000473:pathology / Q000503:physiopathology; D009133:Muscular Atrophy / Q000188:drug therapy* / Q000209:etiology / Q000473:pathology; D010243:Paralysis / Q000188:drug therapy* / Q000209:etiology; D011446:Prospective Studies; D013119:Spinal Cord Injuries / Q000150:complications*
D009921:Metaproterenol