Muscle wasting associated with endotoxemia in the rat: modification by the beta 2-adrenoceptor agonist clenbuterol.
A single injection of endotoxin (1 mg/kg, sc) in rats caused significant fever, body weight loss and reduction in gastrocnemius muscle mass, none of which was mimicked by pair-feeding. Infusion of endotoxin via osmotic minipump over five days caused transient fever and suppression of growth. Recovery of body weight was significantly enhanced by the administration of the beta 2-adrenoceptor agonist clenbuterol (added to the diet at 4 mg/kg). In a separate experiment, injections of endotoxin (day 0 and day 2) caused significant reductions in body weight gain (42%), mass (9%) and protein content (13%) of gastrocnemius muscle over 3 days. Addition of clenbuterol to the diet reversed all of these effects but did not alter food intake or the febrile response to endotoxin. Clenbuterol caused large (20%) increases in the ratio of RNA to protein in muscle indicating that it may have stimulated protein synthesis. beta 2-adrenoceptor agonists may therefore be of value in preventing or inhibiting muscle atrophy associated with infection or injury.
Choo
J J
JJ
Department of Physiological Sciences, University of Manchester, UK.
Horan
M A
MA
Little
R A
RA
Rothwell
N J
NJ
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002976:Clenbuterol / Q000627:therapeutic use*; D004731:Endotoxins / Q000633:toxicity; D004983:Ethanolamines / Q000627:therapeutic use*; D008297:Male; D009133:Muscular Atrophy / Q000188:drug therapy* / Q000209:etiology / Q000473:pathology; D051381:Rats; D011919:Rats, Inbred Strains; D014115:Toxemia / Q000150:complications*
D004731:Endotoxins; D004983:Ethanolamines; D002976:Clenbuterol