Hind-limb protein metabolism in growing sheep; effects of acute and chronic infusion of clenbuterol by close arterial and systemic routes.
1. Close arterial infusion of clenbuterol (0.7 microgram/hr) for a 3 hr period led to decreased protein synthesis and degradation (both P < 0.05) across the hind-limb of sheep. 2. Systemic infusion of the drug (14 micrograms/hr) for a similar period increased blood flow (P < 0.001) through the hind-limb and decreased protein degradation (P < 0.05). 3. Following chronic (7 day) close-arterial infusion of clenbuterol (1.9 micrograms/hr) hind-limb protein synthesis and degradation again declined (P < 0.05) but this was apparently not recovered during 7 days of drug withdrawal. 4. In consequence, during subsequent systemic infusion of the drug (62 micrograms/hr) the lower rates of protein metabolism were not altered significantly, despite improved whole nitrogen retention (+30%, P < 0.01). 5. The results are discussed with reference to the differential actions of beta-agonists on the various tissues of the hind-limb.
Aurousseau
B
B
Rowett Research Institute, Bucksburn, Aberdeen, U.K.
Connell
A
A
Revell
D K
DK
Rocha
H J
HJ
Lobley
G E
GE
D000818:Animals; D001775:Blood Circulation / Q000187:drug effects; D002976:Clenbuterol / Q000008:administration & dosage / Q000494:pharmacology*; D006128:Growth / Q000502:physiology*; D006614:Hindlimb / Q000098:blood supply / Q000378:metabolism*; D007261:Infusions, Intra-Arterial; D007930:Leucine / Q000187:drug effects / Q000378:metabolism; D011506:Proteins / Q000187:drug effects / Q000378:metabolism*; D012756:Sheep
D011506:Proteins; D007930:Leucine; D002976:Clenbuterol