title: Effect of hindlimb suspension and clenbuterol treatment on polyamine levels in skeletal muscle.
abstract: Polyamines are unbiquitous, naturally occurring small aliphatic, polycationic, endogenous compounds. They are involved in many cellular processes and may serve as secondary or tertiary messengers to hormonal regulation. The relationship of polyamines and skeletal muscle mass of adductor longus, extensor digitorum longus, and gastrocnemius under unloading (hindlimb suspension) conditions was investigated. Unloading significantly affected skeletal muscle polyamine levels in a fiber-type-specific fashion. Under loading conditions, clenbuterol treatment increased all polyamine levels, whereas under unloading conditions, only the spermidine levels were consistently increased. Unloading attenuated the anabolic effects of clenbuterol in predominately slow-twitch muscles (adductor longus), but had little impact on clenbuterol's action as a countermeasure in fast- twitch muscles such as the extensor digitorum longus. Spermidine appeared to be the primary polyamine involved in skeletal muscle atrophy/hypertrophy.
authors.affiliation: Department of Pharmacology and Toxicology, Morehouse School of Medicine, Atlanta, GA 30310-1495, USA. abukhai@msm.edu
authors.forename: Imad K
authors.initials: IK
authors.lastname: Abukhalaf
authors.forename: Daniel A
authors.initials: DA
authors.lastname: von Deutsch
authors.forename: Lawrence E
authors.initials: LE
authors.lastname: Wineski
authors.forename: Natalia A
authors.initials: NA
authors.lastname: Silvestrov
authors.forename: Saare A
authors.initials: SA
authors.lastname: Abera
authors.forename: Sinafikish W
authors.initials: SW
authors.lastname: Sahlu
authors.forename: David E
authors.initials: DE
authors.lastname: Potter
mesh_terms: D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000818:Animals; D015317:Biogenic Polyamines / Q000302:isolation & purification / Q000378:metabolism*; D002976:Clenbuterol / Q000494:pharmacology*; D019417:Hindlimb Suspension; D008297:Male; D018656:Muscle Fibers, Fast-Twitch / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D018657:Muscle Fibers, Slow-Twitch / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D018482:Muscle, Skeletal / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D011700:Putrescine / Q000302:isolation & purification / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013095:Spermidine / Q000302:isolation & purification / Q000378:metabolism
chemical_list: D000318:Adrenergic beta-Agonists; D015317:Biogenic Polyamines; D013095:Spermidine; D011700:Putrescine; D002976:Clenbuterol