title: Preventive effects of nucleoprotein supplementation combined with intermittent loading on capillary regression induced by hindlimb unloading in rat soleus muscle.
abstract: Physical inactivity leads to muscle atrophy and capillary regression in the skeletal muscle. Intermittent loading during hindlimb unloading attenuates the muscle atrophy, meanwhile the capillary regression in the skeletal muscle is not suppressed. Nucleoprotein has antioxidant capacity and may prevent capillary regression. Therefore, we assessed the combined effects of intermittent loading with nucleoprotein supplementation on capillary regression induced by hindlimb unloading. Five groups of rats were assigned: control (CON), 7 days hindlimb unloading (HU), HU plus nucleoprotein supplementation (HU + NP), intermittent loading during HU (HU + IL), and intermittent loading combined with nucleoprotein supplementation during HU (HU + IL + NP). Seven days HU resulted in decrease in capillary number-to-fiber number (C/F) ratio accompanied with disuse-associated changes in fetal liver kinase-1 (Flk-1), a proangiogenesis factor, and thrombospondin-1 (TSP-1), an antiangiogenesis factor, in the soleus muscle. In addition, citrate synthase (CS) activity was decreased and protein level of superoxide dismutase (SOD)-2 was increased. Neither nucleoprotein supplementation nor intermittent loading prevented the decrease in the C/F ratio, whereas nucleoprotein supplementation combined with intermittent loading prevented the regression of capillary during unloading. Moreover, the levels of Flk-1, TSP-1, and SOD-2 protein and the CS activity were maintained up to control levels. These results suggested that nucleoprotein supplementation combined with intermittent loading was effective to prevent capillary regression induced by muscle atrophy.
authors.affiliation: Department of Rehabilitation Science, Kobe University Graduate School of Health Sciences, Kobe, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Hirayama
authors.affiliation: Department of Rehabilitation Science, Kobe University Graduate School of Health Sciences, Kobe, Japan.
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Nakanishi
authors.affiliation: Department of Rehabilitation Science, Kobe University Graduate School of Health Sciences, Kobe, Japan.
authors.forename: Noriaki
authors.initials: N
authors.lastname: Maeshige
authors.affiliation: Department of Rehabilitation Science, Kobe University Graduate School of Health Sciences, Kobe, Japan fujino@phoenix.kobe-u.ac.jp.
authors.forename: Hidemi
authors.initials: H
authors.lastname: Fujino
mesh_terms: D000818:Animals; D002196:Capillaries / Q000187:drug effects* / Q000378:metabolism; D002950:Citrate (si)-Synthase / Q000378:metabolism; D019417:Hindlimb Suspension; D008297:Male; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000378:metabolism; D009133:Muscular Atrophy / Q000378:metabolism; D009698:Nucleoproteins / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013482:Superoxide Dismutase / Q000378:metabolism; D019700:Thrombospondin 1 / Q000378:metabolism
chemical_list: D009698:Nucleoproteins; D019700:Thrombospondin 1; D013482:Superoxide Dismutase; D002950:Citrate (si)-Synthase
keywords: Capillary regression; intermittent loading; nucleoprotein; skeletal muscle