[Reloading of rat soleus after hindlimb unloading and serum insulin-like growth factor 1].
The aim of this study was to elucidate the effects of 14- day hindlimb suspension (HS) and subsqquent reloading (3 or 7 days) on the m. soleus mass, muscle fiber cross-sectional area (CSA), soleus fiber properties and serum IGF-1 in rats. Rats were hindlimb suspended for 14 days or kept as controls (C, n = 7). Soleus muscles were isolated after HS (HS, n = 7) or after reambulation for either three (R3, n = 5) or seven days (R7, n = 6). Frozen serial sections of m. soleus were stained by primary monoclonal antibodies against MHCI. For measurement of concentration IGF-1 in the blood serum, test-system for IFA DSL-10-2800 Non-Extraction IGF-1 ELISA was used. Muscle mass was significantly reduced in HS (-35 %) but subsequently increased with reloading in R3 (-10 % to C) and was recovered to control values in R7 (+5 % to C). Fiber CSA was significantly reduced (-43 %) in HS and was greater in R7 than in HS and slightly greater than in R3. 14 days of HS resulted in a mean maximal tension reduced by 35 %. After 7 days of subsequent reloading the mean maximal specific tension was still low (-33 % to C) and didn't differ from HS level. The level in blood IGF-1 has obviously decreased during 14-day unloading by 48 %, remained at the same level in R3, and increased 10 fold in R7.
Litvinova
K S
KS
Tarakin
P P
PP
Fokina
N M
NM
Istomina
V E
VE
Larina
I M
IM
Shenkman
B S
BS
D000818:Animals; D019417:Hindlimb Suspension; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D008297:Male; D009119:Muscle Contraction; D018482:Muscle, Skeletal / Q000378:metabolism* / Q000473:pathology; D009133:Muscular Atrophy / Q000097:blood* / Q000209:etiology; D051381:Rats; D017208:Rats, Wistar
D007334:Insulin-Like Growth Factor I