Effects of high +Gx exposure after simulated weightlessness stimulation on the expression of RyR1 mRNA in masseter muscle of Rhesus macaque
GONG Wen-ting
NIU Zhong-ying
TANG Chu-hua
ZHENG Yan-hua
SI Shao-yan
Bao Bo
Chen Yu-hui
Abstract：AIM:To study the effects of high +Gx exposure after simulated weightlessness on RyR1 mRNA expression in masseter muscle of Rhesus macaque.METHODS:23 male Rhesus macaques were randomly divided in-to 4 groups:control (A),simulated weightlessness (B),simulated overweight (C)and high +Gx exposure after sim-ulated weightlessness (D)groups.Group D was further divided into 4 subgroups according to the Gx loads and dura-tion,including +11Gx/270s (D1),+13Gx/230s (D2),+15Gx/200s (D3)2 and 10 day recovery after exposure in +13Gx/230s (D4)groups.Masseter muscle was sampled and obsserved by HE staining and RT-PCR.RE-SULTS:Histopathological observation showed that the sarcolemma of the experimental groups exhibited fuzzy bounda-ries.The striation were not clear or disappeared.Interstitial space was slightly sparse and some muscle cells were swol-len.Occasionally nucleus were flat or shifted in the center.RyR1 mRNA expression in masseter muscle of group B, group C,group D1,D2 and D3 was significantly decreased (P<0.05).RyR1 mRNA expression in D2 and D3 groups was significantly lower than in control group (P<0.05).However,RyR1 mRNA in D4 group was significantly higher than that in D2 group (P<0.05 ).CONCLUSION:Simulated weightlessness,simulated overweight and high +Gx exposure after simulated weightlessnes tested in this study can cause pathological changes and down-regulate RyR1 mR-NA expression in masseter muscle cells of Rhesus macaque.The changes are reversibe.
Keywords：simulated weightlessnessoverweightmasseter muscleRyR1
Publication Date：2014-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：5( 437-441 )