【作者】 党凯；

【导师】 高云芳；

【作者基本信息】 西北大学 ， 动物学， 2007， 硕士

【摘要】 研究背景：废用性肌萎缩会增大卧床病人的康复难度，限制航天员飞行时间和工作效率，威胁航天员在紧急情况下的救生能力。因此，在临床与航天医学中，废用造成的骨骼肌萎缩已成为亟待解决的问题之一。探明骨骼肌萎缩机理与发生途径，从而制定科学的对抗措施不仅对长期卧床病人骨骼肌的防治与康复具有较高的临床应用价值，而且对于航天事业的发展又较大的促进作用，对运动医学的发展亦有借鉴作用。达乌尔黄鼠（Citellus dauricus）作为一种典型的小型冬眠动物，在数月的冬眠过程中，其骨骼肌无疑处于废用状态，但出眠时黄鼠并未发生明显的骨骼肌萎缩现象，如四肢软弱无力、行走困难，甚至不能行走等。因此研究冬眠期间黄鼠比目鱼肌肌纤维类型与收缩功能的变化，既可初步探讨冬眠黄鼠的抗肌萎缩机制，也可为冬眠肌肉生理提供新的研究资料，为预防和治疗废用性肌萎缩提供新思路。目的：观测冬眠期间黄鼠血液流变特性与比目鱼肌肌纤维类型、收缩功能的变化，探讨冬眠对黄鼠比目鱼肌肌纤维类型与收缩功能的影响。方法：（1）采用m-ATP酶组织化学方法测定发育过程中黄鼠比目鱼肌m-ATP酶活性的变化（2）采用快缩型肌球蛋白重链（Myosin heavy chain，MHC）抗体进行免疫组织化学反应，对冬眠不同时期黄鼠比目鱼肌肌纤维进行染色分型。（3）运用Motic Images plus 2.0彩色图像分析软件计数各类型肌纤维数，分析其变化。（4）使用血液粘度仪（YDA-IV（C））等仪器检测冬眠不同时期黄鼠血液流变特性。（5）使用PowerLab系统、电子刺激器（SEN-3301）等仪器测定冬眠不同时期黄鼠比目鱼肌收缩功能结果：（1）幼龄组达乌尔黄鼠比目鱼肌中Ⅱ型肌纤维比例显著高于亚成年组和成年组（P＜0.01），而亚成年组的Ⅱ型肌纤维比例高于成年组（P=0.059）。（2）冬眠期间黄鼠在高(120S^-1)切变率下的全血粘度无明显变化（P＞0.05），而在中(70S^-1)、低(30S^-1)切变率下的全血粘度，冬眠1个月黄鼠与冬眠前黄鼠相比有显著性上升（P＜0.05）；冬眠期间黄鼠血浆粘度和红细胞压积均无显著性变化（P＞0.05）；冬眠1个月和2个月和2.5个月黄鼠红细胞刚性指数平均值与冬眠前黄鼠相比分别上升了0.49％（P＞0.05）、0.62％（P＞0.05）和6.87％（P＞0.05），出眠黄鼠红细胞刚性指数平均为3.358±0.391，高于冬眠前黄鼠，但低于冬眠2.5个月黄鼠（P＞0.05）。（3）冬眠前黄鼠比目鱼肌湿重体重比为0.273±0.041，冬眠1个月、2个月和2.5个月黄鼠分别下降了0.94％（P＞0.05）、7.10％（P＞0.05）和14.56％（P＞0.05），出眠黄鼠为0.225±0.037，与冬眠前黄鼠相比下降了17.54％（P＞0.05），亦无显著性差异。（4）冬眠期间黄鼠比目鱼肌MHCⅠ、Ⅱ型肌纤维比例无显著性变化（P＞0.05）。冬眠1个月、2个月以及2.5个月MHCⅠ型肌纤维比例均高于冬眠前黄鼠，其中冬眠2个月黄鼠增加幅度最大，与冬眠前黄鼠相比增加了6.00％（P=0.092），有增加趋势。而出眠黄鼠MHCⅠ型肌纤维比例亦高于冬眠前黄鼠（P＞0.05），但与冬眠1个月、2个月、2.5个月黄鼠相比有所降低（P＞0.05）。（5）冬眠前黄鼠比目鱼肌等长收缩最大张力（Pt）为（0.114±0.017）（g／mg），与其相比，冬眠1个月升高了10.42％（P＞0.05），冬眠2个月、2.5个月分别下降了1.72％（P＞0.05）、2.62％（P＞0.05），出眠黄鼠与冬眠前相比下降了5.93％（P＞0.05）。与冬眠前黄鼠相比，冬眠1个月、2个月和冬眠2.5个月黄鼠强直收缩最大张力（Po）分别下降了8.08％（P＞0.05）、0.61％（P＞0.05）和5.07％（P＞0.05），而出眠黄鼠则升高了3.57％（P＞0.05）。（6）冬眠过程中黄鼠比目鱼肌达到等长收缩达到最大张力50％的时间(TP₅₀)和达到最大张力时间（TPT）均没有发生显著性变化（P＞0.05），仅有冬眠2个月黄鼠的TPT与冬眠前相比，显示有增加趋势（P=0.078）；而黄鼠比目鱼肌舒张达到最大张力50％的时间(RT₅₀)和舒张达到最大张力75％的时间(RT₇₅)在冬眠过程中均明显性增加（P＜0.05），其中冬眠2.5个月黄鼠的RT₇₅增幅最大，与冬眠前黄鼠相比有极其显著性差异（P＜0.01）。结论：（1）黄鼠在发育过程中，比目鱼肌的Ⅱ型肌纤维比例呈逐渐降低态势，且这种变化主要发生在幼年至亚成年的发育阶段。（2）黄鼠在冬眠过程中血浆粘度、红细胞压积，红细胞刚性指数等血液流变指标并没有发生明显改变，而全血粘度也只有冬眠1个月的黄鼠在中、低切变率下有显著增加。（3）在冬眠过程中黄鼠比目鱼肌的湿重体重比下降，但是比目鱼肌外形上没有表现出明显的肌肉萎缩特征。（4）在冬眠过程中黄鼠比目鱼肌肌纤维会出现MHCⅡ型向MHCⅠ型的转化趋势，并且在出眠后短时间内不会立即恢复到冬眠前状态。（5）冬眠过程中黄鼠比目鱼肌收缩张力没有发生明显改变。（6）冬眠过程中黄鼠比目鱼肌等长收缩时程发生明显变化，而这种变化主要表现为舒张相增加。更多还原

【Abstract】 Background:Therapy of bed-rest sufferer would be more difficult, time and efficiency of work and lifesaving ability of cosmonaut would be limited and threatened because of disused muscle atrophy. Therefore, disused atrophy has become one problem which must be solved urgently. To research the mechanism and reason of muscle atrophy not only have clinic benefit to curing muscle of long bed-rest patient for a long term, but also have important promotion role to spaceflight and sport medicine.Daurian ground squrrel （Citellus dauricus）is a species of typical rodent, its muscle is undoubtely under disused condition during months hibernation. Whereas, arousal from hibenation , ground squrrel whould not present obvious signs of muscle atrophy, such as limb disability, moving difficultly, even can’t moving. Therefore, to study the changes of fibres type and contratile function in ground squrrel soleus muscle during hibernation can prove up mechamism of anti-atrophy of ground squrrel and provide new experimental data for musce physiology of hibernation. In addition, it also may create new ideal for prevention and treatment of muscle atrophy.Objective:Observe the changs of hemorheology, fibers type and contractile function in soleus muscle of ground squrrel during hibernation, study the effcts of hibernation on fibers type and contractile fnction in ground squrrel soleus muscleMethod:The m- ATPase activities in soleus muscle in ground squirrel during postnatal development was detected by m-ATPase histochemical method. （2） Fibre types in ground squirrel soleus muscle during hibernation were identified by immunity histochemistry technology with antibody fast-twitch myosin heavy chain（MHC）. （3） Percentage of fibre types were measured by Motic Images plus 2.0 software. （4） Hemorheology of ground squirrel during hibernation was detected with blood viscosity instrument etc. （5） Contractile function in soleus muscle in ground squirrel during hibernation was observed using PowerLab system and electronical stimulator ,etc.Result:（1） The percentage of type II fibres in soleus muscle in young was obviously higher than in both sub-adult and adult ground squirrel （P<0.01）. Furthermore, The percentage of type II fibres in soleus muscle in sub-adult was higher than that of adult（P= 0.059）.（2） The whole viscosity at high shear rate of ground squirrel during hibernation didn’t show significantly difference. However, the whole viscosity at both middle and low shear rates of ground squirrel of hibernation 1 month（H-lm）ere markedly higher than that of pre-hibernating ground squirrel （P<0.05）. The both plasma viscosity and hematocrit （HCT） of ground squirrel during hibernation didn’t present obviously changes （P>0.05）. In addition, compared with pre-hibernating ground squirrel, the erythrocyte rigidity index （EIR） of individuals of H-1m, hibernation 2 month （H-2m） and hibernation 2.5 month （H-2.5m） increased 0.49%（P>0.05）, 0.62%（P>0.05） and 6.87%（P>0.05）, respectively. The mean EIR of ground squirrel of after hibernation for 1-2 days （AH） was 3.358±0.391, higher than that of pre-hibernating individuals, but lower than that of H-2.5m individuals （P>0.05）.（3） The ratio of soleus muscle weight to body weight of pre-ground squirrel was 0.273±0.041, the ratio of individuals of H-1m, H-2m and H-2.5m decreased 0.94%（P>0.05）, 7.10%（P>0.05） and 14.56%（P>0.05）, respectively. The ratio of AH ground squirrel was 0.225±0.037, decreased 17.54%（P>0.05） compared with pre-hibernating individuals, but there was not significance.（4） The percentage of types I and II MHC fibres in soleus muscle in ground squirrel during hibernation didn’t present significant variation（P>0.05）. However, all the percentages of type I MHC fibres of individuals of H-1m, H-2m and H-2.5m were higher than pre-hibernating squirrel, even the H-2m individuals presented the most increased extent, increased 6.00%（P=0.092）, showed a ascendant tendency. In addition, the percentage of type I MHC fibres of AH individuals was also higher than that of pre-hibernating individuals, but lower than that of individuals of H-1m, H-2m and H-2.5m.（5） The peak isometric twitch tension （Pt） in soleus muscle of pre-hibernating ground squirrel was （0.114±0.017） （g/mg）. The H-1m individuals increased 10.42%（P>0.05）, the individuals of H-2m and H-2,5m decreased 1.72%（P>0.05）, 2.62%（P>0.05）, respectively, furthermore, AH individuals decreased 5.93%（P>0.05）. Compared pre-hibernating ground squirrel, the maximum tetanic tension （Po） of individuals of H-1m, H-2m and H-2.5m decreased 8.08%（P>0.05）, 0.61%（P>0.05）and 5.07%（P>0.05）,respectively. However, AH individuals increased 3.57%（P>0.05）.（6） The time to 50% peak tension (TP₅₀) and time to peak tension （TPT） in ground squirrel soleus muscle during hibernation didn’t present significant difference. Only the TPT of H-2m individuals showed ascendant tendency（P=0.078）. However, the both 50% relaxation time (RT₅₀) and 75% relaxation time （RT75） showed obvious increase（P<0.05）, the RT75 of H-2.5 m individuals especially（P<0.01）.Conclusion（1）The percentage of type II fibres in soleus muscle in ground squirrel during postnatal development presented continuous decrease tendency, furthermore the change happened primarily during the development period of young to sub-adult.（2） The plasma viscosity, HCT and ERI of ground squirrel during hibernation didn’t presented significant changes. However, whole blood viscosity at both middle and low shear rates of H-1m individuals obviously increased.（3） The ratio of soleus weight to body weight of ground squirrel during different hibernation period showed continuous decrease, but soleus muscle didn’t presented marked atrophy characteristics according to its figure. （4） The fibre types in soleus muscle in ground squirrel during hibernation presented the transformational tendency of type IIMHC to type I MHC, furthermore the change wouldn’t come back to the pre-hibernating condition during a short term.（5） The contractile tension in soleus muscle in ground squirrel during hibernation didn’t present significant change.（6） The obvious change of isometric twitch during in soleus muscle in ground squirrel happened during hibernation, furthermore the change showed primarily the sign of relaxation time increase.更多还原