甘肃鼢鼠与SD大鼠骨骼肌低氧适应的比较

运用组织学和紫外分光光度法,对常氧、低氧2周和4周的甘肃鼢鼠(Myospalax cansus)及SD大鼠(Rattus norvegicus)骨骼肌形态结构、乳酸脱氢酶(LDH)、琥珀酸脱氢酶(SDH)活力及肌红蛋白(Mb)浓度进行测定。结果显示,甘肃鼢鼠骨骼肌形态结构在常氧、低氧2周及4周后变化不明显;SD大鼠随低氧时间延长发生显著变化,低氧2周后,肌纤维明显萎缩,间隙增大,结构较紊乱;低氧4周后,肌纤维破裂,呈细丝状,不规则,大小不一致,肌节紊乱。甘肃鼢鼠LDH活性随低氧时间增长逐渐降低,但无显著性差异(P0.05);在不同时间低氧处理后,甘肃鼢鼠前后肢的LDH活性均极显著低于SD大鼠(P0.01);常氧条件下,甘肃鼢鼠前后肢SDH活性低于SD大鼠,但无显著差异(P0.05),低氧2周及4周后,与SD大鼠呈极显著差异(P0.01);常氧条件下,甘肃鼢鼠前后肢Mb浓度均显著高于SD大鼠(P0.05),低氧2周及4周后,极显著高于SD大鼠(P0.01)。结果表明,甘肃鼢鼠骨骼肌较SD大鼠有着更强的低氧耐受力。

Comparison of Skeletal Muscle Hypoxia Adaptation between Gansu Zokor (Myospalax cansus) and SD Rat

Activity of lactate dehydrogenase (LDH) and succinate dehydrogenase (SDH) as well as the concentration of myoglobin (Mb) in Gansu Zokors (Myospalax cansus) and SD rats (Rattus norvegicus) under normoxia,2 weeks and 4 weeks of hypoxia were measured through histological and UV spectrophotometer methods.The results showed no significant difference in Gansu Zokor skeletal muscle morphology among different groups,but a significant morphology change in SD rats was observed;After 2 weeks of hypoxia,the muscle fiber was significantly atrophied,the gap was increased,and the structure was more disordered.After 4 weeks of hypoxia,the muscle fiber was broken down,and sarcomere was disordered.Activity of LDH also showed no difference after different hypoxia adaptations in the Gansu Zokor (P>0.05);but compared to SD rat,activity of LDH in the Gansu Zokor was significantly lower after different hypoxia adaptations (P<0.01).The activity of SDH in the Gansu Zokor was lower than that of SD rat,but with no significant difference (P>0.05),after 2 or 4 weeks of hypoxia,the enzyme activity was significantly lower than that of SD rat (P<0.01).The concentrations of Mb in the Gansu Zokor were higher than those in the SD rat in different hypoxia adaptation groups (P<0.05) (P<0.01).We conclude that Gansu Zokor is much more tolerable to hypoxia than SD rat.