【摘要】 为阐明肌质网在冬眠动物心肌耐寒适应中的地位，本文对冬眠季和非冬眠季黄鼠心肌肌质网的超微结构和摄钙速率进行了定量对比。（１）在超微结构的研究中，我们采用ＯｓＦｅＣＮ后固定法增加肌质网的着色深度，从而比常规染色更易辨认其结构。（２）形态计量分析结果显示，冬眠黄鼠心肌肌质网和脂滴的体密度显著高于夏季活跃黄鼠，其中肌质同所高出的部分是非连接肌质网。（３）以ａｒｓｅｎａｚｏ－Ⅲ光吸收法测得冬眠黄鼠心肌肌质网的摄钙速率比秋季活跃黄鼠显著升高。上述结果表明，黄鼠冬眠时心肌肌质网的结构和功能得以强化，这可能是冬眠动物心肌耐寒适应中的重要环节。更多还原

【Abstract】 The ultrastructure and calcium uptake rate of the cardiac sarcoplasmic reticulum (SR) was quantatively compared between the ground squirrels (Citellus dauricus in) in hibernating and. non-hibernating season. (1) In our ultrastructural investigation,OsFeCN post-fixation method was used to enhance the staining of SR, which made the SR structure more recognizable. (2) The results of morphometrical analysis demonstrated that the volume density of SR and lipid droplet in the cardio-myocyte was significantly higher (P<0. 01 ) in the hibernating animal than in the summer active one, and the subcompartment of SR with this difference was non-junctional SR. (3) The cardiac SR from hibernating ground squirrels had a higher (P<0. 01) calcium uptake rate as measured by the absorbence of arsenazo-Ⅲ Ca2+ indicator, than that from autumn active ones. Altogether, our results suggested that the function of SR in the uptake of cytosolic calcium was enhanced in hibernating season, which may play an important role in the cold tolerance of myocardium of a hibernator.更多还原