The Primary Research On The Structure And Function Of Mitocondria During The Hibernation In Ground Squirrel (Spermophilus Dauricus)

Objective:1. To study the changes of the Mitochondria morphological structure of soleus (SOL) and extensor digitorum longus (EDL) during different phases of hibernation of ground squirrel (Spermophilus Dauricus).2. To study the activity of the Mitochondrial Cytochrome C Oxidase (COX) of SOL and EDL during different phases of hibernation of ground squirrel(Spermophilus Dauricus).3. To study the concentration of Calcium (Ca2+) in the Mitochondria matrix of SOL and EDL during different phases of hibernation of ground squirrel (Spermophilus Dauricus).Methods:1. The changes of the Mitochondria morphological structure in SOL and EDL were observed by using the scanning electron microscopy technology.2. The COX activity of SOL and EDL were determined by using UV spectrophotometer.3. The concentration of Calcium (Ca2+) in the Mitochondria matrix of SOL and EDL were determined by using the colorimetric method of Methylthymol Blue (MTB).Results:1. The changes of the Mitochondria morphological structure of soleus (SOL) and extensor digitorum longus (EDL) during different phases of hibernation:1) Compared with Pre-H group and Post-H group, In-H Group mitochondrion-rich phenomenon (MRP) not only displays generally and significantly, and also appears frequently around the blood capillary;2) Compared with intra spindle muscle, extra spindle muscle displays more obvious mitochondria-rich phenomenon;3) The Z line of muscle fiber distributes the coupled mitochondrion, of which the internal structure is clear, complete, and the mitochondrion show indistinctive degenerative changes;4) Compared with the Previous-Hibernation group (Pre-H) and the Posterior-Hibernation group (Post-H), the In-Hibernation group degree of mitochondria-rich phenomenon of the muscle fibers in SOL and EDL is the most obvious. Compared with the Previous-Hibernation group, the In-Hibernation group (In-H) MRP proportion of SOL and EDL muscle fibers shows an increment of 45.81% and 60.91%(P＜0.05); the Posterior-Hibernation group MRP proportion of SOL and EDL muscle fibers is compared to that of the Previous-Hibernation group with a decrement of 31.18% and 57.52%(P<0.05); However, the MRP proportion of SOL and EDL muscle fibers show no significant difference between the Previous-Hibernation group and the Posterior-Hibernation group(P>0.05).2. In different periods of hibernation, the COX activity of SOL and EDL muscle fibers shows differences, but the general trend is very similar. During SOL and EDL muscle fibers of In-Hibernation group, the COX activity is the highest, and shows significant difference compared with the Previous-Hibernation group and the Posterior-Hibernation group(P<0.05)The COX activity of SOL underwent two months of hibernation was increased by 72.03% (P<0.05), compared with the Previous-Hibernation. The COX activity of SOL in the Posterior-Hibernation (one to two days) showed a decrement of 61.69%(P<0.05). And the COX activity of EDL underwent two months of hibernation increased by 97.01%(P<0.05), compared with the Previous-Hibernation. The COX activity of EDL in the Posterior-Hibernation (one to two days) indicated a decrement by 62.83%(P<0.05). However, the COX activity of SOL and EDL shows no significant difference between the Previous-Hibernation group and the Posterior-Hibernation group (P>0.05).4. the concentration of Calcium (Ca2+) in the Mitochondria matrix of SOL and EDL filbers during different phases of hibernation:Compared with the Previous-Hibernation group, the In-Hibernation group and the Posterior-Hibernation group of ground Squirrel's degree of Calcium (Ca2+) in the Mitochondria matrix of the muscle fibers in SOL and EDL increases by 12.61% and 18.26%, yet the concentration of Ca2+ in Posterior-Hibernation group decreases approximately back to the level of Previous-Hibernation group. Compared with the Control Rat group(Control-Rat), the concentration of Ca2+ in the Hindlimb-unloading rat group(HLU-Rat) of SOL and EDL muscle fibers shows an increment of 54.22% and 69.33%(P＜0.05)...