Abstract
The aim of the present investigation has, been to evaluate the depletion pattern of the supercompensated glycogen of hindlimb muscles during strenous exercise in rats. The plan of the maximizing muscle glycogen stores is based on the fact that a glycogen-depleted muscle by exercise will have an increased avidity for glycogen when exposed to a high carbohydrate diet. The glycogen concentration of soleus, red gastrocnemius and plantaris muscle, and liver was measured at 0, 30 and 60 minutes during treadmill exercise. The experimental animals were divided into 5 group - Normal(N), Control(C), 1Hour(1HR:after 1hour of glucose ingestion), 2Hour(2HR:after 2hour of glucose ingestion) and Exercise-1Hour(EX-1HR:glucose ingestion after 1 hour of preloading treadmill exercise)group - for glycogen storage study. The glycogen concentration of soleus, red gastrocnemius and plantaris muscles in N group was $4.57{\pm}0.34$, 5.11+0.24 and $6.55{\pm}0.20mg/gm\;wet\;wt.$, respectively. The glycogen concentration of soleus and red gastrocnemius in EX-1HR group were about 1.9 and 1.8 times than that of N group, respectively, but the concentration of plantaris was not higher than that of N group. The glycogen concentration of liver in N group was $41.0{\pm}1.47mg/gm\;wet\;wt.$ and the concentration of the overnight fasted C group was only 2.9% of the value of N group. The level of glycogen concentration of liver in the other glucose ingested groups(1HR, 2HR, including EX-1HR) was within 19 - 32% of that of N group. The blood glucose concentration of EX-1HR group was higher than that of N group, the plasma free fatty acid concentration of C and 2HR group was higher than that of N group, and the plasma insulin concentration of EX-1HR group was higher than that of N group. The concentrations of supercompensated glycogen of soleus and red gastrocnemius were rapidly decreased during 30 minutes of exercise but there was almost no changes of the concentration during the other 30 minutes of continuing exercise. The concentration of N group during 30 minutes of exercise was decreased but more slowly than those of EX-1HR group. The remaining level of glycogen after 60 minutes of exercise in EX-1HR group was higher than that of N group. Taken together, the mobilization of endogenous muscle glycogen at the first stage of exercise was proportioned to the initial level of glycogen concentration, and later on, when exercise continued, the muscle glycogen level was stabilized. And the remaining level of supercompensated muscle glycogen after 60 minutes of exercise was higher than that of normally stored glycogen level. The mobilization of the glycogen stroed in slow and fast oxidative muscle fibers is faster than in the fast glycolytic muscle fibers during strenous exercise.
골격근의 과축적 당원의 운동 중 이용 양상과 골격근의 구성 섬유 특성에 따른 당원의 이용 양상을 규명한 본 연구 결과를 요약하면 다음과 같다. 정상 군의 당원 농도는 가자미근에서 $4.57{\pm}0.34mg/gm\;wet\;wt.$(이하 동일 단위)였으며 적색 비복근은 $5.11{\pm}0.24$, 족척근은 $6.55{\pm}0.20$으로서 족척근이 가장 높았다. 가자미근의 당원 농도는 운동 부하 후 당투여 1시간 군에서 정상 군에 비해서 약 1.9배 높았으며 적색 비복근은 1.8배 높았다. 족척근의 당원 농도는 운동 후 당 투여 군에서 정상 군과 통계적으로 유의한 차이가 없었다. 각 당원 농도는 정상군에서 $41.0{\pm}1.47$이였으며 대조 군에서는 정상군의 2.9%에 불과했으나 당투여 1시간, 2시간 및 운동 부하 후 당투여 1시간 군등 모든 군의 당원농도는 정상 군의 19 - 32%의 범위 내에 있었다. 혈당 및 인슐린은 운동 부하 후 당 투여 군에서 가장 높았으며 유리 지방산은 대조군 및 당투여 2시간군에서 높았다. 운동 부하 중 가자미근 및 적색 비복근의 당원감소는 초 과축적 당원군, 과축적군 및 정상 군에서 다같이 운동 부하 첫 30분에 급격하였으나 초 과축적군에서 더 급격하였다. 운동 부하 30분에서 60분 사이에는 초 과축적군 및 정상 군에서 다같이 당원 감소는 거의 없었으나 과축적군에서는 지속적인 감소 상을 보였다. 간 당원은 정상 군에서 가장 급격한 감소를 보였으며 골격근과는 달리 운동 부하 60분간 지속적으로 감소하였다. 초 과축적당원군의 간 당원 농도는 변화가 없거나 증가하는 경향이었다. 운동 부하 중 혈당은 모든 실험군에서 감소하였으며 인슐린은 운동 부하 후 당투여 군에서 감소하였다. 혈중 유리 지방산 농도는 모든 군에서 증가하였으며 운동 부하 후 당투여 군에서 가장 낮았다.