MYOCARDIAL METABOLISM OF RATS LOADED WITH VARIOUS INTENSITIES AND DURATIONS OF EXERCISE
- Author:
SUKETSUNE IWAGAKI
- Publication Type:Journal Article
- From:Japanese Journal of Physical Fitness and Sports Medicine
1975;24(3):91-100
- CountryJapan
- Language:English
-
Abstract:
Rats were loaded with exhaustive running by means of the treadmill at speeds of 15, 25, 35 and 40m/min, and relation between levels of the right ventricular blood substances and of myocardial energy sources was examined in reference to the intensity and duration of exercise. Moreover, when made to run at 25m/min, rats were sacrificed at 5, 15, 30 and 45 minutes to observe the above mentioned relation in the course of time.
1. In case of exhaustion produced by running at 40m/min, both myocardial glycogen and triglyceride increased while blood sugar and serum FFA markedly depleted. In rats of exhaustion produced by running at 35m/min, myocardial glycogen and blood sugar decreased to the lowest level. Also, at 15m/min, both myocardial glycogen and trigly-ceride decreased. At this time, blood sugar decreased to 50mg/dl, while serum FFA showed increase.
2. An antagonistic relation was observed between myocardial and serum phospholipid levels. Thus, when exercise intensity was high, myocardial phospholipids decreased while serum phospholipids increased. When the speed was 15m/min, the relation was reversed; i.e. myocardial phospholipids increasing while serum phospholipids decreasing.
3. In the myocardial metabolic process during the running at 25m/min, myocardial triglyceride and plasma FFA depleted rapidly irrespective of change in blood sugar and myocardial glycogen level. When the speed was 25m/min, myocardial glycogen increased at 5min after the start of running.
4. On the basis of these results, myocardial metabolism during the exercise was discussed.
