Abstract

The activities of prolyl 4-hydroxylase (PH) and galactosylhydroxylysyl glucosyltransferase (GGT), both enzymes of collage biosynthesis, and the concentration of hydroxyproline (Hyp) were measured in soleus and tibialis anterior muscle after periods of 0, 7 and 21 days of immobilization following a swimming training for a period of three weeks in rats. After swimming, the specific activities of PH and GGT were increased by 25 and 53, respectively, in the soleus muscle. In the tibialis anterior muscle PH was increased by 31 after exercise. During the first week of immobilization, PH activity in the shortened soleus muscle was decreased by 21 and by 65 below the control level in the trained and non-trained groups, respectively. The difference between these two groups is significant. The specific activity of PH decreased to control level after one week of immobilization in the tibialis anterior muscle. Hyp concentration increased significantly in the shortened soleus muscle after one week of immobilization due to rapid atrophy of non-collagenous proteins, whereas in the tibialis anterior muscle no significant increase was observed until after three weeks of immobilization. Verf.-Referat