Details

Autor(en) / Beteiligte

• Kovanen, Vuokko

Titel

Effects of ageing and physical training on rat skeletal muscle: An experimental study on the properties of collagen, laminin, and fibre types in muscles serving different functions

Ort / Verlag

ProQuest Dissertations Publishing

Erscheinungsjahr

1989

Link zum Volltext

Quelle

ProQuest Dissertations & Theses A&I

Beschreibungen/Notizen

• The purpose of the present investigation was to study the effects of both advancing age and life-long endurance training on the connective tissue and fibre composition of two types of rat skeletal muscle. In particular, additional evidence was sought on age- and training-induced transformations of muscle fibres, and on the significance of intramuscular collagen in muscle functioning. For this purpose a combined study of exercise and aging throughout the life-span of the experimental animals was constructed. To gain a broad view of muscle responsiveness the muscle fibre types, the estimates of different biochemical and histological properties of collagen as well as of the passive mechanical properties of both a slow (m. soleus = MS) and a fast (m. rectus femoris = MRF) skeletal muscle were determined. The results can be summarized as follows: Long-term endurance training used did not reverse the age-related shift in muscle fibre composition but clearly accelerated the fibre transformation towards more fatigue-resistant muscle fibres with slower contractile speeds. The slow postural soleus contained more collagen compared with the fast locomotor rectus femoris muscle. Both advancing age and life-long endurance training appeared to further distinguish the slow-twitch and fast-twitch muscles with respect to their connective tissue and material properties. Endurance-type activity maintained throughout life did not counteract the age-related changes in the behaviour of muscle collagen. The higher collagen concentration in the continuously contracting slow soleus muscle and the restriction of the endurance training-induced increase in collagen to the soleus muscle suggest indirectly that the regulation of collagen biosynthesis is dependent on muscle contractile activity. (Abstract shortened by UMI.)