FROM:
Acta Histochem 1999 (Feb); 101 (1): 53–69
Punkt K, Psinia I, Welt K, Barth W, Asmussen G
Institute of Anatomy, University of Leipzig, Germany
Combined cytophotometric and morphometric
analysis of muscle fibre properties and myosin heavy chain
electrophoresis were performed on extensor digitorum longus
and soleus muscles from healthy rats and rats with
streptozotocin–induced diabetes. Moreover, the protective
effect of Ginkgo biloba extract, a potent oxygen radical
scavenger, on diabetic muscles was investigated. Changes in
fibre type–related enzyme activities, fibre type
distribution, fibre cross areas and myosin isoforms were
found. In muscles of diabetic rats, a metabolic shift was
measured mainly in fibres with oxidative metabolism.
Fast–oxidative glycolytic fibres showed a shift to more
glycolytic metabolism and about a third transformed into
fast–glycolytic fibres. Slow–oxidative fibres became more
oxidative. Fibre atrophy was measured in diabetic muscles
dependent on fibre type and muscle. Different fibre types
atrophied to a different degree. Therefore, a decreased area
percentage of slow fibres and an increased area percentage
of fast fibres of the whole muscle cross section in both
muscles were found. This is supported by reduced slow and
increased fast myosin heavy chain isoforms. These
alterations of diabetic muscle fibres could be due to less
motion of diabetic rats and diabetic neuropathy. After
treatment with Ginkgo biloba extract, enzyme activities were
increased mainly in oxidative fibres of diabetic muscles,
which was interpreted as protective effect. Generally, the
soleus muscle with predominant oxidative metabolism was more
vulnerable to diabetic alterations and Ginkgo biloba extract
treatment than the extensor digitorum longus muscle with
predominant glycolytic metabolism.
![[SWIRL 2]](../GRAPHICS/SWIRL-2.GIF)