[The influence of experimental diabetes on the distribution of LDH-isoenzymes in rat skeletal muscle (author's transl)].

The distribution of LDH-isoenzymes from homogenate-supernatant of M. soleus of normal and streptozotocin-diabetic male rats was investigated by agargel-electrophoresis. Five LDH-isoenzymes could be detected in the M. soleus of normal rats; the average proportion of H-subunits was 69.1% (age 3-4 month) resp. 69.6% (age 13 month) from the total value. In male rats of the same age a mild diabetes was induced by intravenous injection of 65 mg streptozotocin per kg body weight. In the M. soleus of these animals also 5 LDH-isoenzymes were detected. After 1-2 month duration of diabetes the LDH1 is decreased from 30.3% of controls to 18.2% and the LDH4 is increased from 11.1% of controls to 20.1%. The H-subunit value decreased to 61.9% from the total value. In long term diabetes (11 month) the values of single fractions and the H-subunit value did not differ from those of controls. The findings are discussed considering the composition of M. soleus on different fiber types and the influence of diabetic conditions.