engleski

Diabetes Mellitus Type I Causes Changes of Rat Skeletal Muscle

Background and aims. Insulin is a major anabolic hormone in the body, and its deficiency causes diabetes mellitus. It is known that skeletal muscle requires insulin for normal growth and development. Adult skeletal muscle is composed of muscle fibres that differ in their functional and molecular properties. This diversity is based on the pattern of expression of specific myosin heavy chain (MHC) isoforms. Using monoclonal antibodies specific to MHC isoforms, we can distinct two major fibers types: slow contracting fibers, called type I, containing slow MHCs, and three types of fast contracting fibers, called IIA, IIX and IIB muscle fibers. The aim of present study was to investigate the effect of diabetes mellitus type I on skeletal muscle during the four-week period. Material and methods. Two-month old male Wistar rats were randomized to control group and diabetes group. Diabetes was induced by a single streptozotocin (STZ) 65 mg/kg with i.p. injection. At interval of 4 weeks, morphometric analysis (fibre cross areas and fibre type distribution) of skeletal muscles was performed. Results. In diabetic muscles, comparing to normal muscles, the fibre cross areas of all four fibre types (I, IIA, IIX and IIB) were significantly smaller than in normal muscles (P<0.001). There was no difference in the percentage of fibres I, IIA, IIX and IIB in diabetic muscles versus control group after 4 weeks. Conclusion. Diabetic neuromyopathy is charactized with muscle atrophy. Insulin deficiency causes the changes of morphometrical characteristics of skeletal muscle during the diabetes.

diabetes mellitus; skeletal muscle; muscle fibers types

Autor Josip Ažman nagrađen je nagradom za najbolju prezentaciju rada na kongresu.