Diabetes induces compositional, structural and functional alterations on rat skeletal soleus muscle revealed by FTIR spectroscopy: a comparative study with EDL muscle

摘要

Diabetes Mellitus (DM) is a metabolic disorder, characterized by abnormally high blood glucose levelsndue to decreased secretion or effectiveness in function of insulin. Having a role in carbohydrate andnlipid metabolism, skeletal muscle is affected by the absence of insulin in diabetic conditions. Thisncurrent study reports the application of Fourier transform infrared (FTIR) spectroscopy in thendetermination of macromolecular alterations in streptozotocin (STZ)-induced diabetic rat skeletalnSoleus (SOL) muscles, which highlight the promise of this technique in medical research. The resultsnrevealed that DM induced several alterations in macromolecular content and structure of slowcontractingnSOL muscles. In diabetic SOL muscles, a decrease in the content of lipids, proteins andnnucleic acids together with an increase in lipid order was observed. The decrease in the level ofnunsaturation and acyl chain length of lipids demonstrated the increased lipid peroxidation in DM.nThere were alterations in protein secondary structure in DM with a decrease in a-helix and b-sheetncontent of proteins, whereas the content of aggregated b-strands increased, which is generally seennwhen proteins denature. Besides, the integrity of collagen molecules was found to be decreased,ndemonstrating the alterations in its triple helical structure in diabetic muscles. Furthermore, the samenalterations mentioned above were also observed in diabetic fast-contracting Extensor DigitorumnLongus (EDL) muscles. However, having a high content of mitochondria and relying on an oxidativenpathway, SOL muscle was found to be more affected by DM.