ULTRASTRUCTURAL ANALYSIS OF RAT SKELETAL MUSCLE REGENERATION UNDER CHRONIC HYPERGLYCEMIA CONDITION AND USING OF PLATELET-RICH PLASMA

Abstract

Chronic hyperglycemia (CH) is one of the most widespread metabolic disorders worldwide. CH is associated with secondary complications development in skeletal muscle and also may impair its regeneration ability. Platelet-rich plasma (PRP) is one of the promising therapeutic agents capable of enhancing regeneration of various tissues and organs, including striated muscles. Unfortunately, there are no current experiments devoted to revealing the ultramicroscopic effect of PRP on skeletal muscle regeneration under CH influence. The aim of the study was to identify the ultramicroscopic features of post-traumatic skeletal muscle recovery in rats with CH and PRP using. Object and methods. 130 white laboratory male rats divided into four groups (I – control (40 rats); II – rats with CH (40 rats); III – rats with CH and PRP injection (40 rats); IV – rats for CH confirmation (10 rats)) were used for the experiment. CH was simulated by streptozotocin and nicotinic acid administration. Triceps surae muscle injury was reproduced by transverse linear incision. Autologous PRP was used in order to correct the possible negative effect of CH on skeletal muscle regeneration. Ultramicroscopic examination was performed using electron microscope PEM100m (Ukraine, Sumy). The mathematical analysis was done using SPSS software package (v. 17.0). Results. On the 28th day after the injury, weak signs of post-traumatic myogenesis were observed in rats with CH. The muscle fibers were significantly reduced, deformed, and surrounded by a significant layer of connective tissue. Polymorphic nuclei with numerous intussusception, disorganized sarcomeres with ruptured Z-lines were noted in the sarcoplasm. The muscle regenerate of animals with CH and PRP using consisted of massive connective tissue strands, a large number of vessels, and various muscle fibers. The sarcoplasm contained mostly the regularly shaped nuclei, a significant amount of mitochondria in the perinuclear space, and bundles of myofibrils with a wavy and partially ruptured Z-lines Conclusion. The ultramicroscopic analysis revealed a negative effect of CH on the process of skeletal muscle regeneration, which is characterized by the massive development of connective tissue against the background of suppression and imperfect formation of new muscle fibers. The using of PRP in rats with CH improves the process of muscle recovery, shifting it from the development of connective tissue scar towards the formation of a full-fledged muscular organ.

Keywords

• skeletal muscles
• regeneration
• chronic hyperglycemia
• platelet-rich plasma.