The regeneration of skeletal muscles is a suitable model to study the development and differentiation of contractile tissues. Neural effects are one of the key factors in the regulation of this process. In the present work, effects of different reinnervation protocols (suture or grafting) were studied upon the regenerative capacity of rat soleus muscles treated with the venom of the Australian tiger snake, notexin, which is known to induce complete necrosis and subsequent regeneration of muscles. Morphological and motor endplate analysis indicated that the regenerative capacity of denervated, and thereafter surgically reinnervated muscles remains impaired compared to that of normally innervated muscles, showing differences in the muscle size, fiber type pattern and motor endplate structure, even 35 days after the notexin injection. A lack or deficiency of secreted neural factors, deterioration of satellite cells and/or incomplete recovery of the sutured or grafted nerves may be the cause of these discrepancies in the regeneration process.
The aim of the study was to observe the effect of coenzyme Q10 and vitamin E supplementation on the course of the regeneration process of the longissimus lumborum muscle after bupivacaine-induced myonecrosis as well as to determine the correlation between the level of those substances in plasma and their levels in damaged and non-damaged muscular tissue in pigs. The obtained results indicate that the course of regeneration of a damaged muscle is affected to a higher extent by coenzyme Q10 than by vitamin E. The administration of coenzyme Q10 and vitamin E has a significant impact on the increase in the level of those substances in damaged muscles and plasma of animals.
Calpains — non-lysosomal intracellular calcium-activated neutral proteinases, form a family consisting of several distinct members. Two of the isoenzymes: ji (calpain I) and m (calpain II) responded differently to the injury during complete regeneration of Extensor digitorum longus (EDL) muscle and partial regeneration of Soleus muscle. In the crushed EDL the level of m-calpain on the 3rd and 7th day of regeneration was higher than in non-operated muscles, whereas the activity of this calpain in injured Soleus decreased. The level of n-calpain in EDL oscillated irregularly during regeneration whereas in Soleus of both injured and contralateral muscles its level rapidly rose. Our results support the hypothesis that m-calpain is involved in the process of fusion of myogenic cells whereas u-calpain plays a significant but indirect role in muscle regeneration.
The aim of this study was to identify the genetic changes in rye seeds induced by natural aging during long-term storage and successive regeneration cycles under gene bank conditions. Genomic DNA from four rye samples (cv. Dańkowskie Złote), varying in their initial viability and having gone through one or three reproduction cycles, were analysed using specific PCR targeting of a secalin locus, and various repetitive fragments defined by the R173 sequence. A statistical analysis of the band frequencies for both secalin and R173.3 primer pairs revealed no changes in their frequencies. Similar data on R173.1 demonstrated significant changes between samples of different initial viability showing a lack of a band of the expected length (987 bp) in progeny originating from low viability seeds lots. These changes were inherited even after three regeneration cycles. Our results may indicate that long-term storage that leads to loss of viability also generates heritable changes in the preserved germplasm. However, it remains to be discovered where these changes occur and whether they are connected with coding or with non-coding DNA regions.