Macro-Microscopic Features of the Leg Muscles Innervation

The purpose of the study was to disclose topographic anatomical features of the extra- and intramuscular innervation points of the leg. Materials and methods. 15 adult human subjects and one-month old baby legs at three levels were studied using such methods: cross-sections according to N.I. Pirogov technique, histotopographic sections, macro-microscopic method, histological staining with hematoxylin-eosin and Krutsay. Results. In our macro-microscopic study, the main attention was paid to the individual anatomical variability in the innervation of the lower leg muscles. Study of the nerves of the leg muscles allowed to clarify the course of the neurovascular bundle of the leg at its three levels, taking into account individual age characteristics, and also to show the myeloarchitectonics of both the main nerve trunks and their intramuscular branches. Such differences in the location of the leg muscles of an adult and of one month-old baby undoubtedly related to the fact that the child’s muscular belly is longer in relation to the tendon. The histotopography of intramuscular nerves on total transverse sections of antagonistic muscles was studied: flexor and extensor digitorum longus, longus flexor and extensor of the big toe, and also the spectrum of myelin fibers contained in these nerves in a one-month-old baby and an adult was investigated. On histotopographic sections of the extensor digitorum longus nerve in a one-month-old baby, thick-diameter myelin fibers are absent, whereas in the long finger flexor nerve, on average, they are 0.5%. The number of thin and medium is respectively 8%, 13% and 83.5%, 16%. However, we have determined individual anatomical variability in the location of the vessels in relation to the main nerve trunks, as well as differences in the topography of the nerve in the corresponding muscles. Conclusion. In the nerves of the leg muscles, features were found, both in quantitative and qualitative composition of the conductors forming them; in the nerves of the flexor muscles, the composition of the nerve fibers is more diverse (with a slight predominance of the number of medium, thick and very thick fibers), which is associated with the peculiarity of their functions; in adulthood, the % ratio in the spectrum of myelin fibers in the nerves of the lower leg changes significantly

Antihyperglycemic Activity of Aqueous Extract of Euphorbia guyoniana in Streptozotocin-Induced Diabetic Rats

Aims: This work assessed the antihyperglycemic effect of Euphorbia guyoniana. Background: Euphorbia guyoniana (Boss. and Reut.) is widely used in traditional medicine. Objective: This study was designed to confirm this traditional use by assessing its antihyperglycemic capacity in vivo. Methods: The effect of the aqueous extract of Euphorbia guyoniana (Boss. and Reut.) (60 mg/kg) on glycemia in both normal and diabetic rats was evaluated. The glycogen content in the liver and skeletal muscles (extensor digitorum longus and soleus) was measured. Furthermore, liver histopathological analysis was performed. Results: The findings showed that Euphorbia guyoniana (Boss. and Reut.) exhibited a significant decrease in glycaemia in diabetic rats (from 20±2 mmol/l to 5.5 mmol/l after 6 hours of oral administration; p<0.0001 and from 20±2 mmol/l to 4.5 mmol/l after 7 days of once-daily repeated oral administration of the aqueous Euphorbia guyoniana extract; p<0.0001). In addition, the extract increased the glycogen content in the liver (41±4 mg/g versus 70±5 mg/g in normal and diabetic rats respectively) and extensor digitorum longus (39±4 mg/g versus 60±1 mg/g in normal and diabetic rats, respectively), and partially restored corporal weight in diabetic rats. Furthermore, this aqueous extract has been shown to suppress hyperglycemia induced by glucose load in treated diabetic rats. Additionally, hepatic histology in diabetic rats has been improved. This plant revealed the presence of several phytochemical constituents and possessed antioxidant activity. Conclusion: The current study evidenced that Euphorbia guyoniana (Boss. and Reut.) has a beneficial effect on improving hyperglycemia and glycogen depletion in the diabetic state.

Effect Mechanism of Electroacupuncture at ST36 on the Injured Extensor Digitorum Longus in the Jumping Rat Model Based on mRNA-Seq Analysis

The key target and regulatory mechanism of electroacupuncture of Zusanli (ST36) on extensor longus muscle injury in a jumping rat model were investigated. To this end, 24 female SD rats were randomly divided into the following four groups: no-treatment control group (NON), 6-week jumping group (J6O), electroacupuncture group after 6-week jumping (J6A), and natural recovery group after 6-week jumping (J6N). After 6 weeks of jumping, in the electroacupuncture group (J6A), electroacupuncture stimulation was applied at Zusanli(ST36) for 20 min per day over the course of 5 days. In the natural recovery group (J6N), rats were fastened with a special apparatus without electroacupuncture stimulation for 20 min at the same time. Transmission electron microscopy, transcriptome sequencing and analysis, Western blotting assay and immunofluorescence staining were performed at the end of our experiment. The recovery effect of J6A rats was more obvious than that of J6N rats and J6O rats as indicated by changes of infiltration of inflammatory cells and morphological structure. Notably, the morphological structure of J6A rats was closer to NON rats in the observation of transmission electron microscopy. CISH/STAT3 regulation was identified by mRNA-seq. The pro-inflammatory response to STAT3 activation was alleviated through up-regulating the expression of CISH protein in J6A rats relative to J6O rats. The level of BAX was decreased and the level of Bcl-2 level was increased in J6A rats relative to J6O rats. Moreover, when compared to J6N rats, the level of Bcl-2 was significantly up-regulated in J6A rats. Increased caspase-3 expression but decreased CDKN2α expression was shown in J6A rats relative to NON rats. These results indicate that the potential mechanism underlying electroacupuncture stimulation of Zusanli (ST36) in repairing the injured extensor digitorum longus following overused jumping may be attributed to CISH/STAT3 regulation of proteins associated with inflammation, apoptosis, and proliferation.

Measurement of Lateral Transmission of Force in the Extensor Digitorum Longus Muscle of Young and Old Mice

The main function of skeletal muscles is to generate force. The force developed by myofiber contraction is transmitted to the tendon. There are two pathways of force transmission from myofibers to tendons: longitudinal transmission that depends on tension elicited via the myotendinous junction and lateral transmission that depends on shear elicited via the interface between the myofiber surface and surrounding connective tissue. Experiments using animal muscle and mathematical models indicated that lateral transmission is the dominant pathway in muscle force transmission. Studies using rat muscle showed that the efficiency of lateral force transmission declines with age. Here, the lateral transmission of force was measured using the extensor digitorum longus muscle from young and old mice. Dependence on longitudinal transmission increased in the old muscle, and there was a trend for lower efficiency of lateral force transmission in the old muscle compared to the young muscle. There was a noticeable increase in the connective tissue volume in the old muscle; however, there was no significant change in the expression of dystrophin, a critical molecule for the link between the myofiber cytoskeleton and extracellular matrix. This study demonstrates the measurement of lateral force transmission in mouse muscles and that alteration in force transmission property may underlie age-related muscle weakness.

Effects of microgravity exposure and fructo-oligosaccharide ingestion on the proteome of soleus and extensor digitorum longus muscles in developing mice

Short-chain fatty acids produced by the gut bacterial fermentation of non-digestible carbohydrates, e.g., fructo-oligosaccharide (FOS), contribute to the maintenance of skeletal muscle mass and oxidative metabolic capacity. We evaluated the effect of FOS ingestion on protein expression of soleus (Sol) and extensor digitorum longus muscles in mice exposed to microgravity (μ-g). Twelve 9-week-old male C57BL/6J mice were raised individually on the International Space Station under μ-g or artificial 1-g and fed a diet with or without FOS (n = 3/group). Regardless of FOS ingestion, the absolute wet weights of both muscles tended to decrease, and the fiber phenotype in Sol muscles shifted toward fast-twitch type following μ-g exposure. However, FOS ingestion tended to mitigate the μ-g-exposure-related decrease in oxidative metabolism and enhance glutathione redox detoxification in Sol muscles. These results indicate that FOS ingestion mildly suppresses metabolic changes and oxidative stress in antigravity Sol muscles during spaceflight.

Anatomical Variations of the Peroneus Tertius and Extensor Digitorum Longus Muscles – Case Presentation

Introduction: The extensor digitorum longus and peroneus tertius muscles have multiple morphological variations. The tendinous slips of these muscles are used as grafts to replace other damaged tendons. Case presentation: We present a unique anatomical variant observed during dissection of a cadaver at the Department of Anatomy and Embryology of the “George Emil Palade” University of Medicine, Pharmacy, Science and Technology of Târgu Mureș, Romania. The peroneus tertius muscle was identified on the left lower extremity as originating from the inferior third of the fibula and interosseus membrane. The posterior belly of this muscle joins the muscular belly of the extensor digitorum longus muscle. The tendons of toes II to V detach from the extensor digitorum longus muscle with an additional tendon. This last tendon gives off an accessory tendinous slip; lateral to this, the peroneus tertius muscle tendon is observed. In case of the right lower limb we also noted the peroneus tertius muscle originating from the distal part of the extensor digitorum longus muscle. Regarding the extensor digitorum longus muscle we describe an accessory tendinous slip. Conclusion: The anatomical variation reported in this study is similar to those reported by previous studies, but displays particular characteristics regarding the VI tendon of extensor digitorum longus and the joining of the peroneus tertius and extensor digitorum longus muscles in the left lower extremity.