Histopathological examination of 12 vocal muscles reveals special structure of this muscle which the vocal folds are based upon. The bundles of the muscle fibres passing in two planes perpendicular to each other alternate with stripes of the interstitium, seromucinous glandules and connective tissue septa with elastic fibres separating the groups of cross-striated muscle fibres of various diameters. It represents a physiological variety of the skeletal muscle structure conditioned by its function.

• MeSH
• dospělí MeSH
• laryngální svaly cytologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• senioři MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

• Klíčová slova
• ACETYLCHOLINE *, MUSCLE RELAXANTS *, MYONEURAL JUNCTION *, NEUROLOGY *, NICOTINE *,
• MeSH
• acetylcholin * MeSH
• centrálně působící myorelaxancia * MeSH
• lidé MeSH
• nervosvalové spojení * MeSH
• neurologie * MeSH
• nikotin * MeSH
• svaly * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• acetylcholin * MeSH
• centrálně působící myorelaxancia * MeSH
• nikotin * MeSH

Spasticity often results in significant disability, which complicates rehabilitation and daily activities. This review explores the role of botulinum toxin type A (BoNT-A) in the treatment of spasticity, focusing on its effects on muscle structure and activity, function, cortical reorganization, and pain. Our findings indicate that BoNT-A injections improve motor function and gait, particularly in stroke patients, by reducing abnormal muscle activity and enhancing postural control. However, BoNT-A may also induce unwanted biomechanical changes, such as muscle atrophy and alterations in contractile elements, which could impact long-term muscle function. Regarding pain management in spasticity, BoNT-A has shown promise by reducing both peripheral and central sensitization mechanisms. Additionally, BoNT-A influences the central nervous system (CNS) by inducing cortical reorganization, which may further contribute to clinical improvements. Lastly, BoNT-A treatment requires careful consideration of individual patient characteristics to optimize outcomes and minimize side effects. A multidisciplinary approach that combines BoNT-A with physical therapy is essential to maximize functional recovery and improve the quality of life in patients with spasticity.

• Klíčová slova
• Botulinum toxin, Cortical reorganization, Muscle, Pain, Spasticity,
• MeSH
• bolest * farmakoterapie   MeSH
• botulotoxiny typu A * terapeutické užití   farmakologie   MeSH
• kosterní svaly * účinky léků   MeSH
• lidé MeSH
• management bolesti MeSH
• nervosvalové látky * terapeutické užití   farmakologie   MeSH
• svalová spasticita * farmakoterapie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• botulotoxiny typu A * MeSH
• nervosvalové látky * MeSH

There is increasing pressure on meat producers worldwide due to the need for higher yields and improved meat quality. This is why anabolic androgenic steroids (AAS) have been widely used in most countries, due to their ability to accelerate animal muscle growth. However, out of concern for their side effects, EU states have banned their use and implemented control mechanisms. But they are reaching their limits, and therefore, it is necessary to look for new ways and investigate the mechanism of action of AAS on muscle tissue. This study replicated the administration of banned AAS (testosterone, nandrolone and their combination) and observed their effect on pig muscle. The pig model was purposely chosen for the study, as no such research has been carried out on this species. At the same time, pork is one of the most consumed meats in Europe. It focused on histological changes in muscle structure, specifically the size of muscle fibres and the number of satellite cells per muscle fibre. Furthermore, ultrastructural changes in muscle fibres, the diameter of myofibrils, the number of myofibrils per area, the distance between myofibrils and the size of sarcomeres were examined. The results using the techniques of histology, fluorescent labelling and transmission electron microscopy showed that, after the application of AAS, there is an increase in the diameter of muscle fibres, an increase in the diameter of myofibrils, a decrease in the number of myofibrils per surface area and, in the case of testosterone, an increase in the distance between myofibrils and an increase in the length of sarcomeres. There was also a significant increase in the number of satellite cells per muscle fibre. The detected statistically significant differences between control and experimental groups provide evidence that selected histological parameters could be additional mechanisms for detecting the presence of AAS in pork meat in the future.

• Klíčová slova
• anabolic steroids, electron microscopy, histology, muscles, pigs,
• MeSH
• anabolika * farmakologie   MeSH
• androgeny farmakologie   MeSH
• kosterní svalová vlákna * účinky léků   ultrastruktura   MeSH
• kosterní svaly účinky léků   ultrastruktura   MeSH
• myofibrily * účinky léků   ultrastruktura   MeSH
• nandrolon * farmakologie   aplikace a dávkování   MeSH
• prasata MeSH
• satelitní buňky kosterního svalu účinky léků   MeSH
• testosteron * farmakologie   aplikace a dávkování   MeSH
• transmisní elektronová mikroskopie veterinární   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• anabolika * MeSH
• androgeny MeSH
• nandrolon * MeSH
• testosteron * MeSH

During the early postnatal period, the differentiation and maturation of muscle spindles in the rat is still dependent on their sensory innervation. When a nerve is crushed during this period, most spindles in the denervated muscles degenerate and after reinnervation only occasional spindles of atypical structure are to be found in these muscles. We determined the basic functional properties of these atypical spindles in adult rats and attempted to correlate them with their structural characteristics. The discharge rates of 13 afferent units from the soleus or lateral gastrocnemius muscles were evaluated in response to stretch. These units were capable of a slowly adapting response to 2-4 mm stretches. Their mean discharge frequencies at any point of the ramp-and-hold stretch were, however, on an average 50% lower than normal values. The conduction velocities of afferents from the atypical spindles were in the range of 10-40 m/s. Histological examinations revealed that 90% of the atypical muscle spindles found in the soleus or lateral gastrocnemius muscles had only 1 or 2 intrafusal fibres without any nuclear accumulations as compared to four intrafusal fibres in normal muscle spindles in the rat. The proportional decrease of the discharge rate in both the dynamic and static part of the response of these atypical spindles could be due to the decreased synaptic area between the sensory terminals and the intrafusal fibres and/or to altered structural properties of the intrafusal fibres.

• MeSH
• akční potenciály MeSH
• časové faktory MeSH
• denervace svalu * MeSH
• inbrední kmeny potkanů MeSH
• krysa rodu Rattus MeSH
• mechanoreceptory fyziologie   MeSH
• nervové vedení MeSH
• počet buněk MeSH
• rozdrcení nervu MeSH
• svaly cytologie   inervace   fyziologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

The sine oculis homeobox 1 (Six1) gene encodes an evolutionarily conserved transcription factor. In the past two decades, much research has indicated that Six1 is a powerful regulator participating in skeletal muscle development. In this review, we summarized the discovery and structural characteristics of Six1 gene, and discussed the functional roles and molecular mechanisms of Six1 in myogenesis and in the formation of skeletal muscle fibers. Finally, we proposed areas of future interest for understanding Six1 gene function.

• Klíčová slova
• Molecular mechanism., Muscle, Muscle fiber, Muscle progenitors, Regulatory network, Six1,
• MeSH
• buněčný rodokmen genetika   fyziologie   MeSH
• druhová specificita MeSH
• homeodoménové proteiny genetika   metabolismus   MeSH
• kosterní svaly růst a vývoj   metabolismus   MeSH
• regulace genové exprese fyziologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• homeodoménové proteiny MeSH

Skeletal muscle relies on mitochondria for sustainable ATP production, which may be impacted by reduced oxygen availability (hypoxia). Compared with long-term hypoxia, the mechanistic in vivo response to acute hypoxia remains elusive. Therefore, we aimed to provide an integrated description of the Musculus gastrocnemius response to acute hypoxia. Fasted male C57BL/6JOlaHsd mice, fed a 40en% fat diet for six weeks, were exposed to 12% O2 normobaric hypoxia or normoxia (20.9% O2) for six hours (n = 12 per group). Whole-body energy metabolism and the transcriptome response of the M. gastrocnemius were analyzed and confirmed by acylcarnitine determination and Q-PCR. At the whole-body level, six hours of hypoxia reduced energy expenditure, increased blood glucose and tended to decreased the respiratory exchange ratio (RER). Whole-genome transcriptome analysis revealed upregulation of forkhead box-O (FOXO) signalling, including an increased expression of tribbles pseudokinase 3 (Trib3). Trib3 positively correlated with blood glucose levels. Upregulated carnitine palmitoyltransferase 1A negatively correlated with the RER, but the significantly increased in tissue C14-1, C16-0 and C18-1 acylcarnitines supported that β-oxidation was not regulated. The hypoxia-induced FOXO activation could also be connected to altered gene expression related to fiber-type switching, extracellular matrix remodeling, muscle differentiation and neuromuscular junction denervation. Our results suggest that a six-hour exposure of obese mice to 12% O2 normobaric hypoxia impacts M. gastrocnemius via FOXO1, initiating alterations that may contribute to muscle remodeling of which denervation is novel and warrants further investigation. The findings support an early role of hypoxia in tissue alterations in hypoxia-associated conditions such as aging and obesity.

• Klíčová slova
• FOXO, Hypoxia, Metabolism, Mitochondria, Neuromuscular junction, Skeletal muscle,
• Publikační typ
• časopisecké články MeSH

• MeSH
• aorta ultrastruktura   MeSH
• arteria pulmonalis ultrastruktura   MeSH
• cytoskelet ultrastruktura   MeSH
• králíci MeSH
• svaly hladké cévní ultrastruktura   MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Granulosa cells (GCs) have many functions and are fundamental for both folliculogenesis and oogenesis, releasing hormones and communicating directly with the oocyte. Long-term in vitro cultures of GCs show significant stem-like characteristics. In the current study, RNA of human ovarian granulosa cells was collected at 1, 7, 15 and 30 days of long-term in vitro culture. Understanding the process of differentiation of GCs towards different cell lineages, as well as the molecular pathways underlying these mechanisms, is fundamental to revealing other possible stemness markers of this type of cell. Identifying new markers of GC plasticity may help to understand the aetiology and recurrence of a wide variety of diseases and health conditions and reveal possible clinical applications of the ovarian tissue cells, affecting not only the reproductive ability but also sex hormone production. Granulosa cells were the subject of this study, as they are readily available as remnant material leftover after in vitro fertilisation procedures and exhibit significant stem-like characteristics in culture. The change in gene expression was investigated through a range of molecular and bioinformatic analyses. Expression microarrays were used, allowing the identification of groups of genes typical of specific cellular pathways. This candidate gene study focused on ontological groups associated with muscle cell morphogenesis, structure, development and differentiation, namely, "muscle cell development", "muscle cell differentiation", "muscle contraction", "muscle organ development", "muscle organ morphogenesis", "muscle structure development", "muscle system process" and "muscle tissue development". The results showed that the 10 most upregulated genes were keratin 19, oxytocin receptor, connective tissue growth factor, nexilin, myosin light chain kinase, cysteine and glycine-rich protein 3, caveolin 1, actin, activating transcription factor 3 and tropomyosin, while the 10 most downregulated consisted of epiregulin, prostaglandin-endoperoxide synthase 2, transforming growth factor, interleukin, collagen, 5-hydroxytryptmine, interleukin 4, phosphodiesterase, wingless-type MMTV integration site family and SRY-box 9. Moreover, ultrastructural observations showing heterogeneity of granulosa cell population are presented in the study. At least two morphologically different subpopulations were identified: large, light coloured and small, darker cells. The expression of genes belonging to the mentioned ontological groups suggest the potential ability of GCs to differentiate and proliferate toward muscle lineage, showing possible application in muscle regeneration and the treatment of different diseases.

• Klíčová slova
• human GCs, in vitro culture, muscle differentiation, proliferation,
• Publikační typ
• časopisecké články MeSH

The phenomenon of microvibrations was described by Rohracher in Vienna in the 1950s. Microvibrations consist of oscillationns in the frequency range of 7 to 13 Hz which can be observed on the surface of the body during a complete muscle relaxation. We had the opportunity to study the changes of microvibrations and physiological tremor under the condition of weightlessness in the Russian Space Station MIR during the so called "Austromir" project and the following Russian long term flights including the record flight of cosmonaut Polyakow. The recordings have been made by accelerometers from the body surface. It was found that during wieghtlessness the typical 7 to 13 Hz oscillations disappeared as well from microvibrations as from physiological tremor. By the application of a simple model it can be shown that microvibrations are due to mechanical resonance. The oscillations are apparently elicited by the heart beat. Therefore it appears that microvibrations are cardioballistic phenomena. It can be shown that cardioballistic forces are transmitted by osseous structures to soft tissues like e.g. relaxed muscles. Local resonance finally leads to the oscillations as mentioned above. From the model calculations we conclude that the relaxation is much more pronounced during weightlessness. Thus, resonance is abolished in the frequency region mentioned above. On the ground even during muscle relaxation there is still some muscle tone with an elastic component which under this condition permits the generation of resonance phenomena. Our results permit a new interpretation of microvibrations. Furthermore, the results may have importance for the interpretation of the generation of certain pathological forms of tremor.

• MeSH
• balistokardiografie MeSH
• dospělí MeSH
• kosmický let * MeSH
• kosterní svaly fyziologie   patofyziologie   MeSH
• lidé MeSH
• relaxace svalu fyziologie   MeSH
• srdeční frekvence fyziologie   MeSH
• stav beztíže * MeSH
• svalová kontrakce fyziologie   MeSH
• svalový tonus fyziologie   MeSH
• tremor patofyziologie   MeSH
• vibrace MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH