Vânia Marilande Ceccatto

Vasorelaxant effects of the monoterpenic phenol isomers, carvacrol and thymol, on rat isolated aorta

Various essential oils are rich in carvacrol, a monoterpenic phenol isomeric with thymol. This study was undertaken to assess the vasorelaxant effects of thymol and carvacrol in rat isolated aorta and the putative mechanisms underlying these effects. Thymol and carvacrol produced a concentration‐dependent relaxation on the aortic ring preparations pre‐contracted using KCl (IC50 value of 64.40 ± 4.41 and 78.80 ± 11.91 μm, respectively) or using phenylephrine (PHE, 0.1 μm) (IC50 value of 106.40 ± 11.37 and 145.40 ± 6.07 μm, respectively) and inhibited the concentration‐response curves of aortic rings to PHE or KCl. In Ca2+‐free medium with ethylene glycol‐bis(2‐aminoethylether)‐N,N,N′,N′‐tetraacetic acid (2 mm), thymol and carvacrol both at 1000 μm completely abolished the phasic component of PHE‐induced endothelium‐containing ring contractions. At 400 μm, thymol and carvacrol significantly reduced the CaCl2‐induced contractions in Ca2+‐free medium. Furthermore, both thymol and carvacrol (300 and 1000 μm) significantly reduced the contraction evoked by phorbol dibutyrate (1 μm), an activator of protein kinase C. Magnitude of this inhibitory effect was enhanced in the presence of the Ca2+ pump inhibitor, thapsigargin (1 μm). At 1000 μm, neither thymol nor carvacrol altered the resting potential of vascular smooth muscle cells. In conclusion, thymol and carvacrol induced an endothelium‐independent relaxation in rat isolated aorta, an effect that seems mediated through some mechanisms probably involving a transduction pathway between Ca2+ release from sarcoplasmic reticulum and/or regulation of the Ca2+ sensitivity of the contractile system. Moreover, it’s conceivable that thymol and carvacrol, at low concentrations, block the Ca2+ influx through the membrane.

Effects of 1,8-cineole on electrophysiological parameters of neurons of the rat superior cervical ganglion.

1  1,8‐Cineole is a non‐toxic small terpenoid oxide believed to have medicinal properties in folk medicine. It has been shown to have various pharmacological effects, including blockade of the compound action potential (AP). In the present study, using intracellular recording techniques, we investigated the effects of 1,8‐cineole on the electrophysiological parameters of neurons of the superior cervical ganglion (SCG) in rats. 2  1,8‐Cineole (0.1–6 mmol/L) showed reversible and concentration‐dependent effects on various electrophysiological parameters. At 3 and 6 mmol/L, but not at 0.1 and 1 mmol/L, 1,8‐cineole significantly diminished the input resistance (Ri) and altered the resting potential (Em) to more positive values. At 6 mmol/L, 1,8‐cineole completely blocked all APs within 2.7 ± 0.6 min (n = 12). In neurons exposed to 3 and 1 mmol/L 1,8‐cineole, the effects regarding excitability varied from complete AP blockade to minor inhibition of AP parameters. The depolarization of Em and the decrease in Ri induced by 6 mmol/L 1,8‐cineole were unaltered by 200 µmol/L niflumic acid, a well known blocker of Ca2+‐activated Cl− currents. 3  Significant correlations (Pearson correlation test) were found between changes in Em and decreases in AP amplitude (r = –0.893; P < 0.00282) and maximum ascendant inclination (r = –0.799; P < 0.0173), but not for maximum descendant inclination (r = 0.598; P < 0.117). Application of current to restore the transmembrane potential equal to control Em values in the presence of 6 mmol/L 1,8‐cineole resulted in the partial recovery of AP. 4  The present study shows that 1,8‐cineole effectively blocks the excitability of SCG neurons, probably through various mechanisms, one of which acts indirectly via depolarization of the neuronal cytoplasmatic membrane.

Satellite cell activation induced by aerobic muscle adaptation in response to endurance exercise in humans and rodents.

Abstract Although the requirement of satellite cells activation and expansion following injury, mechanical load or growth stimulus provoked by resistance exercise has been well established, their function in response to aerobic exercise adaptation remains unclear. A clear relationship between satellite cell expansion in fiber‐type specific myosin heavy chain and aerobic performance has been related, independent of myonuclear accretion or muscle growth. However, the trigger for this activation process is not fully understood yet and it seems to be a multi‐faceted and well‐orchestrated process. Emerging in vitro studies suggest a role for metabolic pathways and oxygen availability for satellite cell activation, modulating the self‐renewal potential and cell fate control. The goal of this review is to describe and discuss the current knowledge about the satellite cell activation and expansion in response to aerobic exercise adaptation in human and rodent models. Additionally, findings about the in vitro metabolic control, which seems be involved in the satellite cell activation and cell fate control, are presented and discussed.

Alterações morfométricas em músculo respiratório de ratos submetidos à imobilização de pata

Immobilization is a frequently used procedure in clinical practice and common in pain diseases and fractures. This study examined the influence of immobilization in a muscle-related respiratory system, the diaphragm. This experiment was conducted with twelve male rats divided into two groups, control and immobilized with an alternative method of restraining by tape, kept for two weeks. We analyzed the morphometry of the diaphragm muscle fibers with hematoxylin/eosin staining. Statistical difference was found (p < 0.0001) when the average diameter of the diaphragm muscle fibers of immobilized animals (47.15μm ± 0.329μm) was compared to the ones in the control group (54.67μm ± 0.396μm). Considering the results, it can be concluded that the immobilization of the animal paw in the used model was able to produce hypotrophy of respiratory musculature, as well as a general framework for reducing the mass of the animal.

Antispasmodic effects of a new kaurene diterpene isolated from Croton argyrophylloides on rat airway smooth muscle.

Objectives  The effects of rel‐(1S,4aS,7S,8aS)‐7‐(1‐vinyl)‐tetradecahydro‐1,4a‐dimethylphenanthrene‐7,8a‐carbolactone‐1‐carboxylic acid (TCCA), a new ent‐kaurene diterpene isolated from Croton argyrophylloides, on rat tracheal preparations were investigated.

Sensorial, structural and functional response of rats subjected to hind limb immobilization.

AIMS This study analyzed the sensorial, structural and functional response of rats subjected to paw immobilization. MAIN METHODS Animal pelvis, hip, knee and ankle were immobilized using waterproof tape during two weeks for assessment of sensorial response to thermal (hot plate test) and mechanical stimuli (Von Frey test), motor system structure (histology and radiography) and muscle function (soleus contractility). KEY FINDINGS Disuse animals became more responsive to thermal stimuli (49%), although less responsive to mechanical challenge (58%). Disuse animals showed local injuries such as reduction in muscle fiber diameter (16.7% in gastrocnemius, 5.7% in soleus), contractile activity (55% of the control maximal tonic contraction) and tibia cortical thickness (9.3%), besides increased nitrite:protein ratio, suggestive of protein degradation. Disuse also evoked systemic adaptations that include increase in serum lactate dehydrogenase (36.1%) and alkaline phosphatase (400%), but reduction in calcium (8.4%) and total serum protein (5.5%), especially albumin (34.2%). SIGNIFICANCE Two weeks of functional paw disuse leads to local and systemic harmful adaptive changes in sensorial and structural systems. This study brings new insights into nervous and motor system mechanism associated with therapeutic limb immobilization in muscle and skeletal pathological conditions.

Anaerobic threshold employed on exercise training prescription and performance assessment for laboratory rodents: A short review.

Several studies have generated numerous terms in the field of exercise training prescription and performance assessment that often do not match the information previously demonstrated by many other works, generating much debate and resulting in an immense pool of scientific results. Several protocols in exercise training prescription and performance assessment have been proposed for these purposes by many reasons. In the field of exercise science, the protocol must be thoroughly investigated and provide real tools to be reproducible. Many laboratories have been adapting and developing evaluation protocols and testing on physical training of rodents in different experimental conditions. In this context, mice, rats and rabbits are preferentially chosen due to easy manipulation and good response to exercise, and comparable at results obtained with humans in compatible effort intensities. But, the exercise training programs and aerobic-anaerobic transition assessment proposed for animal models vary extensively, depending on the species, gender, age, type of stimulus, type of exercise, type of method and also on the specific objectives of the program. This short review demonstrates the need in offering tools performed by invasive measurement to assess the anaerobic threshold by blood lactate employed on evolution of aerobic-anaerobic parameters of rodents. The objective of this short review was to present and to discuss physical evaluation protocols applications to rodents. The table submitted may give a basis for anaerobic threshold employed on exercise training prescription and performance assessment for laboratory rodents in future research.

Abordagem Prática de Bioinformática em Evento Acadêmico-Científico na Cidade de Fortaleza-Ce

O objetivo deste estudo foi aplicar e avaliar conteudos teoricos-praticos de Bioinformatica para estudantes participantes do Curso Introducao a Bioinformatica: Da Teoria a Pratica, inserido na programacao da IX Semana da Biologia na Universidade Estadual do Ceara, no ano de 2010. A abordagem teorica consistiu de uma apresentacao de conceitos historicos, basicos e especificos dos atuais avancos das pesquisas envolvidas as areas da biologia Molecular. A pratica de “Construcao de uma Filogenia Molecular in Silico ” foi elaborada para tornar funcional os conceitos apresentados na pratica anterior, com a utilizacao do banco de dados do National Center for Biotechnology Information , NCBI, e sua ferramenta de alinhamento de sequencias, o BLASTp ( Basic Local Alignment Search Tool Protein-Protein.) Os resultados positivos obtidos com a aplicacao da aula teorica de Introducao a Bioinformatica e das atividades praticas foram destacados com as caracterizacoes das filogenias moleculares das sequencias hipoteticas propostas para a execucao dos alinhamentos e pelas falas dos alunos anteriormente citados. Estas atividades foram vistas como essenciais para que os alunos pudessem vivenciar o passo a passo para uma melhor compreensao da emergente area das ciencias da vida: a Bioinformatica.

Regulation of muscle plasticity and trophism by fatty acids: A short review

The skeletal muscle tissue has a remarkable ability to alter its plastic structural and functional properties after a harmful stimulus, regulating the expression of proteins in complex events such as muscle regeneration. In this context, considering that potential therapeutic agents have been widely studied, nutritional strategies have been investigated in order to improve the regenerative capacity of skeletal muscle. There is evidence of the modulatory action of fatty acids, such that oleic and linoleic acids, that are abundant in Western diets, on muscle function and trophism. Thus, fatty acids appear to be potential candidates to promote or impair the recovery of muscle mass and function during regeneration, since they modulate intracellular pathways that regulate myogenesis. This study is the first to describe and discuss the effect of fatty acids on muscle plasticity and trophism, with emphasis on skeletal muscle regeneration and in vitro differentiation of muscle cells.

ADAPTATION OF SKELETAL MUSCLE TO PHYSICAL EXERCISE: MOLECULAR AND ENERGY CONSIDERATIONS

The health benefits and physiological adaptations to regular physical exercise are widely known, and with the advent of the omic and molecular sciences, a complex network of signaling pathways and regulatory molecules that coordinate the adaptive response of skeletal muscle to exercise has been revealed. Transient organic changes, however, are cumulative in the post-exercise period. They mainly include transcription of genes related to regulatory factors of myogenesis, carbohydrate metabolism, fat mobilization, transport and oxidation of substrates, mitochondrial metabolism through oxidative phosphorylation, and finally, the transcriptional regulation of genes involved in mitochondrial biogenesis. Given their great scientific impact, in addition to some of the main molecular responses experienced by the skeletal muscle to exercise, factors that coordinate muscle plasticity for performance gain were summarized in this work. This review mentioned dozens of biomarkers linked to some molecular aspects of skeletal muscle adaptations to physical exercise, some major signaling pathways and the role of mitochondria, revealing some new paradigms for the understanding of this field of science.