Morfologia e crescimento do músculo estriado esquelético no pirarucu Arapaima gigas Cuvier, 1817 (Teleostei, Arapaimidae)

The aim of this work was to evaluate the morphological, growth characteristics of skeletal muscle tissue III Pirarucu (Arapaima gigas) using alevins (50 days old) and juveniles (1 year old). Muscle samples were collected from dorsal, lateral cranial mid lateral caudal regions, and then frozen in liquid nitrogen. Histological frozen sections (10 [mu]m) were stained with HE and Gomori Trichrome for morphological analysis, and NADH-TR to evaluate muscle fiber oxidative metabolism. Morphometric analysis samples were obtained from dorsal and lateral cranial regions, and the smallest-diameter white fibers were measured. White dorsal muscle was thicker, and two muscle fiber compartments were identified in the lateral cranial region: red (superficial) mid white (deep) muscle. Hyperplasia muscle growth predominated in alevins mid hypertrophy in juveniles.

Características histoquímicas e estruturais do testículo do morcego hematófago (Desmodus rotundus rotundus, Geoffrey, 1810).

The testicular stroma of the vampire bat including the testicular capsula and the lamina propria of the seminiferous tubuli, was strongly PAS-positive. This observation was a possible indication of great amounts of structural glycogen and other glycoconjugates at the level of smooth muscle cells; elongated contractile cells and/or collagen frameworks of the tunica albuginea and tubular lamina propria. In the last the basement membranes of the seminiferous tubules were particularly strongly PAS positive, as an indication of their neutral mucosubstances structural composition, previously described (Malmi et al., 1987). The epithelium lining from the cavitary and surface rete testis complex showed low reactivities to mucosubstances; total proteins and lipids and oxidative enzymes studied. Although the apical granulation at the rete testis epithelium showed an intense PAS reactivity with hypothesis of glycoprotein secretion, through the rete. The PAS, Sudan Black B, NADH, MDH and LDH reactions of the testicular interstitium seem correlate to steroid metabolism (biosynthesis and secretion), at the Leydig cells level. The seminiferous epithelium generally had low reactions to all the histochemical studies realized. Particularly in the adbasal compartment the histochemical localizations of NADH diaphorase and LDH were possible related to glycolytic activities and general carbohydrates metabolism, both enzymes, and hydrogen transport, the NADH. The strong PAS, diastase and PAS, and alcian blue pH 2.5 and PAS reactions observed in the adluminal seminiferous epithelium compartment were directly related to the spermatids acrosomal glycoconjugates structuration. Also the SDH localization at this level seems to be related to the mitochondrial activities at the middle piece level in the late spermatids.

Histoenzymological and ultrastructural changes in lateral muscle fibers of Oreochromis niloticus (Teleostei: Cichlidae) after local injection of veratrine

The effects of veratrine have been investigated in mammalian, amphibian, and crustacean muscle, but not in fish. In this work, the action of veratrine was studied in the lateral muscle of the freshwater teleost Oreochromis niloticus after intramuscular injection. Histoenzymological typing and electron microscopy of muscle fibers before and 15, 30, and 60 min after veratrine injection (10 ng/kg fish) were used to indirectly assess the morphological changes and the oxidative and m-ATPase activities. In some cases, muscles were pretreated with tetrodotoxin to determine whether the ultrastructural changes were the result of Na+ channel activation by veratrine. Veratrine altered the metabolism of fibers mainly after 30 min. Oxidative fibers showed decreased NADH-TR activity, whereas that of glycolytic and oxidative-glycolytic type fibers increased. There was no change in the m-ATPase activity of the three fiber types, except at 60 min postveratrine, when a novel fiber type, which showed no reversal after acidic and alkaline preincubations, appeared. Ultrastructural damage involved sarcomeres, myofibrils, and mitochondria, but the T-tubules remained intact. Pretreatment with tetrodotoxin (1 ng/ml) prevented the ultrastructural changes caused by veratrine. These results show that in fish skeletal muscle veratrine produces some effects that are not seen in mammalian muscle.

Histoenzymology and morphometry of the masticatory muscles of tufted capuchin monkey (Cebus apella Linnaeus, 1758)

Samples of the anterior and posterior regions of the masseter and temporal muscles and of the anterior belly of the digastric muscle of 4 adult male tufted capuchin monkeys (Cebus apella) were removed and stained with HE and submitted to the m-ATPase reaction (with alkaline and acid preincubation) and to the NADH-TR and SDH reactions. The results of the histoenzymologic reactions were similar, except for acid reversal which did not occur in fibers of the fast glycolytic (FG) type in the mandibular locomotor muscles. FG fibers had a larger area and were more frequent in all regions studied. No significant differences in frequency or area of each fiber type were detected, considering the anterior and posterior regions of the masseter and temporal muscles. The frequency of fibers of the fast oxidative glycolytic (FOG) and slow oxidative (SO) types and of FOG area differed significantly between the anterior belly of the digastric muscle and the mandibular locomotor muscle. The predominance of fast twitch (FG and FOG) fibers and the multipenniform and bipenniform internal architecture of the masseter and temporal muscles, respectively, are characteristics that permit the powerful bite typical of tufted capuchin monkeys.

Morphometry and histochemistry of the Rectus abdominis muscle fibers of tufted capuchin monkeys (Cebus apella Linnaeus, 1758)

The phylogenetic proximity of primates to humans, along with their behavioral, biochemical, and anatomical similarities, make such animals more interesting experimental models for biomedical researches, as compared to classical laboratory animals. Another aspect that has called the attention of researchers is the differentiated quadrupedalism present in some primates. The tufted capuchin monkey uses the ground and tree branches as its support for locomotion, showing various postures while performing this task. On the basis of this information, we have decided to study the rectus abdominis muscle of the tufted capuchin monkey, with the following goals: the frequency and area of fiber types; its possible compartmentalization; and identify if this muscle is better adapted to phasic or postural activities. To do this, samples were removed from 4 regions of the rectus abdominis muscle of 6 adult male tufted capuchin monkeys, and were submitted to reaction with m-ATPase, (with alkaline and acid pre-incubation), NADH, and H.E.. Results showed: a statistically significant difference (P<0.05) for both frequency and area, between fiber types FG and FOG and FG and SO, but did not show a statistically significant difference between fibers FOG and SO, in all studied regions; similarity in frequency and area of a same fiber type (FG, FOG, and SO) among the studied regions. Based on these data, it was concluded that: the rectus abdominis muscle of the tufted capuchin monkey does not show fiber compartmentalization, since the distribution and size patterns of the different fiber types are similar in the studied regions; there is a predominance of fast twitch fibers (FG + FOG) over slow twitch fibers (SO), for frequency and area, which characterizes the muscle as being more dedicated to phasic than to postural activities. © 2006 Sociedad Chilena de Anatom.

Morphological and histochemical analysis of the human vestibular fold

A morphological and histochemical study of the human vestibular fold was carried out using routine histological techniques. Seven μm-thick histological sections stained with hematoxylin-eosin (HE) and Calleja showed the presence of elastic collagen fibers and seromucous glands in the vestibular fold. Muscle fibers forming the ventricular muscle were also identified. Ultrastructural analyses of the epithelial layer by scanning electron microscopy (SEM) revealed ciliated cells and gland ducts opening on the epithelial surface. Histochemical analyses were performed on ventricular muscles submitted to nicotinamide-adenine-dinucleotide tetrazolium reductase (NADH-TR), succinate dehydrogenase (SDH), and myofibrillar adenosine triphosphatase (mATPase) reactions. Based on these reactions, it was observed that the muscle is formed by three types of muscle fibers: slow-twitch oxidative (SO), fast-twitch oxydative glycolytic (FOG) and fast-twitch glycolytic (FG) fibers distributed in a mosaic pattern. The fiber frequency was 22.7%, 69.9% and 7.4%, respectively. The higher frequency of SO and FOG fibers characterized the muscle as having aerobic metabolism and resistance to fatigue. The ventricular muscle was considered fast. The study of the neuromuscular junctions performed after nonspecific esterase reaction showed that they are of the en-plaque type and have multiple occurrences in the ventricular muscle.

The Mycobacterium tuberculosis Rv2540c DNA sequence encodes a bifunctional chorismate synthase

Background. The emergence of multi- and extensively-drug resistant Mycobacterium tuberculosis strains has created an urgent need for new agents to treat tuberculosis (TB). The enzymes of shikimate pathway are attractive targets to the development of antitubercular agents because it is essential for M. tuberculosis and is absent from humans. Chorismate synthase (CS) is the seventh enzyme of this route and catalyzes the NADH- and FMN-dependent synthesis of chorismate, a precursor of aromatic amino acids, naphthoquinones, menaquinones, and mycobactins. Although the M. tuberculosis Rv2540c (aroF) sequence has been annotated to encode a chorismate synthase, there has been no report on its correct assignment and functional characterization of its protein product. Results. In the present work, we describe DNA amplification of aroF-encoded CS from M. tuberculosis (MtCS), molecular cloning, protein expression, and purification to homogeneity. N-terminal amino acid sequencing, mass spectrometry and gel filtration chromatography were employed to determine identity, subunit molecular weight and oligomeric state in solution of homogeneous recombinant MtCS. The bifunctionality of MtCS was determined by measurements of both chorismate synthase and NADH:FMN oxidoreductase activities. The flavin reductase activity was characterized, showing the existence of a complex between FMN ox and MtCS. FMNox and NADH equilibrium binding was measured. Primary deuterium, solvent and multiple kinetic isotope effects are described and suggest distinct steps for hydride and proton transfers, with the former being more rate-limiting. Conclusion. This is the first report showing that a bacterial CS is bifunctional. Primary deuterium kinetic isotope effects show that C4-proS hydrogen is being transferred during the reduction of FMNox by NADH and that hydride transfer contributes significantly to the rate-limiting step of FMN reduction reaction. Solvent kinetic isotope effects and proton inventory results indicate that proton transfer from solvent partially limits the rate of FMN reduction and that a single proton transfer gives rise to the observed solvent isotope effect. Multiple isotope effects suggest a stepwise mechanism for the reduction of FMNox. The results on enzyme kinetics described here provide evidence for the mode of action of MtCS and should thus pave the way for the rational design of antitubercular agents. © 2008 Ely et al; licensee BioMed Central Ltd.

Estudo morfológico e modulações dos tipos de fibras do m. reto femoral de ratos wistar, após a estimulação com corrente russa

Pós-graduação em Ciências da Motricidade - IBRC

Produção de glicerol quinase em Pichia pastoris

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Dosagem de etanol utilizando alcool desidrogenase de levedura de panificação

Pós-graduação em Alimentos e Nutrição - FCFAR

Inoculação de células-tronco mesenquimais autólogas e alogênicas, provenientes da medula óssea, em tecido muscular de equinos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estudo do músculo diafragma em ratos com insuficiência cardíaca crônica: composição das miosinas e expressão dos fatores de regulação miogênica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Desenvolvimento de metodologia high-throughput para estudo populacional do mosquito Aedes aegypti e comparação de dados de genes mitocondriais

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efeitos da abamectina na bioenergética de mitocôndrias isoladas de fígado de rato: Juliana Carla Castanha Zanoli. -

Pós-graduação em Ciência Animal - FMVA

Caracterização histológica e bioquímica dos músculos longissimus dorsi e semitendinosus de bubalinos mediterrâneo abatidos em diferentes pesos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)