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1.
J Fish Biol ; 91(5): 1517-1525, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28990671

RESUMO

Species-specific restriction fragment length polymorphism in the intron of the androgen receptor gene (ar5) was found in glass to silver-stage individuals of Anguilla japonica (n = 51) and A. marmorata (n = 21). The sequence analysis of 16S rDNA from 328 anguillid leptocephali collected in the North Equatorial Current of the western North Pacific Ocean revealed the specimens to be A. japonica (n = 194), A. marmorata (n = 128), A. bicolor pacifica (n = 5) and A. luzonensis (n = 1). All leptocephali of A. japonica and A. marmorata were monomorphic and did not share an allele at the ar5 locus, indicating that the two species are reproductively isolated.


Assuntos
Anguilla/fisiologia , Isolamento Reprodutivo , Anguilla/genética , Animais , DNA Ribossômico/química , Oceano Pacífico , Polimorfismo de Fragmento de Restrição , Reprodução , Análise de Sequência de DNA , Especificidade da Espécie , Simpatria
2.
J Fish Biol ; 90(3): 773-785, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27778341

RESUMO

To examine species composition and population structures in sand lance (Ammodytidae) along the northern Pacific coast of Japan, genetic analysis were carried out for specimens collected in 2014 from Otsuchi Bay, Iwate, Ishinomaki Bay, Miyagi, off Soma, Fukushima and Ise-Mikawa Bays, Aichi. The samples consisted of Ammodytes japonicus and Ammodytes heian, of which the latter is a recently described species. Neither species exhibited significant genetic differences among localities. Only A. japonicus was found in the most southern locality at Aichi, but it decreased northward to <90% in Miyagi and Fukushima and the two species occurred almost evenly in Iwate suggesting a latitudinal cline in their species composition along the northern Pacific coast of Japan, off Tohoku. The vertebral counts differed between A. japonicus and A. heian with modes of 65 and 63, respectively, but this characteristic did not differ significantly within a locality (Iwate). This suggests that the vertebral counts of Ammodytes spp. in Japanese waters are probably strongly determined by the environment than by a species-specific genetic trait.


Assuntos
Meio Ambiente , Perciformes/anatomia & histologia , Coluna Vertebral/anatomia & histologia , Animais , Interação Gene-Ambiente , Japão , Oceano Pacífico , Perciformes/genética
3.
Rev Sci Instrum ; 85(11): 11D805, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25430218

RESUMO

A new antenna array is proposed in order to improve the sensitivity and complexity of microwave imaging diagnostics systems such as a microwave imaging reflectometry, a microwave imaging interferometer, and an electron cyclotron emission imaging. The antenna array consists of five elements: a horn antenna, a waveguide-to-microstrip line transition, a mixer, a local oscillation (LO) module, and an intermediate frequency amplifier. By using an LO module, the LO optics can be removed, and the supplied LO power to each element can be equalized. We report details of the antenna array and characteristics of a prototype antenna array.

4.
J Dent Res ; 93(2): 207-11, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24300309

RESUMO

The sibilant /s/ is produced by raising the tongue against the roof of the mouth to form a narrow constriction, which is adjusted so that the airstream emerging from it impinges on the incisors. However, the location where the sibilant sound occurs is unclear, as are the details of the mechanisms of its generation. In this study, we used a realistically shaped replica produced with a three-dimensional printer and demonstrated that turbulent flow was generated in the oral tract near the incisors and lips and that sufficiently developed turbulent flow generated a sound source up to 20,000 Hz at 333, 500, and 667 cm(3)/sec, which agrees with the range of physiological flow rates typical for /s/. The characteristics of the sound spectra agreed with those of the sibilant /s/ sound emitted by our control individual. Such a physical perspective could yield knowledge useful for oral surgery and speech science - for example, to predict how the generation of sibilants may be occasionally affected by orthodontic and prosthodontic treatments.


Assuntos
Modelos Dentários , Fonética , Tomografia Computadorizada por Raios X/métodos , Adulto , Desenho Assistido por Computador , Tomografia Computadorizada de Feixe Cônico/métodos , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Incisivo/fisiologia , Lábio/fisiologia , Masculino , Palato/fisiologia , Impressão/métodos , Reologia , Espectrografia do Som , Medida da Produção da Fala , Língua/fisiologia
5.
Transl Psychiatry ; 2: e188, 2012 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-23149452

RESUMO

To better understand the cellular pathogenetic mechanisms of fetal alcohol spectrum disorder (FASD) and the therapeutic benefit of stem cell treatment, we exposed pregnant rats to ethanol followed by intravenous administration of neural stem cells (NSCs) complexed with atelocollagen to the new born rats and studied recovery of GABAergic interneuron numbers and synaptic protein density in the anterior cingulate cortex, hippocampus and amygdala. Prenatal ethanol exposure reduced both parvalbumin-positive phenotype of GABAergic interneurons and postsynaptic density protein 95 levels in these areas. Intravenous NSC treatment reversed these reductions. Furthermore, treatment with NSCs reversed impaired memory/cognitive function and social interaction behavior. These experiments underscore an important role for synaptic remodeling and GABAergic interneuron genesis in the pathophysiology and treatment of FASD and highlight the therapeutic potential for intravenous NSC administration in FASD utilizing atelocollagen.


Assuntos
Transtornos do Espectro Alcoólico Fetal/terapia , Transtornos da Memória/terapia , Células-Tronco Neurais/transplante , Reconhecimento Psicológico , Tonsila do Cerebelo/metabolismo , Tonsila do Cerebelo/fisiopatologia , Animais , Animais Recém-Nascidos , Comportamento Animal , Transtornos Cognitivos/metabolismo , Transtornos Cognitivos/fisiopatologia , Transtornos Cognitivos/terapia , Modelos Animais de Doenças , Feminino , Transtornos do Espectro Alcoólico Fetal/metabolismo , Transtornos do Espectro Alcoólico Fetal/fisiopatologia , Neurônios GABAérgicos/metabolismo , Giro do Cíngulo/metabolismo , Giro do Cíngulo/fisiopatologia , Hipocampo/metabolismo , Hipocampo/fisiopatologia , Interneurônios/metabolismo , Transtornos da Memória/metabolismo , Transtornos da Memória/fisiopatologia , Gravidez , Ratos , Ratos Wistar , Comportamento Social , Transplante de Células-Tronco
6.
Rev Sci Instrum ; 83(10): 10E305, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23126965

RESUMO

Three-dimensional (3D) microwave imaging reflectometry has been developed in the large helical device to visualize fluctuating reflection surface which is caused by the density fluctuations. The plasma is illuminated by the probe wave with four frequencies, which correspond to four radial positions. The imaging optics makes the image of cut-off surface onto the 2D (7 × 7 channels) horn antenna mixer arrays. Multi-channel receivers have been also developed using micro-strip-line technology to handle many channels at reasonable cost. This system is first applied to observe the edge harmonic oscillation (EHO), which is an MHD mode with many harmonics that appears in the edge plasma. A narrow structure along field lines is observed during EHO.

7.
Rev Sci Instrum ; 81(10): 10D915, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21033947

RESUMO

A simultaneous projection/detection system of four different frequencies for microwave imaging reflectometry (MIR) was developed for three-dimensional observation of electron density fluctuations in the Large Helical Device (LHD). The microwave with four frequency components at 60.410, 61.808, 63.008, and 64.610 GHz is projected in a continuous-wave mode to illuminate the target LHD plasma. A two-dimensional horn-antenna mixer array (2D HMA) receives the reflected wave from the plasma as well as the wave from the local oscillator operating at 55.800 GHz. The first intermediate frequency (IF) signals at 4.610, 6.008, 7.208, and 8.810 GHz were confirmed to be obtained by downconversion of these microwaves using the 2D HMA. Each of these first IF components is filtered from each other and downconverted again for the superheterodyne detection. It was confirmed that both the amplitudes and the phases of the detected signals reflect the fluctuations in LHD plasmas.

8.
Rev Sci Instrum ; 81(10): 10D916, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21033948

RESUMO

We developed and installed an electron cyclotron emission radiometer for taking measurements of Korea Superconducting Tokamak Advanced Research (KSTAR) plasma. In order to precisely measure the absolute value of electron temperatures, a calibration measurement of the whole radiometer system was performed, which confirmed that the radiometer has an acceptably linear output signal for changes in input temperature. It was also found that the output power level predicted by a theoretical calculation agrees with that obtained by the calibration measurement. We also showed that the system displays acceptable noise-temperature performance around 0.23 eV.

9.
Rev Sci Instrum ; 81(10): 10D919, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21033951

RESUMO

A combined system of microwave imaging reflectometry and electron cyclotron emission (ECE) imaging has been developed for the Large Helical Device. This system includes a wide-band two-dimensional horn-antenna mixer array (HMA). The HMA consists of horn antennas, waveguides, mixers, and intermediate frequency circuits. The frequency response of the HMA is between 50 and 110 GHz. The ECE signal is selected using a 95 GHz local oscillator and a 93 GHz high-pass filter.

10.
Diabetes Obes Metab ; 12(9): 790-7, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20649631

RESUMO

AIM: The aim of this study was to evaluate the efficacy of two group-based lifestyle interventions in ameliorating the risk factors of metabolic syndrome (MS) and insulin resistance. METHODS: Ninety-eight subjects who had at least one component of MS were randomized into standard intervention (SI) (4-month intervention; n = 50) and extended intervention (EI) (10-month intervention; n = 48) groups, and 39 subjects were followed up for a control group. The effects of intervention were evaluated after 10, 22 and 34 months. RESULTS: At month 10, the standard and EI groups showed improved body mass index (BMI) (SI, -0.28; EI, -0.47; control, -0.09), high-density lipoprotein (HDL) cholesterol, fasting plasma glucose and A1c and a decreased mean number of components of MS (SI, -0.37; EI, -0.51; control, 0.08). At month 34, the effects on BMI (SI, -0.66; EI, -0.60; control, -0.05) and HDL-cholesterol were sustained for both the intervention groups. In controls, the increases in fasting plasma glucose and the mean number of components of MS from the baseline to month 34 were greater than those in the standard and EI groups. Whole body insulin sensitivity index and hepatic insulin resistance index were also improved at month 10. CONCLUSIONS: Group-based lifestyle intervention could be an efficient way to prevent MS. Its effects were sustainable, at least in part, for 2 years. These effects may be mediated by an improvement in insulin sensitivity.


Assuntos
Resistência à Insulina/fisiologia , Metabolismo dos Lipídeos/fisiologia , Síndrome Metabólica/prevenção & controle , Comportamento de Redução do Risco , Adulto , Idoso , Feminino , Humanos , Japão/epidemiologia , Masculino , Síndrome Metabólica/epidemiologia , Síndrome Metabólica/etiologia , Pessoa de Meia-Idade , Fatores de Risco
11.
Phys Rev Lett ; 104(6): 065001, 2010 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-20366824

RESUMO

The toroidal current has been rapidly ramped-up after the formation of an initial closed flux surface in an electron cyclotron heated discharge in the low aspect ratio torus experiment device. A current carrying fast electron tail is developed well beyond the runaway velocity against the reverse voltage from self-induction, suggesting a forward driving force on the tail by the cyclotron absorption of high N(parallel) electron Bernstein waves.

12.
J Parasitol ; 95(5): 1227-32, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19413366

RESUMO

The Alaska pollock, Theragra chalcogramma (Pallas), is an important raw source for surimi and other food products in Japan. However, Alaska pollock caught in the Atlantic and Mediterranean regions has been reported to harbor Anisakis species that pose considerable food safety problems. Here, we identified the third-stage (L3) Anisakis spp. sampled from Alaska pollock caught in northern Japan using a combination of morphological and molecular analyses which included PCR-RFLP and sequencing of the ITS (ITS1-5.8S rDNA-ITS2) region and mtDNA cox2 gene markers. Four Anisakis spp. were confirmed, namely Anisakis simplex (sensu stricto [s.s.]), A. pegreffii, A. brevispiculata, and an Anisakis sp. belonging to the Anisakis Type II group. The identification of 4 different Anisakis spp. occurring in Alaska Pollock, and the identification of A. brevispiculata and an Anisakis sp. (Anisakis Type II) in the northwest Pacific region, are first reports. Anisakis simplex (s.s.) composed the majority of Anisakis spp. in Alaska pollock at 91.0%, followed by A. pegreffii (5.2%), Anisakis sp. (Anisakis Type II) (2.4%), and A. brevispiculata (1.4%).


Assuntos
Anisaquíase/veterinária , Anisakis/isolamento & purificação , Doenças dos Peixes/parasitologia , Gadiformes/parasitologia , Animais , Anisaquíase/epidemiologia , Anisaquíase/parasitologia , Anisakis/anatomia & histologia , Anisakis/classificação , Anisakis/genética , Sequência de Bases , Ciclo-Oxigenase 2/genética , DNA Mitocondrial/química , DNA Espaçador Ribossômico/química , Doenças dos Peixes/epidemiologia , Parasitologia de Alimentos , Marcadores Genéticos , Japão/epidemiologia , Larva/anatomia & histologia , Larva/classificação , Larva/genética , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase/veterinária , Polimorfismo de Fragmento de Restrição , Mapeamento por Restrição/veterinária , Alimentos Marinhos/efeitos adversos , Alimentos Marinhos/parasitologia , Alinhamento de Sequência/veterinária
13.
J Fish Biol ; 74(9): 1853-65, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20735676

RESUMO

Extensive collections were made of the larvae of the temperate Japanese eel Anguilla japonica and the tropical giant mottled eel Anguilla marmorata in an overlapping area of the North Equatorial Current region of the western North Pacific Ocean. Collections of 189 A. marmorata and > 2500 A. japonica larvae during nine surveys from 1991 to 2007 showed that these two anguillid eels have similar spawning areas just west of the southern West Mariana Ridge. In July to August 2006 and August 2007, morphologically and genetically identified A. marmorata preleptocephali were mainly collected between 14.5-15 degrees N and 142-142.5 degrees E, where A. japonica preleptocephali were also caught in some of the same net tows. Fewer A. marmorata preleptocephali, however, were collected (n = 31) compared to those of A. japonica (n = c. 165), and fewer small larvae of A. marmorata were collected per tow than A. japonica (n = 1-10 and 1-294, respectively), suggesting relatively smaller spawning aggregations of A. marmorata. The distribution of preleptocephali and small larvae was wider in longitude in A. marmorata (131- 143 degrees E) than in A. japonica (137-143 degrees E), while the latitudinal range was almost the same (12-17 degrees N). Although spawning by these two species overlaps both spatially and temporally, the tropical eels of the North Pacific population of A. marmorata probably have a much longer spawning season with fewer spawners, at least in summer, and recruit to a much wider latitudinal range of growth habitats.


Assuntos
Anguilla/fisiologia , Reprodução , Animais , Larva/fisiologia , Oceano Pacífico
14.
Rev Sci Instrum ; 79(10): 10F111, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19044595

RESUMO

Three key devices of the microwave imaging reflectometry (MIR) are under development in large helical device (LHD). The 2-D mixer array is developed by stacking the one-dimensional array of the planar Yagi-Uda antenna. The new type of the bandpass filter bank is modified to match the requirement of the MIR. The low-cost quadrature demodulator is also developed for the phase detection system. By using the low-price commercial wireless devices, the development cost becomes much lower than the expensive waveguide system. These devices enable the development of 2-D/3-D microwave imaging system for the plasma diagnostics and industrial applications.

15.
J Neural Transm Suppl ; (72): 331-7, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17982911

RESUMO

Neural stem cell (NSC) transplantation has been investigated and developed in areas such as brain injury, stroke and neurodegenerative diseases. Recently, emerging evidence suggest that many of clinical symptoms observed in psychiatric disease are likely related to neural network disruptions including neurogenesis dysfunction. In the present study, we transplanted NSCs into a model of fetal alchol effects (FAE) for the purpose of investigating the possibility of regenerative therapy for the FAE. We labeled NSCs with fluorescent dye and radioisotope which were transplanted into FAE rats by intravenous injection. The transplanted cells were detected in wide areas of brain and were greater in number in the brains of the FAE group compared to the control group. Furthermore NSC transplantation attenuated behavioral abnormalities in FAE animals. These results suggest NSC transplantation as a potental new therapy for human FAE.


Assuntos
Modelos Animais de Doenças , Células-Tronco Embrionárias/transplante , Transtornos do Espectro Alcoólico Fetal/cirurgia , Regeneração Nervosa/fisiologia , Neurônios/citologia , Animais , Animais Recém-Nascidos , Encéfalo/patologia , Diferenciação Celular/fisiologia , Movimento Celular/fisiologia , Células-Tronco Embrionárias/patologia , Comportamento Exploratório/fisiologia , Medo/fisiologia , Feminino , Transtornos do Espectro Alcoólico Fetal/patologia , Humanos , Injeções Intravenosas , Aprendizagem em Labirinto/fisiologia , Microscopia de Fluorescência , Neurônios Motores/fisiologia , Neurônios/patologia , Gravidez , Ratos , Ratos Wistar
16.
Phys Rev Lett ; 96(12): 125005, 2006 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-16605918

RESUMO

Spontaneous current jump resulting in the formation of closed field equilibrium has been observed in electron-cyclotron-heated toroidal plasmas under steady external fields composed of a toroidal field and a relatively weak vertical field in the low aspect ratio torus experiment device. This bridges the gap between the open field equilibrium maintained by a pressure-driven current in the external field and the closed field equilibrium at a larger current. Experimental results and theoretical analyses suggest a current jump model that is based on the asymmetric electron confinement along the field line appearing upon simultaneous transitions of field topology and equilibrium.

17.
Artigo em Inglês | MEDLINE | ID: mdl-16459117

RESUMO

Changes in expression of gill Na+/K+ -ATPase (NKA) on a short-term (96 h) time-course following hyposmotic shock (direct transfer to fresh water) of the euryhaline, marine milkfish were studied on gene, protein, and cell levels in this paper. Plasma osmolality and [Na+] responded with rapid declines in 3 h post-transfer yet, thereafter, remained constant. Plasma [Cl-] gradually fell to a significantly lower level at 6 h post-transfer. Gills responded to hyposmotic shock by a dual phase enhancement of NKA activity and protein abundance; (a) Before 24 h: NKA activity increased as early as 3 h and reached a maximum level from 6 to 12 h post-transfer coincided with the sustained lower levels of plasma osmolality, [Na+], and [Cl-] since 3 h post-transfer. This was followed by a gradual rise in alpha-subunit protein levels that peaked at 12 h post-transfer. Meanwhile, alpha-mRNA of NKA did no show significant change. (b) After 24 h: NKA activity as well as the amounts of alpha-subunit mRNA and protein increased significantly. Direct freshwater transfer induced a prompt and significant decrease of NKA immunoreactive (NKIR) cell abundance in filaments before 24 h, followed by a significant increase after 24 h due to their development in filaments and lamellae. Increased number of NKIR cells after 24 h of hyposmotic shock may occur in conjunction with rise of NKA activity as well as alpha-subunit mRNA and protein abundance. In conclusion, milkfish is able to avoid an excessive drop in plasma ions immediately upon hyposmotic shock and maintain plasma ions on a marginal lower level in fresh water. Notably, the initial increase in NKA activity (adjustive phase; 3-12 h) and delayed increase in NKA mRNA and protein abundance (regulatory phase; 48-96 h) indicate the importance of a higher level of the gill enzyme in milkfish upon hyposmotic shock.


Assuntos
Peixes/fisiologia , Brânquias/enzimologia , ATPase Trocadora de Sódio-Potássio/biossíntese , Animais , Água Doce , Immunoblotting , Concentração Osmolar , Pressão Osmótica , Reação em Cadeia da Polimerase , Água do Mar , Sódio/sangue
18.
Mol Genet Genomics ; 271(5): 566-76, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15069638

RESUMO

Despite recent progress in sequencing the complete genome of rice ( Oryza sativa), the proteome of this species remains poorly understood. To extend our knowledge of the rice proteome, the subcellular compartments, which include plasma membranes (PM), vacuolar membranes (VM), Golgi membranes (GM), mitochondria (MT), and chloroplasts (CP), were purified from rice seedlings and cultured suspension cells. The proteins of each of these compartments were then systematically analyzed using two-dimensional (2D) electrophoresis, mass spectrometry, and Edman sequencing, followed by database searching. In all, 58 of the 464 spots detected by 2D electrophoresis in PM, 43 of the 141 spots in VM, 46 of the 361 spots in GM, 146 in the 672 spots in MT, and 89 of the 252 spots in CP could be identified by this procedure. The characterized proteins were found to be involved in various processes, such as respiration and the citric acid cycle in MT; photosynthesis and ATP synthesis in CP; and antifungal defense and signal systems in the membranes. Edman degradation revealed that 60-98% of N-terminal sequences were blocked, and the ratios of blocked to unblocked proteins in the proteomes of the various subcellular compartments differed. The data on the proteomes of subcellular compartments in rice will be valuable for resolving questions in functional genomics as well as for genome-wide exploration of plant function.


Assuntos
Membranas Intracelulares/química , Organelas/química , Oryza/química , Proteínas de Plantas/análise , Proteoma/análise , Membrana Celular/química , Cloroplastos/química , Eletroforese em Gel Bidimensional , Complexo de Golgi/química , Espectrometria de Massas , Mitocôndrias/química
19.
Arch Environ Contam Toxicol ; 45(2): 149-58, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-14565571

RESUMO

Perfluorooctane sulfonate (PFOS) is a class of specialty chemicals used in a variety of applications, and has been found to be globally distributed in many living organisms including humans. Several analytical methods have been developed for determination of PFOS in environmental samples and biological matrices. However, these methods employ liquid chromatography/tandem mass spectrometry (LC/MS/MS), an instrumentation which has limited accessibility because it is expensive to use and maintain. In the present study we present the development of a robust analytical method using liquid chromatography/mass spectrometry (LC/MS) in combination with solid phase extraction. The high yield and concentration of the present method enabled us to quantify PFOS as low as 0.1 ng/L. This method was applied to the determination of PFOS in 142 surface water samples collected from various geographic locations around Japan. The geometric mean (geometric standard deviation) (ng/L) for river samples (n = 126) was 2.37 (4.13), with a median of 1.68 and a range of 0.3-157 ng/L, and for coastal sea water samples (n = 16) was 1.52 (4.14), with a median of 1.21 and a range of 0.2-25.2 ng/L. However, the concentrations in most of the samples were much lower than the values reported in the US, except for those from the Jinzu (135.0 ng/L) and Tama (157 ng/L) Rivers. Because surface waters in the Ara (13.0-38.5 ng/L), Tama (0.7-157.0 ng/L), and Yodo (0.9-27.3 ng/L) Rivers, sources of drinking water for more than eight million people, were moderately contaminated with PFOS, more work is needed to assess exposure to PFOS.


Assuntos
Ácidos Alcanossulfônicos/análise , Monitoramento Ambiental/métodos , Fluorocarbonos/análise , Poluentes Químicos da Água/análise , Cromatografia Líquida , Japão , Espectrometria de Massas
20.
Adv Space Res ; 30(4): 777-81, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12530363

RESUMO

The effects of gravitational unloading with or without intact neural activity and/or tension development on myosin heavy chain (MHC) composition, cross-sectional area (CSA), number of myonuclei, and myonuclear domain (cytoplasmic volume per myonucleus ratio) in single fibers of both slow and fast muscles of rat hindlimbs are reviewed briefly. The atrophic response to unloading is generally graded as follows: slow extensors > fast extensors > fast flexors. Reduction of CSA is usually greater in the most predominant fiber type of that muscle. The percentage of fibers expressing fast MHC isoforms increases in unloaded slow but not fast muscles. Myonuclear number per mm of fiber length and myonuclear domain is decreased in the fibers of the unloaded predominantly slow soleus muscle, but not in the predominantly fast plantaris. Decreases in myonuclear number and domain, however, are observed in plantaris fibers when tenotomy, denervation, or both are combined with hindlimb unloading. All of these results are consistent with the view that a major factor for fiber atrophy is an inhibition or reduction of loading of the hindlimbs. These data also indicate that predominantly slow muscles are more responsive to unloading than predominantly fast muscles.


Assuntos
Fibras Musculares de Contração Rápida/patologia , Fibras Musculares de Contração Lenta/patologia , Atrofia Muscular/fisiopatologia , Cadeias Pesadas de Miosina/biossíntese , Simulação de Ausência de Peso , Animais , Eletromiografia , Elevação dos Membros Posteriores , Fibras Musculares de Contração Rápida/enzimologia , Fibras Musculares de Contração Rápida/metabolismo , Fibras Musculares de Contração Lenta/enzimologia , Fibras Musculares de Contração Lenta/metabolismo , Músculo Esquelético/enzimologia , Músculo Esquelético/metabolismo , Músculo Esquelético/fisiopatologia , Atrofia Muscular/enzimologia , Atrofia Muscular/metabolismo , Fenótipo , Ratos , Voo Espacial , Succinato Desidrogenase/metabolismo , Ausência de Peso
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