PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Muscle, Striated”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4Linked to original sources
PubMed2005

Ultrastructural analysis of the smooth-to-striated transition zone in the developing mouse esophagus: emphasis on apoptosis of smooth and origin and differentiation of striated muscle cells.

The exact mechanism of smooth-to-striated muscle conversion in the mouse esophagus is controversial. Smooth-to-striated muscle cell transdifferentiation vs. distinct differentiation pathways for both muscle types were proposed. Main arguments for transdifferentiation were the failure to detect apoptotic smooth and the unknown origin of striated muscle cells during esophageal myogenesis. To reinvestigate this issue, we analyzed esophagi of 4-day-old mice by electron microscopy and a fine-grained sampling strategy considering that, in perinatal esophagus, the replacement of smooth by striated muscle progresses craniocaudally, while striated myogenesis advances caudocranially. We found numerous (1) apoptotic smooth muscle cells located mainly in a transition zone, where smooth intermingled with developing striated muscle cells, and (2) mesenchymal cells in the smooth muscle portion below the transition zone, which appeared to give rise to striated muscle fibers. Taken together, these results provide further evidence for distinct differentiation pathways of both muscle types during esophagus development.

Animals↗
PubMed1989

Capillary spatial pattern and muscle fiber geometry in three hamster striated muscles.

The primary goal of this project was to elucidate the spatial pattern of capillaries in three hamster striated muscles according to statistical techniques of pattern analysis. The spatial pattern of capillaries and traditional measures of capillarity are important to understanding the supply and distribution of oxygen and nutrients in a tissue. Statistical tests based on the distance between nearest neighbor capillaries are the most sensitive for detecting regularity in a pattern. A mathematical model was created to simulate the observed muscle fields. The same statistical tests that were performed on the empirical data were performed on the modelled data. The results of the analysis of the modelled data agree sufficiently with those of the empirical data to justify overall confidence in the assumptions. Conclusions that may be drawn from this investigation are (1) the spatial pattern of capillaries tends to be more regular than random and never was there evidence for aggregation using the test statistics; (2) as many as 60-75% of capillaries are located at the corners of muscle fibers indicating that there is some preferential placement for capillaries, and (3) the model developed is a good first approximation to the real situation.

Animals↗
PubMed1997

Immunocytochemical electron microscopic study and Western blot analysis of caldesmon and calponin in striated muscle of the fruit fly Drosophila melanogaster and in several muscle cell types of the earthworm Eisenia foetida.

Caldesmon and calponin are two proteins that are characteristic of vertebrate smooth muscle. In invertebrates, caldesmon has only been studied in some molluscan muscles, and no previous references to calponin have been found. The aim of this paper was to investigate the presence and distribution of caldesmon and calponin in several invertebrate muscle cell types, classified according to their ultrastructural pattern: transversely striated muscle (flight muscle from Drosophila melanogaster), obliquely striated muscle (muscular body wall and inner muscular layer of the pseudoheart from the earthworm Eisenia foetida), and a muscle of doubtful classification which seems to be intermediate between smooth muscle and obliquely striated muscle (outer muscular layer of the pseudoheart, from E. foetida), using electron microscopy immunocytochemistry and Western blot analysis. Immunoreactions to both caldesmon and calponin were observed in the outer muscular layer cells from the earthworm pseudoheart but neither in the transversely striated muscle of D. melanogaster nor in the obliquely striated muscle from the earthworm. Present findings suggest that caldesmon- and calponin-like proteins are also present in invertebrate muscle cells, but only in those that are ultrastructurally similar to the vertebrate smooth muscle cells. Since discrepancies in the classification of some invertebrate muscles are common in the literature, the use of distinctive markers, such as troponin, caldesmon and calponin may improve our understanding of the nature and properties of many invertebrate muscles showing an ultrastructural pattern that does not resemble any of the classic muscle types.

Animals↗
PubMed1972

Cytochalasin B, its interaction with actin and actomyosin from muscle (cell movement-microfilaments-rabbit striated muscle).

Cytochalasin B, an alkaloid that inhibits a wide variety of cellular movements, interacts with actomyosin, the contractile protein complex of striated muscle. This interaction causes a decrease in viscosity of the actomyosin complex and an inhibition of acto-heavy meromyosin ATPase activity of at least 60%. Cytochalasin B does not affect the viscosity of myosin nor the ATPase activity of heavy meromyosin, suggesting that the drug might interact directly with the actin moiety of the actomyosin complex. Indeed, as judged by viscometry, there is a strong interaction of cytochalasin B with actin, at nearly stoichiometric concentrations. Myosin appears to compete with cytochalasin for binding to actin.

Actins↗
PubMed1983

Muscle activity and the loss of electrical coupling between striated muscle cells in Xenopus embryos.

The gap junctions between embryonic striated muscle cells are lost during development. The time course of their elimination has been examined with electrophysiological techniques in myotomes of Xenopus laevis embryos. Gap junctions were detected by the passage of electronic current or the fluorescent dye, Lucifer Yellow, from one muscle cell to another. These tracers only spread to neighboring cells when injected intracellularly. All the muscle cells are electrically coupled at stage 24 when neuromuscular transmission begins, but normally many cells become uncoupled during the next 48 hr. In contrast, the muscle cells remain electrically coupled if neuromuscular transmission is blocked during that period with tricaine or alpha-bungarotoxin. When muscle activity recovers, the loss of coupling resumes. Once the coupling has disappeared, neuromuscular blockade does not restore it. Muscle contraction is blocked during development in a mutant of Xenopus, even though the muscle cells remain electrically excitable. After stage 32 in these immobile embryos, the muscle cells are stimulated repeatedly by regular bursts of neural activity. Although they never contract, the mutant muscle cells become uncoupled at the same time as the muscle cells in normal embryos. The results suggest that some consequence of repeated cholinergic activation, other than contraction, stimulates the loss of gap junctions between striated muscle cells during development. The elimination of gap junctions may be required for neural control of subsequent muscle differentiation.

Aminobenzoates↗
PubMed2005

Functional properties of the titin/connectin-associated proteins, the muscle-specific RING finger proteins (MURFs), in striated muscle.

The efficient functioning of striated muscle is dependent upon the proper alignment and coordinated activities of several cytoskeletal networks including myofibrils, microtubules, and intermediate filaments. However, the exact molecular mechanisms dictating their cooperation and contributions during muscle differentiation and maintenance remain unknown. Recently, the muscle specific RING finger (MURF) family members have established themselves as excellent candidates for linking myofibril components (including the giant, multi-functional protein, titin/connectin), with microtubules, intermediate filaments, and nuclear factors. MURF-1, the only family member expressed throughout development, has been implicated in several studies as an ubiquitin ligase that is upregulated in response to multiple stimuli during muscle atrophy. Cell culture studies suggest that MURF-1 specifically has a role in maintaining titin M-line integrity and yeast two-hybrid studies point toward its participation in muscle stress response pathways and gene expression. MURF-2 is developmentally down-regulated and is assembled at the M-line region of the sarcomere and with microtubules. Functionally, its expression is critical for maintenance of the sarcomeric M-line region, specific populations of stable microtubules, desmin and vimentin intermediate filaments, as well as for myoblast fusion and differentiation. A recent study also links MURF-2 to a titin kinase-based protein complex that is reportedly activated upon mechanical signaling. Finally, MURF-3 is developmentally upregulated, associates with microtubules, the sarcomeric M-line (this report) and Z-line, and is required for microtubule stability and myogenesis. Here, we focus on the biochemical and functional properties of this intriguing family of muscle proteins, and discuss how they may tie together titin-mediated myofibril signaling pathways (perhaps involving the titin kinase domain), biomechanical signaling, the muscle stress response, and gene expression.

Animals↗
PubMed1986

Ultrastructure of developing human muscle: the problem of multinucleation of striated muscle cells.

The authors studied by electron microscopy the muscle of 27 human foetuses ranging from 9 weeks to 9 months development. It was possible to observe that disintegration of the plasma membranes of adjacent myoblasts and myotubes which share a common basement membrane tube appears to occur in longitudinally disposed cells of those categories. This may help to explain how further nuclei may be incorporated into well developed myotubes and how the striated muscle cells become multinucleated during embryonic myogenesis and regeneration in vivo.

Basement Membrane↗
PubMed1998

Development of the avian iris and ciliary body: mechanisms of cellular differentiation during the smooth-to-striated muscle transition.

The avian iris and ciliary body undergoes a transition from smooth-to-striated muscle during embryonic development. Using antibodies specific for smooth muscle-specific alpha-actin and myosin heavy chain, we confirm that a smooth-to-striated muscle transition occurs between E8 and E17 in both iris and ciliary body of the chick. To study the mechanisms regulating the transition in muscle type, we analyzed the fate of quail clones derived from E7 iris cells. When cells were cloned alone, 45/71 colonies differentiated into smooth muscle and 10/71 became striated muscle. None of the colonies were mixed with respect to muscle phenotype, indicating a lack of pluripotent stem cells. Furthermore, clones giving rise to nonstriated muscle could not be forced to incorporate into myotubes when cocultured with chick myocytes. Clones grown in coculture with chick embryo fibroblasts or E11 iris cells had very high cloning efficiencies (>98%). Significantly more clones differentiated into striated muscle when cocultured with E11 cells (60/156) than when cocultured with fibroblasts (29/108). This was due to an increased recruitment of undifferentiated cells into striated muscle, rather than a change in the percentage of cells differentiating into smooth muscle. In vivo and in vitro, various smooth and striated muscle-specific markers including contractile proteins, acetylcholine receptor subtypes, and transcription factors were colocalized in cells. Although our data argue against a multipotent stem cell for smooth and striated muscle cells, they cannot exclude a role for transdifferentiation. Cumulatively these results suggest that both smooth muscle and migratory myoblasts contribute to the development of myotubes in the avian iris and that this process is regulated in a non-cell-autonomous fashion by locally generated signals.

Acetylcholine↗
PubMed1978

Mycobacterium leprae in the striated muscle of tuberculoid leprosy patients.

Striated muscle specimens from 24 untreated proved cases of tuberculoid leprosy and five healthy normal individuals were studied histopathologically for the evidence of leprous pathology. Atrophy or damage to the muscle fibre was not observed in any patient. Nineteen (79.16%) cases showed evidence of leprosy in striated muscles. Seventeen (70.83%) cases showed scanty histiocytic infiltrate between the muscle fibres. Thirteen (54.16%) cases had acid fast bacilli mostly inside the muscle. There was no correlation between the location of the bacilli and that of the histiocytes; in two cases, acid fast bacilli were seen without the histocyte. The bacilli were solidly staining and were lying singly in the undamaged muscle. There was no evidence of tuberculosis and, in the Control group, none showed any AFB or infiltrate. The presence of lepra bacilli did not depend upon the location of the muscle. Two of the muscle specimens not underneath the cutaneous lesions also had acid fast bacilli. 21.05% of these cases also showed simultaneous involvement of liver and lymph nodes. These are strong evidences of systemic nature of disease in tuberculoid leprosy as well.

Adolescent↗
PubMed1984

Striated muscle cells in the leptomeninges. An immunohistochemical study.

Striated muscle cells coexisting with neuroglial tissue were found in the leptomeninges of a 3-day-old neonate. An immunohistochemical study demonstrated the presence of myoglobin in the striated muscle cells, glial fibrillary acidic protein, and S-100 protein in the heterotopic glia, S-100 protein in the Schwann cells of the heterotopic nerve bundles, and neuron-specific enolase in some striated muscle cells as well as the neurons. A possible explanation for this may be that the striated muscle cells originated from neuroectoderm.

Aminosalicylic Acid↗
PubMed1999

Gene duplication and recruitment of a specific tropomyosin into striated muscle cells in the jellyfish Podocoryne carnea.

Cnidaria are the most basal animal phylum in which smooth and striated muscle cells have evolved. Since the ultrastructure of the mononucleated striated muscle is similar to that of higher animals, it is of interest to compare the striated muscle of Cnidaria at the molecular level to that of triploblastic phyla. We have used tropomyosins, a family of actin binding proteins to address this question. Throughout the animal kingdom, a great diversity of tropomyosin isoforms is found in non-muscle cells but only a few conserved tropomyosins are expressed in muscle cells. Muscle tropomyosins are all similar in length and share conserved termini. Two cnidarian tropomyosins have been described previously but neither of them is expressed in striated muscle cells. Here, we have characterized a new tropomyosin gene Tpm2 from the hydrozoan Podocoryne carnea. Expression analysis by RT-PCR and by whole mount in situ hybridization demonstrate that Tpm2 is exclusively expressed in striated muscle cells of the medusa. The Tpm2 protein is shorter in length than its counterparts from higher animals and differs at both amino and carboxy termini from striated muscle isoforms of higher animals. Interestingly, Tpm2 differs considerably from Tpm1 (only 19% identity) which was described previously in Podocoryne carnea. This divergence indicates a functional separation of cytoskeletal and striated muscle tropomyosins in cnidarians. These data contribute to our understanding of the evolution of the tropomyosin gene family and demonstrate the recruitment of tropomyosin into hydrozoan striated muscles during metazoan evolution. J. Exp. Zool. (Mol. Dev. Evol.) 285:378-386, 1999.

Amino Acid Sequence↗
PubMed1986

Cytochemical localization of acid phosphatase in striated muscle.

Normal skeletal and cardiac striated muscle from adult rats was incubated for the cytochemical detection of acid phosphatase activity with cerium as the capture metal. Results from these experiments show that normal striated muscle has a greater number of acid phosphatase-positive structures, which are presumed to be lysosomes, than has been indicated by several previous cytochemical studies.

Acid Phosphatase↗
PubMed1976

Some contractile and electrophysiologic properties of the periurethral striated muscle of the cat.

Evidence for differences between the periurethral striated muscle and external anal sphincter of the cat is provided by measurement of the contractile properties in situ and in vitro and the electrophysiologic properties in vitro. In the periurethral striated muscle, the contractile pressure response was faster, d-tubocurarine sensitivity was greater, d-tubocurarine blockade had a shorter duration, and fatigue was faster but not uniquely fast as compared with results for the external anal sphincter. These results suggest that the periurethral striated muscle has similar characteristics to certain fast twitch muscles. Effect of succinylcholine on the periurethral striated muscle and external anal sphincter was similar. Miniature end-plate potentials had large amplitudes which appeared to be correlated to the small diameter of the periurethral striated muscle fibers. Since only focally distributed miniature end-plate potentials could be found, true physiologically slow muscle fibers were absent.

Anal Canal↗
PubMed1996

Nonnuclear DNA binding proteins in striated muscle.

The mechanism by which striated muscle internalizes plasmid DNA is unknown. A survey of nonnuclear membrane-associated DNA binding proteins from both skeletal and cardiac muscle revealed several sarcoplasmic reticulum restricted DNA binding species. 22P-DNA overlay and DNA-cellulose chromatography were used to identify membrane-associated DNA binding proteins that may mediate the uptake and expression of plasmid DNA by striated muscle. A total membrane vesicle fraction prepared from rabbit skeletal muscle contained 95-, 60-, and 28-kDa proteins that bound double-strand DNA specifically and with high affinity. The DNA binding proteins appear to originate from the sarcoplasmic reticulum because of their absence in purified sarcolemma vesicles and codistribution with several sarcoplasmic reticulum markers after subcellular fractionation. Several distinguishing biochemical features as well as cross-reactivity with triadin-specific antibodies indicated that the 95- and 60-kDa DNA binding proteins are triadin or proteolytic fragments of triadin, respectively. The role of these sarcoplasmic reticulum proteins in the transport of plasmid DNA is discussed.

Animals↗
PubMed1979

The ultrastructure of the striated muscle of the tail of Cercaria chackai, nadakal et al., 1969.

The electron microscopic study of the tail of Cercaria chackai reveals that it contains four sets of striated muscle bundles located central to the nonstriated circular and longitudinal muscles. The striated muscle consists of longitudinally oriented lamellar myofibres. Each myofibre contains a single "U" shaped myofibril. The banding pattern is analogous to that of vertebrate striated muscle. The sarcolemma is a simple surface membrane. There are no transverse tubular extensions of sarcolemma. The sarcoplasmic reticulum (SR) is very well developed with cisternae, tubules, and vesicles. SR cisternae form dyadic couplings with the sarcolemma. There is a set of flattened tubules of SR origin traversing the myofibril exactly at the Z region. These tubules are unique to the striated muscle of the cercarian tail and may have functional significance. A diagrammatic reconstruction of the myofibre is presented.

Animals↗
PubMed1965

EFFECTS OF SODIUM AZIDE ON SODIUM FLUXES IN FROG STRIATED MUSCLE.

Unidirectional Na fluxes from frog's striated muscle were measured in the presence of 0 to 5 mM sodium azide. With azide concentrations of 2 and 5 mM the Na efflux was markedly stimulated; the Na efflux with 5 mM azide was about 300 per cent greater than normal. A similar increase was present when all but the 5.0 mM sodium added with azide was replaced by choline. 10(-5)M strophanthidin abolished the azide effect on Na(24) efflux. Concentrations of azide of 1.0 mM or less had no effect on Na efflux. The Na influx, on the other hand, was only increased by 41 per cent in the presence of 5 mM NaN(3). From these findings it is concluded that the active transport of Na is stimulated by the higher concentrations of azide. The hypothesis is advanced that the active transport of Na is controlled by the transmembrane potential and that the stimulation of Na efflux is produced as a consequence of the membrane depolarization caused by the azide.

Animals↗
PubMed2000

Intracellular Mg++ concentrations in smooth and striated muscle cells in spontaneously hypertensive rats.

Decreased intracellular Mg++ concentrations seem to be involved in the pathogenesis of primary hypertension. Of special interest is the smooth muscle cell with its electrolyte metabolism in primary hypertension, but also heart muscle cells and their Mg++ concentrations are of growing interest. Therefore, in aortic smooth muscle cells and striated heart muscle cells (left ventricle) from 20 spontaneously hypertensive rats (SHR) of the Münster strain and 20 normotensive Wistar-Kyoto rats (WKY), the intracellular Mg++ content was measured. The electron probe x-ray microanalysis technique was used to determine intracellular Mg++ concentrations under nearly in vivo conditions in aortic cryosections 3 microm thick and striated heart muscle cells 4 microm thick (Camscan CS 24 apparatus). Vascular smooth muscle Mg++ content was 36.4 +/- 3.1 mmol/kg dry weight in SHR versus 48.6 +/- 3.7 mmol/kg dry weight in WKY (P < .001). In striated heart muscle cell Mg++ concentrations, there was no significant difference in SHR and WKY (79.9 +/- 5.6 versus 80.3 +/- 5.9 mmol/ kg dry weight). In conclusion, the present study revealed that genetic hypertension in the spontaneously hypertensive rat is accompanied by significantly decreased intracellular Mg++ concentrations in vascular smooth muscle cells. In striated heart muscle cells, Mg++ content was not significantly different in SHR and WKY. Mg++ handling is different in vascular smooth muscle and striated heart muscle cells in WKY and SHR (P < .01).

Animals↗