The relationship between intramembranous particles and aquaporin molecules in the plasma membranes of normal rat skeletal muscles: a fracture-label study

2006 ◽  
Vol 55 (2) ◽  
pp. 63-68 ◽  
Author(s):  
S. Shibuya
Keyword(s):  
Skeletal Muscles ◽  
Plasma Membranes ◽  
Label Study ◽  
Intramembranous Particles ◽  
Normal Rat ◽  
The Relationship

Exercise increases the plasma membrane content of the Na+ -K+ pump and its mRNA in rat skeletal muscles

1996 ◽  
Vol 80 (2) ◽  
pp. 699-705 ◽  
Author(s):  
T. Tsakiridis ◽  
P. P. Wong ◽  
Z. Liu ◽  
C. D. Rodgers ◽  
M. Vranic ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Plasma Membrane ◽  
Skeletal Muscles ◽  
Plasma Membranes ◽  
Acute Exercise ◽  
Treadmill Running ◽  
Type I ◽  
Mrna Levels ◽  
Subunit Mrna ◽  
White Type

Muscle fibers adapt to ionic challenges of exercise by increasing the plasma membrane Na+-K+ pump activity. Chronic exercise training has been shown to increase the total amount of Na+-K+ pumps present in skeletal muscle. However, the mechanism of adaptation of the Na+-K+ pump to an acute bout of exercise has not been determined, and it is not known whether it involves alterations in the content of plasma membrane pump subunits. Here we examine the effect of 1 h of treadmill running (20 m/min, 10% grade) on the subcellular distribution and expression of Na+-K+ pump subunits in rat skeletal muscles. Red type I and IIa (red-I/IIa) and white type IIa and IIb (white-IIa/IIb) hindlimb muscles from resting and exercised female Sprague-Dawley rats were removed for subcellular fractionation. By homogenization and gradient centrifugation, crude membranes and purified plasma membranes were isolated and subjected to gel electrophoresis and immunoblotting by using pump subunit-specific antibodies. Furthermore, mRNA was isolated from specific red type I (red-I) and white type IIb (white-IIb) muscles and subjected to Northern blotting by using subunit-specific probes. In both red-I/IIa and white-IIa/IIb muscles, exercise significantly raised the plasma membrane content of the alpha1-subunit of the pump by 64 +/- 24 and 55 +/- 22%, respectively (P < 0.05), and elevated the alpha2-polypeptide by 43 +/- 22 and 94 +/- 39%, respectively (P < 0.05). No significant effect of exercise could be detected on the amount of these subunits in an internal membrane fraction or in total membranes. In addition, exercise significantly increased the alpha1-subunit mRNA in red-I muscle (by 50 +/- 7%; P < 0.05) and the beta2-subunit mRNA in white-IIb muscles (by 64 +/- 19%; P < 0.01), but the alpha2- and beta1-mRNA levels were unaffected in this time period. We conclude that increased presence of alpha1- and alpha2-polypeptides at the plasma membrane and subsequent elevation of the alpha1- and beta2-subunit mRNAs may be mechanisms by which acute exercise regulates the Na+-K+ pump of skeletal muscle.

The relationship between slow and fast myosin heavy chain content, calpastatin and meat tenderness in different ovine skeletal muscles

Meat Science ◽  
2005 ◽  
Vol 69 (1) ◽  
pp. 17-25 ◽  
Author(s):  
A.Q. Sazili ◽  
T. Parr ◽  
P.L. Sensky ◽  
S.W. Jones ◽  
R.G. Bardsley ◽  
...  
Keyword(s):  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Skeletal Muscles ◽  
Meat Tenderness ◽  
Fast Myosin ◽  
Fast Myosin Heavy Chain ◽  
The Relationship

Abundance and subcellular distribution of MCT1 and MCT4 in heart and fast-twitch skeletal muscles

2000 ◽  
Vol 278 (6) ◽  
pp. E1067-E1077 ◽  
Author(s):  
Arend Bonen ◽  
Dragana Miskovic ◽  
Mio Tonouchi ◽  
Kathleen Lemieux ◽  
Marieangela C. Wilson ◽  
...  
Keyword(s):  
Subcellular Distribution ◽  
Tibialis Anterior ◽  
Skeletal Muscles ◽  
Inverse Relationship ◽  
Extensor Digitorum Longus ◽  
Plasma Membranes ◽  
Rat Hearts ◽  
T Tubules ◽  
Fast Twitch ◽  
White Gastrocnemius

The expression of two monocarboxylate transporters (MCTs) was examined in muscle and heart. MCT1 and MCT4 proteins are coexpressed in rat skeletal muscles, but only MCT1 is expressed in rat hearts. Among six rat fast-twitch muscles (red and white gastrocnemius, plantaris, extensor digitorum longus, red and white tibialis anterior) there was an inverse relationship between MCT1 and MCT4 ( r = −0.94). MCT1 protein was correlated with MCT1 mRNA ( r = 0.94). There was no relationship between MCT4 mRNA and MCT4 protein. MCT1 ( r = −0.97) and MCT4 ( r = 0.88) protein contents were correlated with percent fast-twitch glycolytic fiber. When normalized for their mRNAs, MCT1 but not MCT4 was still correlated with the percent fast-twitch glycolytic fiber composition of rat muscles ( r = −0.98). MCT1 and MCT4 were also measured in plasma membranes (PM), triads (TR), T tubules (TT), sarcoplasmic reticulum (SR), and intracellular membranes (IM). There was an intracellular pool of MCT4 but not of MCT1. The MCT1 subcellular distribution was as follows: PM (100%) > TR (31.6%) > SR (15%) = TT (14%) > IM (1.7%). The MCT4 subcellular distribution was considerably different [PM (100%) > TR (66.5%) > TT (36%) = SR (43%) > IM (24%)]. These studies have shown that 1) the mechanisms regulating the expression of MCT1 (transcriptional and posttranscriptional) and MCT4 (posttranscriptional) are different and 2) differences in MCT1 and MCT4 expression among muscles, as well as in their subcellular locations, suggest that they may have different roles in muscle.

Comparative Study of Glycolipid Compositions of Plasma Membranes among Two Types of Rat Ascites Hepatoma and Normal Rat Liver

1978 ◽  
Vol 83 (5) ◽  
pp. 1517-1520 ◽  
Author(s):  
Takao TAKI ◽  
Yoshio HIRABAYASHI ◽  
Yoshiko SUZUKI ◽  
Makoto MATSUMOTO ◽  
Kiyohide KOJIMA
Keyword(s):  
Comparative Study ◽  
Rat Liver ◽  
Plasma Membranes ◽  
Ascites Hepatoma ◽  
Normal Rat ◽  
Rat Ascites Hepatoma

scholarly journals Substructure of the glomerular slit diaphragm in freeze-fractured normal rat kidney

1975 ◽  
Vol 65 (1) ◽  
pp. 233-236 ◽  
Author(s):  
MJ Karnovsky ◽  
GB Ryan
Keyword(s):  
Plasma Proteins ◽  
Plasma Membranes ◽  
Rat Kidney ◽  
Slit Diaphragm ◽  
Renal Glomerulus ◽  
Regular Array ◽  
Filtration Barrier ◽  
Normal Rat ◽  
Cross Bridges

In the renal glomerulus, the narrow slits between adjacent epithelial podocytes are bridged by a diaphragm (2, 8, 11). In rat and mouse kidneys fixed by perfusion with tannic acid and glutaraldehyde (TAG), it has recently been discovered that this diaphragm has a highly ordered, isoporous substructure (9). It consists of a regular array of alternating cross bridges extending from the podocyte plasma membranes to a centrally running filament. This zipperlike pattern results in two rows of rectangular pores, approximately 40 X 140 A in cross section, dimensions consistent with the proposed role of the diaphragm as an important filtration barrier to plasma proteins (6). In the present study, we found in freeze-cleaved and in freeze-etched normal rat glomeruli that the surface of the slit diaphragm has an appearance conforming to the pattern found in sectioned material.

scholarly journals Reversible particle movements associated with unstacking and restacking of chloroplast membranes in vitro.

1976 ◽  
Vol 71 (1) ◽  
pp. 136-158 ◽  
Author(s):  
L A Staehelin
Keyword(s):  
Plasma Membranes ◽  
Structural Changes ◽  
Freeze Fracture ◽  
Chloroplast Membranes ◽  
Ps Ii ◽  
Membrane Particles ◽  
Intramembranous Particles ◽  
Membrane Surfaces ◽  
Ps Ii Activity

Freeze-fracture and freeze-etch techniques have been employed to study the supramolecular structure of isolated spinach chloroplast membranes and to monitor structural changes associated with in vitro unstacking and restacking of these membranes. High-resolution particle size histograms prepared from the four fracture faces of normal chloroplast membranes reveal the presence of four distinct categories of intramembranous particles that are nonrandomly distributed between grana and stroma membranes. The large surface particles show a one to one relationship with the EF-face particles. Since the distribution of these particles between grana and stroma membranes coincides with the distribution of photosystem II (PS II) activity, it is argued that they could be structural equivalents of PS II complexes. An interpretative model depicting the structural relationship between all categories of particles is presented. Experimental unstacking of chloroplast membranes in low-salt medium for at least 45 min leads to a reorganization of the lamellae and to a concomitant intermixing of the different categories of membrane particles by means of translational movements in the plane of the membrane. In vitro restacking of such experimentally unstacked chloroplast membranes can be achieved by adding 2-20 mM MgCl2 or 100-200 mM NaCl to the membrane suspension. Membranes allowed to restack for at least 1 h at room temperature demonstrate a resegregation of the EF-face particles into the newly formed stacked membrane regions to yield a pattern and a size distribution nearly indistinguishable from the normally stacked controls. Restacking occurs in two steps: a rapid adhesion of adjoining stromal membrane surfaces with little particle movement, and a slower diffusion of additional large intramembranous particles into the stacked regions where they become trapped. Chlorophyll a:chlorophyll b ratios of membrane fraction obtained from normal, unstacked, and restacked membranes show that the particle movements are paralleled by movements of pigment molecules. The directed and reversible movements of membrane particles in isolated chloroplasts are compared with those reported for particles of plasma membranes.

Coordination Control of Arm Using Antagonistic Actuators

2002 ◽  
Vol 14 (3) ◽  
pp. 270-277 ◽  
Author(s):  
Toru Oshima ◽  
◽  
Tomohiko Fujikawa ◽  
Minayori Kumamoto ◽  
◽  
...  
Keyword(s):  
Force Control ◽  
Skeletal Muscles ◽  
Control Mode ◽  
Coordination Control ◽  
Mechanical Joint ◽  
Output Force ◽  
Link Model ◽  
The Difference ◽  
The Relationship ◽  
Antagonistic Muscles

In a mechanical joint drive used in robot arms, 1 actuator drives each joint. To drive joints in musculoskeletal animal limbs, in which skeletal muscles are used as actuators, a pair of bi-articular muscles drives 2 joints simultaneously in addition to a pair of monoarticular muscles for driving 1 joint. In our study, the mutual coordination of antagonistic mono-articular and antagonistic bi-articular muscles in in the horizontal arm plane were examined using electromyogram, results were analyzed by a mechanical 2-joint link model, and the relationship between the pattern of coordination of antagonistic muscles and output force generated by the arm clarified. A neural network model that generates the pattern of coordination was proposed to clarify the difference between conventional robots and animals in the force control mode for limbs.

Molecular analysis of the tight junction

1989 ◽  
Vol 47 ◽  
pp. 810-811
Author(s):  
Bruce R. Stevenson ◽  
Matthew B. Heintzelman ◽  
James Melvin Anderson ◽  
Sandra Citi ◽  
I. Deborah Braun ◽  
...  
Keyword(s):  
Tight Junction ◽  
Plasma Membranes ◽  
Cell Structure ◽  
Ultrastructural Localization ◽  
Physical Analysis ◽  
Biochemical Level ◽  
Membrane Contact ◽  
Relationship Of ◽  
Junction Structure ◽  
The Relationship

The tight junction (zonula occludens) constitutes a selectively permeable barrier in the paracellular pathway of most epithelia. It is also thought to play a role in the maintenance of the cell surface compositional asymmetry characteristic of epithelial cells. The identification of ZO-1 and cingulin, the first two proteins found to be exclusively associated with the tight junction, permits novel investigations of this important epithelial cell structure at the biochemical level.ZO-1 is a high molecular weight polypeptide (>200 kD) found at the tight junctions of a variety of epithelia as well as endothelia, and ultrastructural localization studies on isolated liver plasma membranes indicate that this molecule is clustered at the points of membrane contact on the cytoplasmic surface of the junction. Physical analysis demonstrates ZO-1 to be an elongated, monomeric, phosphorylated protein, peripherally associated with the junctional membrane. Cingulin was originally isolated from chicken intestine, and, like ZO-1, is a peripheral membrane component of the junction which exhibits an elongated shape. Antibodies directed against this molecule show two primary bands at 140 kD and 108 kD on immunoblots of several epithelial tissues, although the relationship between these two elements remains undefined. Little information currently exists regarding the relationship of ZO-1 and cingulin to each other or to tight junction structure or function. We report here a comparison of the immunocytochemical properties of these junctional components as well as an examination of the phosphorylation state of ZO-1.

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