Quantal currents and potential in the three-dimensional anisotropic bidomain model of smooth muscle

1997 ◽  
Vol 59 (6) ◽  
pp. 1047-1075 ◽  
Author(s):  
R. Henery ◽  
W. G. Gibson ◽  
M. R. Bennett
1994 ◽  
Vol 126 (2) ◽  
pp. 433-443 ◽  
Author(s):  
A McGough ◽  
M Way ◽  
D DeRosier

The three-dimensional structure of actin filaments decorated with the actin-binding domain of chick smooth muscle alpha-actinin (alpha A1-2) has been determined to 21-A resolution. The shape and location of alpha A1-2 was determined by subtracting maps of F-actin from the reconstruction of decorated filaments. alpha A1-2 resembles a bell that measures approximately 38 A at its base and extends 42 A from its base to its tip. In decorated filaments, the base of alpha A1-2 is centered about the outer face of subdomain 2 of actin and contacts subdomain 1 of two neighboring monomers along the long-pitch (two-start) helical strands. Using the atomic model of F-actin (Lorenz, M., D. Popp, and K. C. Holmes. 1993. J. Mol. Biol. 234:826-836.), we have been able to test directly the likelihood that specific actin residues, which have been previously identified by others, interact with alpha A1-2. Our results indicate that residues 86-117 and 350-375 comprise distinct binding sites for alpha-actinin on adjacent actin monomers.


Author(s):  
Marita L. Rodriguez ◽  
Sangyoon J. Han ◽  
Nathan J. Sniadecki

Vascular smooth muscle cells (VSM) modulate cardiac output, maintain vascular pressure, and regulate blood flow via contraction. This contraction is generated by a mechanochemical interaction of actin-myosin cross-bridges within each cell and is governed by the biochemical and mechanical state of the cell [1]. When this state is disturbed, VSM cells can respond with excessive constriction (which can lead to hypertension) or weakened residual stresses (which can result in aortic aneurysms); both of which are considered to be symptoms of cardiovascular diseases [2]. Furthermore, disruption in the state of VSM cells can cause their migration into the intimal layer of the artery, which is a precursor to atherosclerosis.


1966 ◽  
Vol 28 (1) ◽  
pp. 37-49 ◽  
Author(s):  
J. C. Thaemert

The muscularis externa of the intestinal wall of frogs was fixed in osmium tetroxide, embedded in Vestopal-W, serially sectioned for electron microscopy, and stained with uranyl acetate. A method to obtain individually mounted and properly positioned serial sections is described. The three-dimensional techniques used during the course of this investigation demonstrate that it is possible to examine carefully relatively large areas of tissue on individual serial sections with the electron microscope and subsequently to construct montages of electron micrographs of pertinent areas from each section. Several carefully rendered interrelationships of nerve processes and smooth muscle cells in three dimensions are exhibited and described. Recent studies of other neuro-effector relationships are discussed in relation to the present status of the nature and organization of the autonomic nervous system in visceral organs.


1994 ◽  
Vol 3 (6) ◽  
pp. 481-492 ◽  
Author(s):  
Keiichi Kanda ◽  
Takehisa Matsuda

The effect of tensile stress on the orientation and phenotype of arterial smooth muscle cells (SMCs) cultured in three-dimensional (3D) type I collagen gels was morphologically investigated. Ring-shaped hybrid tissues were prepared by thermal gelation of a cold mixed solution of type I collagen and SMCs derived from bovine aorta. The tissues were subjected to three different modes of tensile stress. They were floated (isotonic control), stretched isometrically (static stress) and periodically stretched and recoiled by 5% above and below the resting tissue length at 60 RPM frequency (dynamic stress). After incubation for up to four wk, the tissues were investigated under a light microscope (LM) and a transmission electron microscope (TEM). Hematoxylin and eosinstained LM samples revealed that, irrespective of static or dynamic stress loading, SMCs in stress-loaded tissues exhibited elongated bipolar spindle shape and were regularly oriented parallel to the direction of the strain, whereas those in isotonic control tissues were polygonal or spherical and had no preferential orientation. In Azan-stained samples, collagen fiber bundles in isotonic control tissues were somewhat retracted around the polygonal SMCs to form a random network. On the other hand, those in statically and dynamically stressed tissues were accumulated and prominently oriented parallel to the stretch direction. Ultrastructural investigation using a TEM showed that SMCs in control and statically stressed tissues were almost totally filled with synthetic organelles such as rough endoplasmic reticulums, free ribosomes, Golgi complexes and mitochondria, indicating that the cells remained in the synthetic phenotype. On the other hand, SMCs in dynamically stressed tissues had increased fractions of contractile apparatus, such as myofilaments, dense bodies and extracellular filamentous materials equivalent to basement membranes, that progressed with incubation time. These results indicate that periodic stretch, in concert with 3-D extracellular collagen matrices, play a significant role in the phenotypic modulation of SMCs from the synthetic to the contractile state, as well as cellular and biomolecular orientation.


2019 ◽  
Vol 7 (1) ◽  
pp. 347-361 ◽  
Author(s):  
Haishuang Lin ◽  
Qian Du ◽  
Qiang Li ◽  
Ou Wang ◽  
Zhanqi Wang ◽  
...  

3D thermoreversible PNIPAAm-PEG hydrogels are used for scalable production of human pluripotent stem cell-derived vascular smooth muscle cells.


1998 ◽  
Vol 4 (S2) ◽  
pp. 438-439
Author(s):  
R.A. Horowitz ◽  
C.M. Powers ◽  
P. Valero ◽  
R. Craig

Smooth muscle is a machine consisting of working and supporting elements whose structure and 3D organization must be elucidated for the mechanics of shortening and tension generation to be understood. Based on longitudinal and serial transverse sections of rabbit portal vein it was suggested that the contractile elements of smooth muscle formed “mini-sarcomeres”, analogous to skeletal muscle, containing parallel arrays of 3-5 myosin filaments 1.6-2.2 um long. Observations at the light microscopic level were consistent with this idea. The past decade has seen little further investigation into the in situ ultrastructure of this or other smooth muscles, and the general applicability of these findings remains unknown. We have taken advantage of recent methodological advances, which can provide full 3D computer representations of cellular organization based on EM data, using guinea pig taenia coli muscle as a model system.Serial transverse sections (Fig 1) were used to generate 3D reconstructions of the organization of the myosin filaments and their relation to dense bodies, actin bundles, mitochondria and other organelles.


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