scholarly journals Localization of phospholamban in smooth muscle using immunogold electron microscopy.

1988 ◽  
Vol 107 (2) ◽  
pp. 555-562 ◽  
Author(s):  
D G Ferguson ◽  
E F Young ◽  
L Raeymaekers ◽  
E G Kranias
Keyword(s):  
Electron Microscopy ◽  
Smooth Muscle ◽  
Sarcoplasmic Reticulum ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Polyclonal Antibody ◽  
Muscle Cells ◽  
Immunogold Electron Microscopy ◽  
Cardiac Sarcoplasmic Reticulum

Phospholamban, the putative regulator of the Ca2+-ATPase in cardiac sarcoplasmic reticulum, was immunolocalized in canine visceral and vascular smooth muscle. Gently disrupted tissues were labeled with an affinity-purified phospholamban polyclonal antibody and indirect immunogold, using preembedding techniques. The sarcoplasmic reticulum of smooth muscle cells was specifically labeled with patches of immunogold distributed in a nonuniform fashion, while the sarcolemma did not appear to contain any phospholamban. The outer nuclear envelopes were also observed to be heavily labeled with the affinity-purified phospholamban polyclonal antibody. These findings suggest that phospholamban may play a role in the regulation of cytoplasmic and intranuclear calcium levels in smooth muscle cells.

Preparation of recombinant human-like collagen/fibroin scaffold and its promoting effect on vascular cells biocompatibility

2018 ◽  
Vol 33 (4) ◽  
pp. 416-425 ◽  
Author(s):  
Jia Yan ◽  
Kun Hu ◽  
YongHao Xiao ◽  
Fan Zhang ◽  
Lu Han ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Laser Scanning ◽  
Muscle Cells ◽  
Laser Scanning Confocal Microscopy ◽  
Scanning Confocal Microscopy ◽  
Scanning Electron

A novel recombinant human-like collagen/fibroin scaffold has been prepared previously, which has high porosity, controllable pore size, and much better mechanical properties than the reported fibroin-based scaffold. In this research, the cell responses of vascular smooth muscle cells to this blend scaffold were examined in vitro. Cell morphology, adherence, and growth in scaffolds were observed by scanning electron microscopy, laser scanning confocal microscopy after staining of the cells with propidium iodide at 1, 3, 5, and 7 days, respectively. A wide range of measurements, including 3-[4,5–dimethylthiazol-2-yl]-2, 5-diphenyl tetrasodium bromide assay, and total intracellular protein content at the end of 7 days culture, were conducted. An increase of viability and protein content of vascular smooth muscle cells cultured in recombinant human-like collagen/fibroin scaffold was found. The laser scanning confocal microscopy and scanning electron microscopy results confirm that the cells readily adhered and proliferation in the blend than in fibroin scaffold, and indicate a better adhesion process. The positive effects were especially significant for vascular smooth muscle cells. The recombinant human-like collagen/fibroin scaffold could be a promising biomaterial for vascular tissue engineering.

Thapsigargin stimulates Ca2+ entry in vascular smooth muscle cells: nicardipine-sensitive and -insensitive pathways

1992 ◽  
Vol 262 (5) ◽  
pp. C1258-C1265 ◽  
Author(s):  
Y. T. Xuan ◽  
O. L. Wang ◽  
A. R. Whorton
Keyword(s):  
Smooth Muscle ◽  
Sarcoplasmic Reticulum ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Muscle Cells ◽  
Inositol Polyphosphate ◽  
Inositol Polyphosphates ◽  
Permeabilized Cells ◽  
Inositol 1,4,5 Trisphosphate

We have investigated the role of the sarcoplasmic reticulum Ca2+ pool in regulating Ca2+ entry in vascular smooth muscle cells using a receptor-independent means of mobilizing the intracellular Ca2+ pool. Thapsigargin (TG) has been shown to inhibit the endoplasmic reticulum Ca(2+)-ATPase, mobilize intracellular Ca2+, and activate Ca2+ entry in nonmuscle tissues. When smooth muscle cells were treated with 0.2 microM TG, cytosolic Ca2+ concentrations rose gradually over 8 min to a peak value of 365 +/- 18 nM. Cytosolic Ca2+ remained elevated for at least 20 min and was supported by continued entry of extracellular Ca2+. TG also stimulated entry of Mn2+ and 45Ca2+ from outside the cell. Importantly, TG-induced Ca2+ entry and Mn2+ entry were found to occur through mechanisms that were independent of L-type Ca2+ channel activation because influx was not inhibited by concentrations of nicardipine that were found to block either endothelin- or 100 mM extracellular K(+)-induced cation influx. The mechanism through which TG activates cation entry appears to involve mobilization of the inositol 1,4,5-trisphosphate-responsive intracellular Ca2+ pool. In permeabilized cells, TG prevented ATP-stimulated Ca2+ uptake into the sarcoplasmic reticulum and slowly released sequestered Ca2+. The Ca2+ pool involved was responsive to inositol 1,4,5-trisphosphate. However, TG did not initiate the formation of inositol polyphosphates. Thus TG mobilizes the sarcoplasmic reticulum Ca2+ pool and activates Ca2+ entry through a nicardipine-insensitive Ca2+ channel in vascular smooth muscle. The mechanism is independent of inositol polyphosphate formation.

scholarly journals Waves of Calcium Depletion in the Sarcoplasmic Reticulum of Vascular Smooth Muscle Cells: An Inside View of Spatiotemporal Ca2+ Regulation

PLoS ONE ◽  
2013 ◽  
Vol 8 (2) ◽  
pp. e55333 ◽  
Author(s):  
Mitra Esfandiarei ◽  
Nicola Fameli ◽  
Yohan Y. H. Choi ◽  
Arash Y. Tehrani ◽  
Jeremy G. Hoskins ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Sarcoplasmic Reticulum ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Muscle Cells ◽  
Calcium Depletion ◽  
Inside View

Angiotensin-receptor signaling in cultured vascular smooth muscle cells

1986 ◽  
Vol 250 (5) ◽  
pp. F759-F769 ◽  
Author(s):  
J. B. Smith
Keyword(s):  
Smooth Muscle ◽  
Sarcoplasmic Reticulum ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Slow Component ◽  
Muscle Cells ◽  
Ca Channel ◽  
Ang Ii ◽  
Receptor Stimulation ◽  
Intact Cells

Functional receptors for angiotensin II (ANG II) are present in smooth muscle cells cultured from rat aorta. These cells are especially suitable for investigating transmembrane signaling events, since ANG II-receptor function is consistently expressed for many population doublings in culture. Cytoplasmic free Ca, measured with quin 2 or fura-2, transiently increases after receptor stimulation. ANG II releases Ca that is sequestered intracellularly, since the removal of extracellular Ca does not prevent the hormone from increasing intracellular free Ca. Angiotensin provokes both polyphosphoinositide hydrolysis and phosphatidate-phosphoinositide synthesis. Purified inositol trisphosphate (IP3) releases Ca from a nonmitochondrial organelle, presumably the sarcoplasmic reticulum or a specialized region therein. IP3 probably opens an intracellular Ca channel by a ligand-binding reaction rather than a metabolic reaction. The accumulation of IP3 in intact cells in response to ANG II seems fast enough to cause Ca mobilization. ANG II increases a fast and a slow component of 45Ca2+ efflux from the intact cells. The rapid stimulation of Ca2+ efflux from the cell via a Na-Ca antiporter probably accounts at least in part for the short duration of the increase in cytoplasmic free Ca elicited by angiotensin. ANG II has no effect on a fast component of 45Ca2+ influx but does increase a slow component of 45Ca2+ influx; that increase would help to sustain the elevation in free Ca and the refilling of the sarcoplasmic reticulum. Additionally, ANG II-receptor stimulation depolarizes the cell membrane and increases the specific activities of the Na-K pump, the Na-H antiporter, the Na-Ca antiporter, and the Na-K-Cl cotransporter. Ca and/or 1,2-diacylglycerol, the lipophilic activator of protein kinase C, which is concomitantly produced along with IP3, may mediate the effects of ANG II on Na and K transport. Investigations of cultured vascular smooth muscle support the inositol-signaling hypothesis of hormone action.

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