scholarly journals Electron Microscope Study of the Lathyritic Rat Aorta

1960 ◽  
Vol 7 (3) ◽  
pp. 539-545 ◽  
Author(s):  
M. K. Keech
Keyword(s):  
Smooth Muscle ◽  
Electron Microscope ◽  
Morphological Changes ◽  
Muscle Cells ◽  
Progressive Increase ◽  
Rat Aorta ◽  
Aortic Aneurysms ◽  
Weanling Rats ◽  
Lead Hydroxide ◽  
Elastic Laminae

Six weanling rats were fed a diet containing 0.4 per cent BAPN fumarate and sacrificed after 5 to 33 days on the diet. The ascending aortae were fixed with OsO4, embedded in methacrylate and araldite, sectioned, stained with lead hydroxide, and examined with the electron microscope. The descending thoracic aortae were examined by light microscopy. Compared with pair-fed controls, the experimentals showed definite changes which became more marked as the disease progressed. The wall became thicker with wider interlaminar spaces, radial orientation of the smooth muscle cells, progressive loss of desmosomes, and progressive increase in a dense, finely stippled material that coated the edges of the elastic laminae and extended outwards between the muscle cells and separated the ends of these cells from the laminae. This stippled material occurred at the same sites as the increase in PAS-positive and azan-positive material seen with the light microscope. There was an increase in subendothelial and interlaminar collagen, and electron microscopy clearly showed that the cells were smooth muscle and not fibroblasts. The possible bearing of the morphological changes on the formation of aortic aneurysms is discussed.

scholarly journals Electron Microscope Study of the Normal Rat Aorta

1960 ◽  
Vol 7 (3) ◽  
pp. 533-537 ◽  
Author(s):  
M. K. Keech
Keyword(s):  
Smooth Muscle ◽  
Fine Structure ◽  
Electron Microscope ◽  
Cross Section ◽  
Electron Microscope Study ◽  
Rat Aorta ◽  
Endothelial Layer ◽  
Signet Ring ◽  
Normal Rat ◽  
Elastic Laminae

The fine structure of the normal rat aorta is described. The presence of a sub-endothelial layer, the oblique orientation of the smooth muscle cells with respect to the aortic axis, and the occurrence of desmosomes between these cells and adjacent elastic laminae, are emphasized. Lead-stained collagen presented a characteristic signet-ring appearance on cross-section. The rats examined were the pair-fed controls for the lathyritic series described in a separate communication.

scholarly journals The Role of Two-Pore Channels in Norepinephrine-Induced [Ca2+]i Rise in Rat Aortic Smooth Muscle Cells and Aorta Contraction

Cells ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 1144 ◽  
Author(s):  
Sergei K. Trufanov ◽  
Elena Yu. Rybakova ◽  
Piotr P. Avdonin ◽  
Alexandra A. Tsitrina ◽  
Irina L. Zharkikh ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Calcium Concentration ◽  
Muscle Cells ◽  
Rat Aorta ◽  
Structural Analogue ◽  
Aortic Smooth Muscle ◽  
Cis And Trans ◽  
High Degree

Second messenger nicotinic acid adenine dinucleotide phosphate (NAADP) triggers Ca2+ release via two-pore channels (TPCs) localized in endolysosomal vesicles. The aim of the present work is to evaluate the role of TPCs in the action of norepinephrine (NE), angiotensin II (AngII), vasopressin (AVP), and 5-hydroxytriptamine (5-HT) on free cytoplasmic calcium concentration ([Ca2+]i) in smooth muscle cells (SMCs) isolated from rat aorta and on aorta contraction. To address this issue, the NAADP structural analogue and inhibitor of TPCs, NED 19, was applied. We have demonstrated a high degree of colocalization of the fluorescent signals of cis-NED 19 and endolysosmal probe LysoTracker in SMCs. Both cis- or trans-NED 19 inhibited the rise of [Ca2+]i in SMCs induced by 100 μM NE by 50–60%. IC50 for cis- and trans-NED 19 were 2.7 and 8.9 μM, respectively. The inhibition by NED 19 stereoisomers of the effects of AngII, AVP, and 5-HT was much weaker. Both forms of NED 19 caused relaxation of aortic rings preconstricted by NE, with relative potency of cis-NED 19 several times higher than that of trans-NED 19. Inhibition by cis-NED 19 of NE-induced contraction was maintained after intensive washing and slowly reversed within an hour of incubation. Cis- and trans-NED 19 did not cause decrease in the force of aorta contraction in response to Ang II and AVP, and only slightly relaxed aorta preconstricted by 5-HT and by KCl. Suppression of TPC1 in SMCs with siRNA caused a 40% decrease in [Ca2+]i in response to NE, whereas siRNA against TPC2 did not change NE calcium signaling. These data suggest that TPC1 is involved in the NE-stimulated [Ca2+]i rise in SMCs. Inhibition of TPC1 activity by NED 19 could be the reason for partial inhibition of aortic rings contraction in response to NE.

Endothelial and smooth muscle cells from the same rat aorta

1991 ◽  
Vol 27 (9) ◽  
pp. 687-688 ◽  
Author(s):  
Ph. Andre ◽  
M. Michel ◽  
C. Schott ◽  
J. C. Stoclet
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Muscle Cells ◽  
Rat Aorta

Abstract 496: Extracellular Matrix Secretion by Vascular Smooth Muscle Cells: Role of MiR-195 and MiR-29b

2014 ◽  
Vol 34 (suppl_1) ◽  
Author(s):  
Anna Zampetaki ◽  
Xiaoke Yin ◽  
Ursula Mayr ◽  
Renata Gomes ◽  
Sarah Langley ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Muscle Cells ◽  
Abdominal Aortic Aneurysms ◽  
Aortic Aneurysms ◽  
Abdominal Aortic ◽  
Vascular Smcs

Rationale: Extracellular matrix (ECM) remodeling is a key function of vascular smooth muscle cells (SMCs). MicroRNAs (miRNAs), in particular the miR-29 family and miR-195, have been implicated in the control of ECM secretion. Objective: To perform a proteomics comparison of miRNA effects on ECM production by vascular SMCs. Methods and Results: Murine SMCs were transfected with miRNA mimics and antimiRs of miR-29b and miR-195, and their conditioned medium was analyzed by mass spectrometry. Both miRNAs targeted a cadre of ECM proteins, including proteoglycans, collagens, proteases, elastin and proteins associated with elastic microfibrils, albeit miR-29 showed a stronger effect. The proteomics findings were subsequently validated at the transcription level using quantitative polymerase chain reaction. Similar to miR-29, in vivo inhibition of miR-195 by intraperitoneal injection of cholesterol bound antagomiRs led to significant alterations of elastin expression in murine aortas. Since elastin degradation is a key event in aortic aneurysm formation, we investigated miR-195 expression in patients. In human aortic aneurysmal tissue, miR-195 expression was reduced compared to non-aneurysmal tissue. In plasma, a comparison between male patients with abdominal aortic aneurysms and controls matched for diabetes and hypertension returned a panel of five highly correlated miRNAs: miR-195, miR-125b, miR-148a, miR-20a and miR-340 showed significant inverse associations with the presence of abdominal aortic aneurysms and aortic diameter, with miR-195 dominating in terms of association strength. Conclusions: Using proteomic analysis, we compared the effect of miR-29 and miR-195 on ECM secretion by vascular SMCs and identified novel miRNA targets. Findings in patients support an important role for miR-195 in vascular remodeling as evidenced by reduced miR-195 expression in human aneurysmal tissue and an inverse correlation between plasma miR-195 levels and aortic diameter.

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