BACKGROUNDTelocytes (TCs) are a novel type of interstitial cells, which have been recently described in a large variety of cavitary and noncavitary organs. TCs have small cell bodies, and remarkably thin, long, and moniliform prolongations called telopodes (Tps). Until now, TCs have been found in various loose connective tissues surrounding the arterioles, venules, and capillaries, but as a histological cellular component, whether TCs exist in large arteries remains unexplored.

METHODSTCs were identified by transmission electron microscope in the aortic arch of male C57BL/6 mice.

RESULTSTCs in aortic arch had small cell bodies (length: 6.06-13.02 μm; width: 1.05-4.25 μm) with characteristics of specific long (7.74-39.05 μm), thin, and moniliform Tps; TCs distributed in the whole connective tissue layer of tunica adventitia: TCs in the innermost layer of tunica adventitia, located at the juncture between media and adventitia, with their long axes oriented parallel to the outer elastic membrane; and TCs in outer layers of tunica adventitia, were embedded among transverse and longitudinal oriented collagen fibers, forming a highly complex three-dimensional meshwork. Moreover, desmosomes were observed, serving as pathways connecting neighboring Tps. In addition, vesicles shed from the surface of TCs into the extracellular matrix, participating in some biological processes.

CONCLUSIONSTCs in aorta arch are a newly recognized complement distinct from other interstitial cells in large arteries, such as fibroblasts. And further biologically functional correlations need to be elucidated.

Adventitia ; cytology ; Animals ; Aorta ; cytology ; Aorta, Thoracic ; cytology ; Cell Communication ; physiology ; Connective Tissue Cells ; cytology ; ultrastructure ; Male ; Mice ; Mice, Inbred C57BL ; Microscopy, Electron, Transmission

OBJECTIVESTo investigate the method of preparing porcine thoracic aortas acellular tissue matrix (ACTM) by trypsin, EDTA and Triton X-100 and to find the best concentration of X-100.

METHODSA total of 56 roots of fresh thoracic aortas (without adventitial tissue) from 80 kg-100 kg tame pigs were divided randomly into > groups, each containing 8 roots. Every vessel was put into a 50 ml centrifugal tube with a solution of 0.1% trypsin + 0.02EDTA in PBS for 24 h. After that, each group was separately immerged into a solution of 0.1%, 0.2%, 0.5%, 1.0%, 2.0%, 5.0%, 10.0% Triton X-100 for 144 h-240 h. Specimens were taken every 6 h. Specimens were stained with haematoxylin-eosin and observed grossly under the light and transmission electron microscopy.

RESULTSLight and transmission electron microscopy revealed that ACTM was composed of insoluble collagen, elastin, and some insoluble metamorphic organelles. The best concentration of Triton X-100 was 1% at the time of 176.25 h +/- 5.5 h.

CONCLUSIONSPorcine thoracic aortas ACTM can be obtained successfully through this procedure. Triton X-100 is a good reagent for preparing vessel ACTM.

Animals ; Aorta, Thoracic ; cytology ; surgery ; ultrastructure ; Blood Vessel Prosthesis ; Octoxynol ; pharmacology ; Swine ; Tissue Engineering ; methods

Our previous study demonstrated that TGF-beta1 could induce the differentiation of vascular adventitial fibroblasts (AFs) to myofibroblasts (MFs). The aim of this study was to identify the genes which might be responsible for the cell phenotypic change using genechips. Cultured rat AFs were treated with TGF-beta1 (10 ng/ml) for 0 min, 5 min, 15 min, 2 h, 12 h and 24 h, respectively. Then the cells were gathered to prepare total RNA. We examined TGF-beta1-induced gene expression profiling using Affymetrix oligonucleotide microarrays and analyzed data by GCOS1.2 software. Moreover, expressional similarity was measured by hierarchical clustering. Some of genechip results were confirmed by real-time quantitative RT-PCR. Microarray analysis identified 2121 genes with a 2-fold change or above after TGF-beta1 stimulation. 1318 genes showed a greater than 2-fold increase and 761 genes were reduced 2 folds or more at mRNA levels, whereas a small portion of the total regulated genes (42 genes) displayed dynamically up- and down-regulated pattern. Genes were further segregated for early (peak at 5 min, 15 min and/or 2 h), late (peak at 12 h and/or 24 h), and sustained (2-fold change or above at five time points) temporal response groups according to the time of their peak expression level. Among 1318 up-regulated genes, 333 genes (25.3%) responded rapidly to TGF-beta1 and 159 genes (12.1%) responded in a sustained manner. Most genes (826, 62.6%) were regulated at 12 h or later. For the 761 down-regulated genes, numbers of early and late responsive genes were 335 (44%) and 267 (36.1%), respectively. There were also 159 genes, 19.9% of total down-regulated genes, decreased at five time points treated by TGF-beta1. The results suggested that the gene expressions of secreted phosphoprotein 1 (APP1) and Rho-associated coiled-coil forming kinase 2 (ROCK2) had the same trends as alpha-smooth muscle-actin, a marker of MF differentiation. In addition, the gene expression of potassium voltage-gated channel, Shal-related family and member 2 (KCND2) was up-regulated. Furthermore, it was found that endothelin 1 (EDN1), some complement components, NADPH oxidase 4 (NOX4) and NAD(P)H dehydrogenase, quinone 1 (NQO1) might be involved in MF differentiation. Using microarrary technique, we confirmed some genes that have been identified by other techniques were implicated in MF differentiation and observed new genes involved in this process. Our results suggest that gene expression profiling study is helpful in identifying genes and pathways potentially involved in cell differentiation.
Adventitia ; cytology ; Animals ; Aorta, Thoracic ; cytology ; Cell Transdifferentiation ; genetics ; Cells, Cultured ; Female ; Fibroblasts ; cytology ; Gene Expression Profiling ; Gene Expression Regulation ; Male ; Myofibroblasts ; cytology ; Rats ; Rats, Sprague-Dawley

The aim of the present study was to investigate the role of caveolin-1 in the inhibition of endothelin-1 induced proliferation of vascular smooth muscle cells (VSMCs) by 17beta-estradiol. In the cultured rat thoracic aortic VSMCs, proliferation of VSMCs was determined by using [(3)H]-thymidine incorporation and the expression of caveolin-1 protein was measured by immunofluorescence assays and Western blotting. The measurement demonstate VSMCs exposed to various concentrations of endothelin-1 (1-100 nmol/L) for 24 h induced an increase in [(3)H]-thymidine incorporation. Pretreament with various concentrations of 17beta-estradiol (0.1-10 nmol/L) for 24 h inhibited the proliferation effect of endothelin-1. Immunofluorescence assays showed that after 24 h treatment of VSMCs with endothelin-1 (100 nmol/L), the expression of caveolin-1 in VSMCs was significantly increased, whereas pretreament with 17beta-estradiol (10 nmol/L) for 24 h inhibited the effect. Western blotting results further proved that endothelin-1 inhibited and 17beta-estradiol increased the expression of caveolin-1 in VSMCs. These results demonstrate that 17beta-estradiol inhibits the VSMCs proliferation induced by endothelin-1, and that the effect of estradiol is probably mediated by caveolin-1.
Animals ; Aorta, Thoracic ; cytology ; Caveolin 1 ; physiology ; Cell Division ; Cells, Cultured ; Endothelin-1 ; antagonists & inhibitors ; physiology ; Estradiol ; pharmacology ; Muscle, Smooth, Vascular ; cytology ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo investigate the effect of Astragalus membranaceus(AM) on vascular circles and the underlying mechanisms.

METHODSThe study was performed with the model of isolate rat thoracic aorta rings in organ bath. When the endothelium of rat thoracic aorta was removed,the effect of accumulated AM on aorta rings in resting tension, or pre-constricted with KCl, or pre-constricted with phenylephrine (PE) was observed. And to explove the mechanism, the aorta rings were incubated with Ca(2+)-free medium alone, or Ca(2+)-free medium plus heparin, or propranolol alone before pre-contraction with PE.

RESULTSAM had no significant effects on aorta rings in resting tension or pre-constricted with KCl. When the concentration of AM was cumulated to 10(-1), 3 x 10(-1),10(0), 3 x 10(0) g/L, it caused concentration-dependent relaxation while aorta rings were pre-constricted with PE(3 x 10(-7)mol/L), compared with the control [(90.4 +/-4.2)% compared with (94.7 +/-2.4)%,(86.1 +/-5.0)% compared with (92.6 +/-3.2)%, (82.3 +/-5.9)% compared with (90.4 +/-3.6) %, (78.3 +/-6.0)% compared with (88.1 +/-4.0)%]. This effect was not inhibited by Ca(2+)-free medium or propranolol alone. However, the effect was attenuated by the co-incubation with heparin and Ca(2+)-free medium [without heparin:(76.2+/-4.3)% compared with (92.3 +/-5.9)%, with heparin: (95.3+/-0.5)% compared with (95.1+/-0.6)%].

CONCLUSIONThe results indicate that AM can relax the rat thoracic aorta rings without endothelium. The mechanism may include the inhibition of intracellular calcium ions release by the 1,4,5-triphosphate inositol-receptor-dependent pathway in vascular smooth muscle cells.

Animals ; Aorta, Thoracic ; cytology ; Astragalus membranaceus ; Calcium ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; In Vitro Techniques ; Male ; Muscle, Smooth, Vascular ; cytology ; Phosphatidylinositols ; metabolism ; Rats ; Rats, Sprague-Dawley ; Vasodilator Agents ; pharmacology

The purpose of this study was to clarify the characteristics of the pacemaker cells in the left ventricular outflow tract (aortic vestibule) and compare them with those of the cells in the sinoatrial node (SAN). By using conventional intracellular microelectrode technique to record their action potentials, some ionic channel blockers were used to observe their electrophysiological effects on the two types of pacemaker cells in the rabbit, especially on the ionic movement during phase 0 and phase 4. The results obtained are as follows. (1) Perfusion with 1 micromol/L verapamil (VER) resulted in a significant reduction in the amplitude of action potential (APA), maximal rate of depolarization (V(max)), absolute value of the maximal diastolic potential (MDP), velocity of diastolic depolarization (VDD) and rate of pacemaker firing (RPF), and also a prolongation of the 90% of the duration of action potential (APD(90)) in the pacemaker cells of the SAN and aortic vestibule (P<0.05). (2) Perfusion with 180 micromol/L nickel chloride (NiCl2) resulted in a decrease in VDD in the two types of the pacemaker cells (P<0.01). APA, V(max) and RPF fell notably, and the APD(90) prolonged in the sinoatrial node cells (P<0.05). (3) 2 mmol/L 4-aminopyridine (4-AP) led to a increase in VDD in both types of pacemaker cells (P<0.01). At the same time the absolute values of MDP, APA and V(max) decreased significantly, and APD(90) prolonged notably (P<0.05). During the perfusion, RPF in SAN increased markedly, while RPF in aortic vestibule exhibited no significant change. (4) 2 mmol/L cesium chloride (CsCl) led to a decrease in VDD and RPF in the two types of the pacemaker cells (P<0.05).These results suggested: (1) the ion currents in phase 0 and phase 4 of depolarization and repolarization of slow-response activity in aortic vestibule are similar to those in dominant pacemaker cells of sinoatrial node; (2) for the pacemaker cells in the left ventricular outflow tract, Ca(2+) current is the main depolarizing ion current of the phase 0, K(+) current is the main factor responsible for the repolarization. Attenuation of K(+) current is responsible for the phase 4 spontaneous depolarization. In addition, it seems that I(Ca-T), I(Ca-L) and I(f ) play some role in the pacemaker currents.
4-Aminopyridine ; pharmacology ; Action Potentials ; drug effects ; Animals ; Aorta, Thoracic ; cytology ; physiology ; Female ; Male ; Nickel ; pharmacology ; Periodicity ; Rabbits ; Sinoatrial Node ; cytology ; physiology ; Verapamil ; pharmacology

This study evaluated the biological stability and cytotoxicity of rabbit thoracic aorta cross-linked by dye-mediated photooxidation in vivo environment of blood flow. Rabbits, whose allogenic thoracic aorta was cross-linked by dye-mediated photooxidation (DMP, n=6) and glutaraldehyde (GA, n=6), were in the DMP group and GA group, respectively; rabbits, whose homogenic abdominal aorta was orthotopic transplanted (OT, n=6), were in the OT group. Then the donor arteries were transplanted into the position of the abdominal arteries of rabbits. After operation, the animals were fed for 1 month, then each of graft arteries was removed for observation. Biological stability was evaluated through histological analysis under optical microscope. Cytotoxicity was evaluated through ratio of coverage of endothelial cell (ES) under scanning-electron microscope. The results showed that no statistically significant difference was noted between DMP group and OT group (P>0.05); however, there was a significant difference between DMP group and GA group (P<0.01). The stability index in DMP group was much higher than that in GA group. There was a statistically significant difference between DMP group and GA group (P<0.01). Ratio was much higher in DMP group than in GA group. In conclusion, the arteries cross-linked by dye-mediated photooxidation treatment appeared to have higher biological stability and lower cytotoxicity in rabbit allogenic transplation model.
Animals ; Aorta, Abdominal ; transplantation ; Aorta, Thoracic ; cytology ; drug effects ; surgery ; Bioprosthesis ; Blood Vessel Prosthesis ; Coloring Agents ; chemistry ; Cross-Linking Reagents ; Endothelial Cells ; cytology ; Female ; Male ; Oxidants, Photochemical ; pharmacology ; Oxidation-Reduction ; Photochemistry ; Rabbits ; Random Allocation

OBJECTIVETo investigate the vasorelaxation effect of emodin and its relationship with NO-cGMP signal pathway.

METHODSChanges of tension of rat thoracic aortic rings were measured by MedLab biologic signal collection system, and the activity of total nitric oxide synthase (tNOS), constitutive NOS (cNOS) and inducible NOS (iNOS) in endothelium after being treated with emodin was determined with nitric acid reductase method.

RESULTSEmodin relaxed the phenylephrine and potasium chlorate induced contraction of aortic rings, either with or without intact endothelium, in a concentration-dependent manner. Pretreatment of no-specific potassium channel blocker strontium chloride (CsCL) could attenuate the vasorelaxation effect of emodin on aortic rings without intact endothelium, but it could not inhibit vasorelaxation of emodin on aortic rings with intact endothelium. This vasorelaxation action of emodin (40 micromol/L) could be partial blocked by NOS inhibitor L-NAME and guanylate cyclase inhibitor ODQ, with the vasorelaxation range dropped to 64.76 +/- 13.73% and 6.28 +/- 4.79% respectively. Moreover, emodin (40 micromol/L) increased iNOS activity significantly.

CONCLUSIONThe concentration-dependent vasorelaxation effect of emodin might act by activating the NO-cGMP pathway in vascular endothelium.

Animals ; Aorta, Thoracic ; cytology ; Cyclic GMP ; metabolism ; Emodin ; pharmacology ; Endothelium, Vascular ; metabolism ; Male ; Nitric Oxide ; metabolism ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; Vasodilator Agents ; pharmacology

OBJECTIVETo investigate the effect of P. notoginseng on vascular smooth muscle cell (VSMC) proliferation induced by hyperlipidemia serum.

METHODMTT method was used to investigate the effect of hyperlipidemia serum and hyperlipidemia plus P. notoginseng on VSMC proliferation.

RESULTHyperlipidemia serum could promote VSMC proliferation significantly as compared with the control group (P < 0.05), while hyperlipidemia plus P. notoginseng could weaken this effect significantly (P < 0.05).

CONCLUSIONP. notoginseng can significantly inhibit the VSMC proliferation induced by hyperlipidemia serum.

Animals ; Aorta, Thoracic ; cytology ; Cell Proliferation ; drug effects ; Cells, Cultured ; Drugs, Chinese Herbal ; isolation & purification ; pharmacology ; Hyperlipidemias ; blood ; Male ; Muscle, Smooth, Vascular ; cytology ; Myocytes, Smooth Muscle ; cytology ; Panax notoginseng ; chemistry ; Plants, Medicinal ; chemistry ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Serum

OBJECTIVETo compare the chemical components in Baishao and Chishao water extracts and investigate their effects on the proliferation of rat thoracic aorta smooth muscle cells in vitro.

METHODSThe contents and chemical structures of monomers separated from the water extracts of Baishao and Chishao were analyzed using high-performance liquid chromatography and mass spectroscopy. Rat thoracic aorta smooth muscle cell line A7r5 and its platelet-derived growth factor-BB (PDGF-BB)-induced proliferation model were exposed to different concentrations of Baishao and Chishao water extracts, and the cell viability was analyzed by mitochondrial-dependent reduction of MTT and real-time cell analyzer.

RESULTSThe growth of A7r5 cells was significantly stimulated by 300 µg/ml Baishao water extract (P<0.01), but Chishao water extract produced no such effect (P>0.05). In PDGF-BB-induced cell proliferation model, the cell growth was significantly suppressed by 100-500 µg/ml Chishao water extract (P<0.01), while Baishao water extract showed no obvious effect on the cell proliferation (P>0.05).

CONCLUSIONBaishao and Chishao water extracts have different chemical components and produce different biological effects.

Animals ; Aorta, Thoracic ; cytology ; Cell Line ; Cell Proliferation ; drug effects ; Drugs, Chinese Herbal ; isolation & purification ; pharmacology ; Muscle, Smooth, Vascular ; cytology ; Myocytes, Smooth Muscle ; cytology ; drug effects ; Paeonia ; chemistry ; Plants, Medicinal ; chemistry ; Proto-Oncogene Proteins c-sis ; pharmacology ; Rats