Role and mechanism of PKCs in midazolam-induced relaxation of aortic smooth muscle in spontaneously hypertensive rats / 中国药理学通报

Aim To investigate the effect of protein kinase C (PKCs) on midazolam-induced relaxation of aortic smooth muscle in spontaneously hypertensive rats (SHR) and the underlying mechanism. Methods U-sing the isolated vessel tension measurement system, the relaxant effect of midazolam on aortic smooth muscle of SHR and Wistar-Kyoto (WKY) rats was observed. After preincubation with GF109203X (GF, a broad-spectrum inhibitor of PKCs), LY333531 (LY, PKCp2 specific inhibitor) and PKC6 pseudo-substrate inhibitor (PPS), the changes of midazolam-induced relaxation amplitude were observed. Western blot was used to detect the effect of midazolam on the phosphorylation level of PKC [32 in SHR aortic smooth muscle. The effect of midazolam, LY, GF and PPS on the phosphorylation level of the key proteins (CPI-17/ MYPT1/MLC) in calcium sensitization pathway in SHR aortic smooth muscle was also examined. Results Midazolam concentration-dependently relaxed aortic smooth muscle in SHR and WKY. GF significantly inhibited midazolam-induced relaxation amplitude of SHR and WKY aortic smooth muscle. LY and PPS had no significant effect on midazolam-induced relaxation amplitude of WKY aortic smooth muscle. In contrast, LY markedly inhibited midazolam-induced relaxation amplitude of SHR aortic smooth muscle. Midazolam significantly inhibited the phosphorylation level of PKC [32 enhanced by NE in SHR aortic smooth muscle. Midazolam, LY and GF all evidently inhibited the phosphorylation level of the key proteins in calcium sensitization pathway enhanced by NE in SHR aortic smooth muscle. Conclusions Midazolam induces excessive relaxation of SHR aortic smooth muscle by inhibiting calcium sensitization pathway mediated by PKC [32.

Expression of tropomyosin 2 in aortic dissection tissue / 中华心血管病杂志

Objective: To investigate the expression pattern of tropomyosin 2(TPM2) in aorta of patients with aortic dissection and explore its clinical implication. Methods: Thirteen cases with acute type A aortic dissection(TAAD) diagnosed by transabdominal aortic angiography from 2015 in Tongji Hospital were included. During the operation, the aortic wall tissues of these patients were collected. Ten patients with heart transplantation were selected as control group, and normal aortic wall tissues were taken. The hematoxylin-eosin (HE) and Verhoeff's Van Gieson (EVG) staining were performed to observe the morphological changes of aorta. The mRNA expression level of TPM2 was measured by real-time fluorescent quantitative-PCR, and the protein levels of TPM2 were detected by Western blot and immunohistochemical staining. Image The J software was used to collect the optical density values of each point on the image, obtain the integrated optical density(IOD) value, and calculate the average density(%, IOD/area of the target distribution area). Results: HE and EVG staining revealed medial degeneration and broken elastic fiber in aorta of TAAD patients. The mRNA expression levels of TPM2 were significantly upregulated in aorta of TAAD patients as compared to the control group (P<0.05), so as the TPM2 protein expression levels ((9.73±1.20)% vs. (0.11±0.04)%, P<0.05). And TPM2 was mainly expressed in cytoplasm. Conclusion: The increased expression of TPM2 in TAAD patients hints that TPM2 might be involved in the pathogenesis of aortic dissection.

Influence of influenza A and B virus infections on human aortic smooth muscle cells and the expressions of cytokines / 医学研究生学报

Objective　Vascular smooth muscle cells are the main cells in atherosclerosis. Reports are rarely seen on influenza virus infection on human aortic smooth muscle cells (HASMC) and its influence on the expressions of the related cytokines. This study was to investigate the impact of influenza A virus (IAV) and influenza B virus (IBV) infection on HASMCs and the expressions of cytokines. Methods　HASMCs were stimulated with IAV or IBV or not stimulated with virus (the control). The nucleoprotein of the influenza virus in the cells was detected by immunofluorescence assay, the proliferation of the cells determined with CCK8, and the level of influenza virus RNA in the supernatant measured by qPCR. The collected supernatant was used to infect Madin-Darby canine kidney (MDCK) cells and detect the influenza virus nucleoprotein. The expressions of the cytokines of the influenza virus after 24 hours of infection were determined by qPCR.　Results　At 3 and 4 days after infected with influenza virus, the proliferation of the HASMCs was significantly inhibited in the IAV and IBV groups as compared with the control (P<0.05). The expression of virus RNA in the supernatant of the IBV group at 3 days was 5.75 times as high as that at 2 days (P<0.05), dropped at 4 days but still higher than that at 2 days (P<0.01). Compared with the normal culture medium, the medium with virus growth fluid significantly elevated the RNA level of IAV (0.842±0.148 vs 15.182±1.932, P< 0.01) and IBV (0.962±0.033 vs 4.029±0.681, P<0.01). After infection, the expression of MCP-1 was remarkably up-regulated in the IAV and IBV groups (4.364±0.193 and 3.348±0.507) in comparison with that in the control group (1.001±0.001) (P<0.05), and so were the expressions of IL-6 and TNF-α (P<0.05).　Conclusion　Both IAV and IBV can infect HASMCs and increase the expressions of the cytokines MCP-1, IL-6 , and TNF-α.

Effect of ghrelin on proliferation and mitofusin-2 expression of human aortic smooth muscle cells / 重庆医学

Objective To investigate the effects of ghrelin on proliferation of vascular smooth muscle cells(VSMC)and the expression of mitochondrial fusion 2(Mfn-2)in cultured human aortic smooth muscle cells(HASMCs).Methods HASMCs were cultured in vitro,treated with different concentrations(10-9,10-8,10-7,10-6,10-5 mol/L)ghrelin or 10-6 mol/L ghrelin for different time(0,6,12,18,24 h).Subconfluent HASMCs at passage 4-6 were used in experiments.MTT essay was used to investigate the effect on proliferation of HASMCs.RT-PCR and Western blot were used to analyse the expression of Mfn-2.Results 10-7-10-5 mol/L ghrelin inhibited the proliferation of HASMCs,and the inhibitory effect of concentration of 10-6 mol/L was the most obvious(P<0.01).Ghrelin inhibited the proliferation of HASMCs in 6-24 h,and it reached the peak at 24 h(P<0.01).10-6 mol/L ghrelin significantly increased the expression of Mfn-2 mRNA and protein(P<0.01).The up-regulation of 10-6 mol/L ghrelin on Mfn-2 mRNA and protein expression reached the peak at 18 h(P<0.01).Conclusion Ghrelin might inhibit the proliferation of HASMC by up-regulating the expression of Mfn-2.

Expression and biological functions of Myc associated factor X in human aortic dissection tissue / 第二军医大学学报

Objective To observe the expression of Myc associated factor X (MAX) in aortic dissection tissue, and to discuss its biological functions. Methods MAX expression level was evaluated by qRT-PCR and Western blotting analysis in 15 dissected aorta samples. The adenovirus vector was used to transfect human aortic smooth muscle cells (HASMCs) for overexpression of MAX. The effects of MAX overexpression on proliferation and apoptosis of HASMCs were analyzed by Cell Counting Kit-8 and flow cytometry, respectively. Results MAX mRNA and protein expression levels were significantly higher in the aortic dissection tissue compared with that in the healthy controls. Overexpression of MAX significantly inhibited the proliferation of HASMCs and promoted its apoptosis (P<0.05). Conclusion MAX might induce the loss of HASMCs via regulating their proliferation and apoptosis process, thus play an important role in the development and progression of aortic dissection.

Effect of calcium phosphate crystals induced by uremic serum on calcification of human aortic smooth muscle cells / 中华肾脏病杂志

Objective To investigate the impact of calcium phosphate crystals induced by uremic serum on calcification of human aortic smooth muscle cells (HASMCs).Methods Uremic serum was incubated at 37℃ for 3 days.Calcium phosphate crystals and uremic supernatant were isolated from uremic serum by uhracentrifugation.Scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDX) were performed for analysis of morphological and chemical characteristics of the crystals.HASMCs were treated in vitro with control medium,uremic serummedium,calcium phosphate crystals-medium and uremic supernatant-medium.Calcification was visualizcd by Alizarin red staining.Calcium loads in cells were quantified by o-cresolphthalein complexone method.Gene expression of bone morphogenetic protein-2 (BMP-2),osteopontin (OPN) and core-binding factor α1 (Cbfα1),alkaline phosphate (ALP) and matrix gamma carboxyglutamic acid protein (MGP) were quantified by real-time PCR.Cbfα1,OPN and BMP-2 protein levels were determined by Western blotting or ELISA.Results Calcium phosphate crystals which induced by uremic serum displayed laminated shapes containing crystallized needle-like projections and ranged from 30-500 nm,with Ca/P ratios of 1.41 ±0.05.Compared with the cells in control group,uremic serum induced HASMCs calcification,increased calcium loads (P ＜ 0.05),up-regulated BMP-2,OPN,Cbfα1 mRNA and protein expression (all P＜ 0.01).Similar to uremic serum,calcium phosphate crystals also induced HASMCs calcification,increased calcium loads (P＜0.05),and up-regulated BMP-2,OPN,Cbfα1 mRNA and protein expression (all P ＜ 0.01).However,there was no significant difference between HASMCs growing in uremic supernatant and control medium in calcium loads or the expression levels of these osteogenic proteins (P ＞ 0.05).Conclusions Calcium phosphate crystals induced by uremic serum promote HASMCs calcification,which might be one of the mechanisms of uremic vascular calcification.

Alteration of Ryanodine-receptors in Cultured Rat Aortic Smooth Muscle Cells

Vascular smooth muscle cells can obtain a proliferative function in environments such as atherosclerosis in vivo or primary culture in vitro. Proliferation of vascular smooth muscle cells is accompanied by changes in ryanodine receptors (RyRs). In several studies, the cytosolic Ca2+ response to caffeine is decreased during smooth muscle cell culture. Although caffeine is commonly used to investigate RyR function because it is difficult to measure Ca2+ release from the sarcoplasmic reticulum (SR) directly, caffeine has additional off-target effects, including blocking inositol trisphosphate receptors and store-operated Ca2+ entry. Using freshly dissociated rat aortic smooth muscle cells (RASMCs) and cultured RASMCs, we sought to provide direct evidence for the operation of RyRs through the Ca2+- induced Ca2+-release pathway by directly measuring Ca2+ release from SR in permeabilized cells. An additional goal was to elucidate alterations of RyRs that occurred during culture. Perfusion of permeabilized, freshly dissociated RASMCs with Ca2+ stimulated Ca2+ release from the SR. Caffeine and ryanodine also induced Ca2+ release from the SR in dissociated RASMCs. In contrast, ryanodine, caffeine and Ca2+ failed to trigger Ca2+ release in cultured RASMCs. These results are consistent with results obtained by immunocytochemistry, which showed that RyRs were expressed in dissociated RASMCs, but not in cultured RASMCs. This study is the first to demonstrate Ca2+ release from the SR by cytosolic Ca2+ elevation in vascular smooth muscle cells, and also supports previous studies on the alterations of RyRs in vascular smooth muscle cells associated with culture.

Native Low-Density Lipoprotein-Dependent Interleukin-8 Production Through Pertussis Toxin-Sensitive G-Protein Coupled Receptors and Hydrogen Peroxide Generation Contributes to Migration of Human Aortic Smooth Muscle Cells

PURPOSE: Stimulation of human aortic smooth muscle cells (hAoSMCs) with native low-density lipoprotein (nLDL) induced the production of interleukin-8 (IL-8) that is involved in the pathogenesis of cardiovascular diseases. However, the process of signal transduction of nLDL was currently uncharacterized. Therefore, the aim of this study was to investigate the signal transduction pathway of nLDL-dependent IL-8 production and the effect of IL-8 on hAoSMCs migration. MATERIALS AND METHODS: nLDL was prepared by ultracentrifugation with density-adjusted human serum of normocholesterolemia. In hAoSMCs, IL-8 secreted to medium was measured using ELISA assay, and Western blot analysis was performed to detect p38 MAPK activation as a key regulator of IL-8 production. nLDL-dependent H2O2 generation was determined by microscopic analysis using 2',7'-dichlorofluoroscein diacetate (DCF-DA). IL-8-induced migration of hAoSMCs was evaluated by counting the cell numbers moved to lower chamber using Transwell plates. RESULTS: nLDL-induced IL-8 production was completely blocked by preincubation of hAoSMCs with pertussis toxin (PTX), which inhibited nLDL-dependent p38 MAPK phosphorylation. PTX-sensitive G-protein coupled receptor was responsible for nLDL-dependent H2O2 generation that was abrogated with preincubation of the cells with of polyethylene glycol-conjugated catalase (PEG-Cat). Pretreatment of PEG-Cat prevented nLDL-induced p38 MAPK phosphorylation and IL-8 production, which was partly mimicked by treatment with exogenous H2O2. Finally, IL-8 increased hAoSMCs migration that was completely blocked by incubation with IL-8 neutralizing antibody. CONCLUSION: PTX-sensitive G-protein coupled receptor-dependent H2O2 generation by nLDL plays a critical role in IL-8 production in hAoSMC, and IL-8 may contribute to atherogenesis through increased migration of hAoSMCs.

Tetrahydrobiopterin Inhibits PDGF-stimulated Migration and Proliferation in Rat Aortic Smooth Muscle Cells via the Nitric Oxide Synthase-independent Pathway

Tetrahydrobiopterin (BH4), an essential cofactor for nitric oxide synthase (NOS) activity, is known to play important roles in modulating both NO and superoxide production during vascular diseases such as atherosclerosis. However, the role of BH4 in functions of vascular smooth muscle cells is not fully known. In this study, we tested the effects of BH4 and dihydrobiopterin (BH2), a BH4 precursor, on migration and proliferation in response to platelet-derived growth factor-BB (PDGF-BB) in rat aortic smooth muscle cells (RASMCs). Cell migration and proliferation were measured using a Boyden chamber and a 5-bromo-2'-deoxyuridine incorporation assay, respectively, and these results were confirmed with an ex vivo aortic sprout assay. Cell viability was examined by 2,3-bis [2-methoxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide assays. BH4 and BH2 decreased PDGF-BB-induced cell migration and proliferation in a dose-dependent manner. The inhibition of cell migration and proliferation by BH4 and BH2 was not affected by pretreatment with N G-nitro-L-arginine methyl ester, a NOS inhibitor. Moreover, the sprout outgrowth formation of aortic rings induced by PDGF-BB was inhibited by BH4 and BH2. Cell viability was not inhibited by BH4 and BH2 treatment. The present results suggest that BH4 and BH2 may inhibit PDGF-stimulated RASMC migration and proliferation via the NOS-independent pathway. Therefore, BH4 and its derivative could be useful for the development of a candidate molecule with an NO-independent anti-atherosclerotic function.

Native low-density lipoprotein-induced superoxide anion contributes to proliferation of human aortic smooth muscle cells / 대한마취과학회지

BACKGROUND: Native low-density lipoprotein (nLDL) was one of the modifiable risk factors contributed directly to cardiovascular diseases development. We investigated that nLDL stimulation induced NADPH oxidase activation and superoxide production that was an important factor on human aortic smooth muscle cells (hAoSMC) proliferation. METHODS: Superoxide generation was recorded with fluorescent-staining of dihydroethidine or by measuring lucigenin-induced chemiluminescence for 5 minutes. We examined cell proliferation with 4[-3-(4-iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate (WST-1) reagent and analyzed the change of gene expression by northern blot analysis. RESULTS: nLDL stimulation increased superoxide anion production in hAoSMC that confirmed through dihydroethidine staining and lucigenin-induced chemiluminescence methods. nLDL-induced proliferation abolished with preincubation of superoxide scavengers or NADPH oxidase inhibitor. NADPH as a substrate of NADPH oxidase increased superoxide generation in both nLDL-stimulated and unstimulated cell homogenate, which was completely blocked at the diphenylene iodinium (DPI)- or apocynin-pretreated hAoSMC homogenates. Furthermore, superoxide generation was only observed at the fraction of cellular precipitate, but not in soluble fraction. Expression of p22phox in mRNA level increased with nLDL treatment as early as 30 minutes and transfection of anti-sense oligonucleotide of p22phox completely abolished nLDL-induced proliferation of hAoSMC. CONCLUSIONS: The above results have shown that nLDL-induced proliferation in hAoSMC depends on superoxide production through NADPH oxidase activation.

Olibanum Extract Inhibits Vascular Smooth Muscle Cell Migration and Proliferation in Response to Platelet-Derived Growth Factor

Olibanum (Boswellia serrata) has been shown to have anti-inflammatory, anti-arthritic and anti- cancer effects. This study determined the role of a water extract of olibanum in platelet-derived growth factor (PDGF)-stimulated proliferation and migration of rat aortic smooth muscle cells (RASMCs). PDGF-BB induced the migration and proliferation of RASMCs that were inhibited by olibanum extract in a dose-dependent manner. The PDGF-BB-increased phosphorylation of p38 mitogen-activated protein kinase (MAPK); the heat shock protein (Hsp) 27 was significantly inhibited by the olibanum extract. The effects of PDGF-BB-induced extracellular signal-regulated kinase1/2 was not altered by the olibanum extract. Treatment with olibanum extract inhibited PDGF-BB-stimulated sprout out growth of aortic rings. These results suggest that the water extract of olibanum inhibits PDGF-BB-stimulated migration and proliferation in RASMCs as well as sprout out growth, which may be mediated by the inhibition of the p38 MAPK and Hsp27 pathways.

Propofol Inhibits Platelet-derived Growth Factor-stimulated Migration in Rat Aortic Smooth Muscle Cells / 대한마취과학회지

BACKGROUND: Propofol is the extensively used general anesthetic-sedative agent.Although propofol is known to be involved in migration of various cells, migration response to it in vascular smooth muscle cells is not investigated. This study was carried out to determine the role of propofol in migration of rat aortic smooth muscle cells (RASMCs). METHODS: A7r5 RASMCs were used.Cell migration was examined by the analysis of 5 ng/ml of platelet-derived growth factor (PDGF)-induced RASMC response after treatment of cells with propofol (1-100micrometer) in the Boyden chamber.The activity of cofilin by propofol in RASMCs was measured by the Western blot analysis for the change of cofilin dephosphorylaton in cells treated with 10micrometer propofol for 5, 10, 15 and 20 min, for the effect of propofol (1, 10 and 100micrometer) on cofilin phosphorylation, and for the effects of ethylene glycol-bis (beta-aminoethyl ether)-N,N,N',N'-tetra acetic acid (2 mM; EGTA), Na3VO4 (200micrometer), and calyculin A (10 nM) on 10micrometer propofol-induced cofilin dephosphorylation. RESULTS: PDGF increased RASMC migration and this response was dose-dependently inhibited by treatment with propofol. Propofol attenuated the cofilin phosphorylation in RASMCs in a dose- and time-dependent manner.Propofol-induced dephosphorylation of cofilin in RASMCs was abolished by calyculin A, a protein phosphatase 2A inhibitor, but not by EGTA, a Ca2+ chelating agent, or Na3VO4, a protein tyrosine phosphatase inhibitor. CONCLUSIONS: The present results suggest that propofol induces the diminution of PDGF-stimulated RASMC migration and this response may be associated with dephosphorylation of cofilin mediated by the protein phosphatase 2A-dependent pathway.

Inhibitory effect of panaxynol on the proliferation of rat aortic smooth muscle cell and its mechanisms / 中国药理学通报

Aim To evaluate the inhibitory effect of panaxynol(PNN) on the proliferation of rat aortic smooth muscle cell(RASMC) and its mechanisms.Methods Cell proliferation was determined using cell count and -TdR incorporation test.Fura-3/AM and confocal were used to measure intracelluar free Ca~(2+) concentration.Expression of mitochondrial transcription factor 1(mtTF1) mRNA was tested by using RT-PR.Results PNN inhibited the RASMC proliferation and DNA synthesis induced by serum and PDGF-BB in a dose-dependent manner.9 ?mol?L~(-1) of PNN inhibited the increase of intracelluar free Ca~(2+) concentration induced by PDGF-BB.PDGF-BB upregulated the expression of mtTF1 mRNA,which could be suppressed by 3,9 ?mol?L~(-1) of PNN significantly.Conclusions PNN can inhibit RASMC proliferation significantly,which might be related to the decrease of intracellular free Ca~(2+) concentration and mtTF1 mRNA expression.

Influence of Total Ginseng Saponin on Contractile Responses of Vasoconstrictors in the Isolated Rat Aorta

BACKGROUND: It has been known that Ginseng extract causes the hypotensive action while it rather produces the hypertensive action. Some studies have suggested that Ginseng extract causes a biphasic response on blood pressure, namely, transient fall followed by prolonged elevation. It has been also shown that administration of Korean Red Ginseng powder has no effect on blood pressure in normotensive and hypertensive rats. The present study was designed to examine the effect of total Ginseng saponin on contractile responses of vasoconstrictors in the rat aorta and to establish the mechanism of its action. METHODS: The ring segment of aorta was mounted in a muscle bath filled with oxygenated Krebs solution for the measurement of isometric tension. After the equilibration period, under the presence of total Ginseng saponin, isometric tension induced by some vasoconstrictors were observed and compared to the control responses. The data were expressed as % of the control tension. RESULTS: Phenylephrine (an adrenergic alpha1-receptor agonist) and high potassium (a membrane depolarizing agent) caused greatly contractile responses in the rat aorta, respectively. However, in the presence of total ginseng saponin (600 g/ml), the contractile responses of phenylephrine (10(-6) and 10(-5) M) and high potassium (3.5 x 10(-2) and 5.6 x 10(-2) M) were markedly potentiated whereas prostglandin F2alpha(5 x 10(-6) M)-induced contractile responses was not affected. The contractile responses induced by phenylephrine (10(-5) M) and high potassium (3.5 x 10(-2) M) even under the presence of total ginseng saponin (600 g/ml) were greatly inhibited by the pretreatment of nicardipine (10(-6) M), a calcium channel blocker. CONCLUSION: Taken together, these experimental results suggest that total ginseng saponin can enhance the contractile responses evoked by stimulation of adrenergic alpha1-receptor and the membrane depolarization in the isolated rat aortic strips, which seems to be associated to calcium influx.

The effect of anti-hypertensive drugs on DNA synthesis and proliferation of ultured rat aortic smooth muscle cells

The aim of this study was to elucidate the effects of anti-hypertensive drugs, nifedipine, furosemide, hydrochlorothiazide, captopril, and atenolol on DNA synthesis and proliferation of cultured rat aortic smooth muscle cells induced by fetal calf serum. Aortic smooth muscle cells from Sprague-Dawley rats were isolated, cultured, and seeded in multi-well plates. When confluent, cells were cultured in a conditioned medium without fetal calf serum. After 72 hours, cells were cultured in the medium retaining 10% fetal calf serum with or without anti-hypertensive drugs by increasing the concentration between 10(-8) and 10(-4) M. DNA synthesis was assessed by [3H]-thymidine uptake and proliferation by cell numbers using a hemocytometer. Nifedipine at a concentration of 10(-5) M and 5 x 10(-5) M inhibited serum-induced DNA synthesis significantly by 50.8% and 86.6%, respectively (p < 0.05). The results of cell numbers paralleled those of 3H-thymidine incorporation. Serum-induced DNA synthesis was also reduced by 32.6% at the highest dose of furosemide (10(-4) M), but there was no statistical significance. Hydrochlorothiazide, captopril, and atenolol did not show anti-proliferative effect throughout any of the doses. In conclusion, among the various anti-hypertensive drugs, nifedipine seems to be most beneficial in view of its direct inhibitory effect on DNA synthesis and proliferation of smooth muscle cells, as well as for its anti-hypertensive effect.

The effect of lovastatin on proliferation of cultured rat mesangial and aortic smooth muscle cells

In order to investigate the anti-proliferative effect of 3-hydroxy-3-methylglutaryl coenzyme. A reductase inhibitor, we evaluated the effects of lovastatin on DNA replication and the proliferation of rat mesangial and aortic smooth muscle cells, both of which were mesenchymal origin cells. Proliferations were determined by measuring [3H]thymidine uptake, and counting the number of cells. Growth-arrested mesangial and aortic smooth muscle cells were exposed to platelet-derived growth factor (PDGF), endothelin (ET) and angiotensin II (Ang II) to stimulate mitogenesis. All agents exhibited dose-dependent stimulation of [3H] thymidine uptake. PDGF was more potent than the others. Ang II increased [3H] thymidine uptake without demonstrable mitogenic activity. Lovastatin inhibited PDGF (10 ng/ml in mesangial cell, 25 ng/ml in smooth muscle cell)-, ET (10(-7)M)- and Ang II (10(-7)M)-induced [3H] thymidine uptake significantly in a dose-dependent manner in both cells. The increase of cell number in response to PDGF and ET treatment were also inhibited at 10 microM of lovastatin. The inhibitory effect of lovastatin was largely overcome in the presence of exogenous mevalonate at 200 microM, with 75.5% restoration from lovastatin-induced inhibition on PDGF-induced [3H] thymidine uptake in mesangial cells (77.8% in aortic smooth muscle cells). However, the addition of cholesterol did not prevent inhibition by lovastatin. In conclusion, lovastatin had an inhibitory effect on mesangial and aortic smooth muscle cell proliferation, and mevalonate was essential for DNA replication in both types of cells. Lovastatin may reduce glomerular and atherosclerotic injury through an anti-proliferative effect on mesangial and vascular smooth muscle cells, in addition to lowering circulating lipids.

Actions of Immature Orange Fruit and Dried Tangerine Peel on the Tension of Isolated Aortic Muscle Strips / 中成药

Objective: To study the effects of immature orange fruit(IOF) and dried tangerine peel(DTP) on the resting tension of isolated aortic muscle strips in rabbits and their mechanisms. Methods: The organ-bath was used to observe the response of aortic strip to IOF and DTP. Results: IOF and DTP dose-dependently increased the tension of aortic strip, and the action of IOF was more significant than that of the same concentration DTP. 10 -7 mol/L phentolamine, 10 -5 mol/L verapamil or incubation with Ca 2+ -free Krebs solution could block the effects of IOF and DTP partly, but 10 -6 mol/L diphenhydramine could not. In endothelium-removed aortic strips, the effects of IOF and DTP decreased after treatment with 10 -7 mol/L atropine. Conclusions: IOF and DTP can contract vascular smooth muscle, which probably contribute to ? adrenergic receptor, cholinergic M receptor on membrane of vascular smooth muscle partly, and is dependent Ca 2+ influx through verapamil-sensitive Ca 2+ channels, but is not related to H 1 histamine receptor.

Experimental study of atherosclerosis ⅣChanges of aortic smooth cell proliferation, platelet free calcium and aggregation in atherosclerotic rabbits and the effects of 8501 on these changes / 中国药理学通报

Smooth muscle cell (SMC) proliferation, platelet free calcium level and aggregation of experimental atherosclerotic rabbits were investigated in this study. Aortic SMC ofhyperlipidemic rabbits in vitro showed higher growth activity than did normal rabbit SMC. And also hyperlipidemic serum stimulated SMC to proliferate at a significantly greater rate than control serum. Moreover, the level of platelet free calcium and the platelet aggregation was also higher in hyperlipidemic rabbits, indicating that activitated platelets possibly release more PDGF to act as a stimulator to SMC proliferation and calcium is an important factor to activate platelets. Furthermore, SMC from 8501-treated rabbits appeared lower proliferative rate than thecells from hyperlipidemic rabbits. And serum from those rabbits inhibited SMC proliferation compared with hyperlipidemic serum, the inhibitory effect was even stronger than that of normal serum. It may be relevant to the favorable effects of 8501 to TXA2/PGI2 balance.

THE STUDY ON TRANSPLANTATION OF THREE-DIMENTIONAL CULTURED ASMC-COLLAGEN GEL TO SUBCUTANEOUS / 解剖学报

Objective To investigate if aortic smooth muscle cells (ASMCs) cultured three-dimentionally with collagen gel can still produce elastic fibers and the acceptance of hosts after transplantated in subcutaneous of rats. Methods AMSC-collagen gels that had been cultured for 2 weeks by three-dimentionally imitating the dermis substitute were transplanted to rats subscutaneous. After 4,7,10,14 and 28 days, the transplantations were examined via HE staining, Gomori aldehyde fuchsin staining, ?-actin immunohistochemistry and elastin immunohistochemistry. Results The amount of elastic fibers increased significantly in the week, whereas on the 28th day, no elastic fibers were detected.There was no remarkable leucocyte infiltration around the ASMC-collagen gel during 28 days.Conclusion Further studies are needed to explore the ASMC-collagen gels as a kind of elastic dermis substitute.

AORTIC SMOOTH MUSCLE CELLS PRODUCED ELASTIC FIBERS IN THREE-DIMENSIONAL CULTURE / 解剖学报

Objective To Study if aortic smooth muscle cells(ASMC) can produce elastic fibers in three-dimensional culture imitating the dermis substitute. Methods Primary culture of ASMCs were obtained by explanting of thoracic aortae from one-week old SD rats. ?-actin immunocytochemistry was used to approve the smooth muscle cells. After subculture, ASMCs were mixed with gels composed of collagen, chitin and glucosaminoglycans, then, three-dimensional culture was carried out. After 1 week and 2 weeks, Gomori aldehyde fuchsin staining and elastin immunocytochemistry were applied to detect the elastic fibers in the ASMC-collagen gels. Results More than 98% of the cultured cells were approved as smooth muscle cells by ?-actin immunocytochemistry. After both 1 and 2 weeks of three-dimentional culture, elastic fibers were detected in the ASMC-collagen gels by both stainings.Conclusion ASMCs can synthesize elastin and produce elastic fiber in three-dimentional culture imitating the dermis substitute.