Dual effect of polyphosphate on mineralization of rat osteoblast ROS17/2.8 cells in a dose-dependent manner

Background: Alpha keto acids are unstable and decompose rapidly. In this study, we tested the ability of alpha keto acids to reduce peroxides and inhibit oxidation of lipoproteins. Methods: Keto salicylic acid (KSA) and Keto Octanoicacid (KoA) were synthesized and their ability to reduce hydrogen peroxides as well as lipid peroxides (LOOH) was measured using 13-hydroperoxyoctadecadienoic acid (13-HPODE). Lipoproteins (LDL and HDL) were isolated from human plasma and oxidation of liporproteins was performed using copper and MPO in the presence or absence of the keto compounds. RAW 264.7 cells and HUVECS were incubated with LPS and mm-LDL respectively either in the presence or absence of the keto compounds. RNA was isolated from treated cells and real time PCR was performed to analyze IL-1α, IL-6, MCP-1 and VCAM1 gene expressions. Reactive oxygen species were evaluated using DCF fluorescence in presence and absence of the keto compounds. Results: KSA reduced both H2O2 and 13-HPODE whereas KoA is able to reduce the former but not the latter. Both compounds inhibited the lipoprotein oxidation in a dose dependent manner and were able to reduce ROS production by H2O2. KSA is able to inhibit both LPS as well as mm-LDL induced inflammation. However, KoA showed a dual effect as it induced inflammatory markers in the presence of LPS, but inhibited the mm-LDL-induced inflammatory gene expressions. Conclusion: The results of our studies suggest that these keto compounds a) inhibit both enzymatic and non enzymatic oxidation of lipoproteins; b) reduce peroxides and ROS and c) have inhibitory and inducing effect on inflammatory cytokine/gene production in presence of mm-LDL and LPS respectively. Based on these results, we predict that these keto compounds could have therapeutic potential in reducing CVD/atherosclerosis-associated inflammation.

Download Full-text

Effect of Hydroxyapatite Nanoparticles of Different Concentrations on Rat Osteoblast

Materials Science Forum ◽

10.4028/www.scientific.net/msf.610-613.1364 ◽

2009 ◽

Vol 610-613 ◽

pp. 1364-1369 ◽

Cited By ~ 9

Author(s):

Zheng Li Xu ◽

Jiao Sun ◽

Chang Sheng Liu ◽

Jie Wei

Keyword(s):

Specific Surface ◽

Surface Area ◽

Specific Surface Area ◽

Control Group ◽

Dependent Manner ◽

Hydroxyapatite Nanoparticles ◽

Inhibition Ratio ◽

Rat Osteoblast ◽

Induced Apoptosis ◽

Dose Dependent

Nano-HAP (10-20nm) were obtained from East China University of Science and Technology. The osteoblasts were primary cultured from rat calvaria and then treated with five different concentrations(20，40，60，80，100µg/ml) of nano-HAP, the osteoblasts without nano-HAP was used as control group. Inhibition ratio, apoptotic rate were evaluated by MTT assay and flow cytometry (FCM), respectively. The specific surface area of nano-HAP was detected by BET. All date were expressed as mean ± standard deviation.Statistical analysis was performed by t test using software SPSS11.0 for Windows. The results indicated that the nano-HAP could inhibit the growth of osteoblasts in a dose-dependent manner. When the concentrations of nano-HAP were 20, 40, 60, 80, 100µg/ml, the inhibition ratio were 2.8%, 22.2%, 26.9%, 38% and 47.7%, and the apoptotic rate were 4.63%, 6.75%, 9.47%, 11.49%, 17.22%, respectively, which were obviously higher than that of control group. The nano-HAP significantly induced apoptosis in osteoblasts. There were the same tendency that the apoptotic and inhibition ratio of osteoblasts were rising with the increasing of the concentration of the nano-HAP. The specific surface area of nano-HAP was 148.140m2/g.

Download Full-text

Dual effects of nitric oxide on cat carotid body chemoreception

Journal of Applied Physiology ◽

10.1152/jappl.2000.89.3.1005 ◽

2000 ◽

Vol 89 (3) ◽

pp. 1005-1012 ◽

Cited By ~ 33

Author(s):

Rodrigo Iturriaga ◽

Sandra Villanueva ◽

Matias Mosqueira

Keyword(s):

Nitric Oxide ◽

Carotid Body ◽

Carotid Sinus ◽

Dependent Manner ◽

Carotid Sinus Nerve ◽

Dual Effect ◽

No Donors ◽

Pentobarbital Sodium ◽

Carbon Fiber Microelectrodes ◽

Dose Dependent

We studied the effects of nitric oxide (NO) released by NO donors on cat carotid body (CB) chemosensory activity during normoxia and hypoxia. CBs excised from pentobarbital sodium-anaesthetized cats were perfused with Tyrode at 38°C and pH 7.40. The frequency of chemosensory discharges (ƒx) was recorded from the carotid sinus nerve, and changes of NO concentration were measured by a chronoamperometric technique, with NO-selective carbon-fiber microelectrodes inserted in the CB. During steady chemosensory excitation induced by hypoxia, bolus injections of NO (ΔNO = 0.5–12 μM), released by S-nitroso- N-acetylpenicillamine (SNAP) and 6-(2-hydroxy-1-methyl-nitrosohydrazino)- N-methyl-1-hexanamine (NOC-9), transiently reduced ƒx in a dose-dependent manner. However, during normoxia, the same concentration of NO (ΔNO = 0.5–13 μM) released by the NO donors increased ƒx in a dose-dependent manner. The present results show a dual effect of NO on CB chemoreception that is dependent on the Po 2 levels. During hypoxia, NO is predominantly an inhibitor of chemoreception, whereas, in normoxia, NO increased ƒx. The mechanisms by which NO produces chemosensory excitation during normoxia remain to be determined.

Download Full-text

Drynaria fortunei-derived total flavonoid fraction and isolated compounds exert oestrogen-like protective effects in bone

British Journal Of Nutrition ◽

10.1017/s0007114512005405 ◽

2013 ◽

Vol 110 (3) ◽

pp. 475-485 ◽

Cited By ~ 33

Author(s):

Ka-Chun Wong ◽

Wai-Yin Pang ◽

Xin-Lun Wang ◽

Sao-Keng Mok ◽

Wan-Ping Lai ◽

...

Keyword(s):

Chinese Herb ◽

Osteoblastic Cell ◽

Dependent Manner ◽

Protective Effects ◽

Receptor Activator ◽

Rat Osteoblast ◽

Flavonoid Fraction ◽

Umr 106 ◽

Dose Dependent ◽

Tomography Analysis

Drynaria fortunei (Kunze) J. Sm. (DF), a Chinese herb commonly used for the treatment of bone fracture, was previously shown to exert anabolic effects on bone. However, its active ingredients as well as the mechanisms of action are far from clear. The present study aimed to characterise the bone anabolic effects of DF flavonoid fraction (DFTF) in ovariectomised (OVX) mice and to determine if DFTF and its isolated compounds exert oestrogen-like effects in rat osteoblast-like UMR-106 cells. Young OVX C57/BL6J mice were treated orally with DFTF (0·087, 0·173 or 0·346 mg/g per d), 17β-oestradiol (2 μg/g per d) or its vehicle for 6 weeks. Serum and urine samples were collected for biochemical marker analysis. Bones were collected for computed tomography analysis. UMR-106 cells were treated with DFTF and isolated compounds naringin, (2S)-5,7,3′,5′-tetrahydroxy-flavonone 7-O-neohesperidoside (compound 1) and 5,7-dihydroxychromone 7-O-neohesperidoside (compound 2). DFTF exerted dose-dependent effects in improving bone mineral densities as well as bone strength at the femur, tibia and lumbar spine L1 in OVX mice. DFTF and the three isolated compounds stimulated osteoblastic cell proliferation and alkaline phosphatase activities in a dose-dependent manner. In addition, they stimulated the ratio of osteoprotegrin and receptor-activator NF-κB ligand mRNA expression, suggesting their involvement in inhibiting osteoclastogenesis. These stimulatory effects on osteoblastic functions were abolished in the presence of oestrogen receptor (ER) antagonist, ICI 182780. The present results suggested that DFTF is effective in protecting against OVX-induced bone loss in mice, and its actions in regulating osteoblastic activities appear to be mediated by ER.

Download Full-text

A colon epithelial protein(s) induces oral tolerance in a dose dependent manner in the trinitrobenzene sulfonic acid (TNBS) model of colitis in rats

Gastroenterology ◽

10.1016/s0016-5085(01)81385-8 ◽

2001 ◽

Vol 120 (5) ◽

pp. A279-A279

Author(s):

A DASGUPTA ◽

J GIRALDO ◽

P AMENTA ◽

K DAS

Keyword(s):

Sulfonic Acid ◽

Oral Tolerance ◽

Protein S ◽

Trinitrobenzene Sulfonic Acid ◽

Dependent Manner ◽

Dose Dependent

Download Full-text

Effects of Low Molecular Weight Heparin and Unfragmented Heparin on Induction of Osteoporosis in Rats

Thrombosis and Haemostasis ◽

10.1055/s-0038-1645074 ◽

1990 ◽

Vol 63 (03) ◽

pp. 505-509 ◽

Cited By ~ 51

Author(s):

Thomas Mätzsch ◽

David Bergqvist ◽

Ulla Hedner ◽

Bo Nilsson ◽

Per Østergaar

Keyword(s):

Molecular Weight ◽

Bone Mineral ◽

Low Molecular Weight Heparin ◽

Zinc Content ◽

Low Molecular Weight ◽

Dependent Manner ◽

Bone Mineral Mass ◽

Bone Ash ◽

Dose Dependent ◽

Mineral Mass

SummaryA comparison between the effect of low molecular weight heparin (LMWH) and unfragmented heparin (UH) on induction of osteoporosis was made in 60 rats treated with either UH (2 IU/ g b w), LMWH in 2 doses (2 Xal U/g or 0.4 Xal U/g) or placebo (saline) for 34 days. Studied variables were: bone mineral mass in femora; fragility of humera; zinc and calcium levels in serum and bone ash and albumin in plasma. A significant reduction in bone mineral mass was found in all heparin-treated rats. There was no difference between UH and LMWH in this respect. The effect was dose-dependent in LMWH-treated animals. The zinc contents in bone ash were decreased in all heparin-treated rats as compared with controls. No recognizable pattern was seen in alterations of zinc or calcium in serum. The fragility of the humera, tested as breaking strength did not differ between treatment groups and controls. In conclusion, if dosed according to similar factor Xa inhibitory activities, LMWH induces osteoporosis to the same extent as UH and in a dose-dependent manner. The zinc content in bone ash was decreased after heparin treatment, irrespective of type of heparin given.

Download Full-text

Effects of NO-Donors on Thrombus Formation and Microcirculation in Cerebral Vessels of the Rat

Thrombosis and Haemostasis ◽

10.1055/s-0038-1650532 ◽

1996 ◽

Vol 76 (01) ◽

pp. 111-117 ◽

Cited By ~ 10

Author(s):

Yasuto Sasaki ◽

Junji Seki ◽

John C Giddings ◽

Junichiro Yamamoto

Keyword(s):

Blood Flow ◽

Thrombus Formation ◽

Dependent Manner ◽

Red Cell ◽

Cell Velocity ◽

Red Cell Velocity ◽

The Mean ◽

Wall Shear ◽

Dose Dependent

SummarySodium nitroprusside (SNP) and 3-morpholinosydnonimine (SIN-1), are known to liberate nitric oxide (NO). In this study the effects of SNP and SIN-1 on thrombus formation in rat cerebral arterioles and venules in vivo were assessed using a helium-neon (He-Ne) laser. SNP infused at doses from 10 Μg/kg/h significantly inhibited thrombus formation in a dose dependent manner. This inhibition of thrombus formation was suppressed by methylene blue. SIN-1 at a dose of 100 Μg/kg/h also demonstrated a significant antithrombotic effect. Moreover, treatment with SNP increased vessel diameter in a dose dependent manner and enhanced the mean red cell velocity measured with a fiber-optic laser-Doppler anemometer microscope (FLDAM). Blood flow, calculated from the mean red cell velocity and vessel diameters was increased significantly during infusion. In contrast, mean wall shear rates in the arterioles and venules were not changed by SNP infusion. The results indicated that SNP and SIN-1 possessed potent antithrombotic activities, whilst SNP increased cerebral blood flow without changing wall shear rate. The findings suggest that the NO released by SNP and SIN-1 may be beneficial for the treatment and protection of cerebral infarction

Download Full-text

Melatonin actions in the heart; more than a hormone

Melatonin Research ◽

10.32794/mr11250002 ◽

2018 ◽

Vol 1 (1) ◽

pp. 21-26 ◽

Cited By ~ 9

Author(s):

Darío Acuña-Castroviejo ◽

Maria T Noguiera-Navarro ◽

Russel J Reiter ◽

Germaine Escames

Keyword(s):

Cell Membranes ◽

Myocardial Cell ◽

Rat Tissues ◽

Dependent Manner ◽

Broad Distribution ◽

Multiple Organs ◽

High Doses ◽

Extrapineal Melatonin ◽

Dose Dependent ◽

Different Doses

Due to the broad distribution of extrapineal melatonin in multiple organs and tissues, we analyzed the presence and subcellular distribution of the indoleamine in the heart of rats. Groups of sham-operated and pinealectomized rats were sacrificed at different times along the day, and the melatonin content in myocardial cell membranes, cytosol, nuclei and mitochondria, were measured. Other groups of control animals were treated with different doses of melatonin to monitor its intracellular distribution. The results show that melatonin levels in the cell membrane, cytosol, nucleus, and mitochondria vary along the day, without showing a circadian rhythm. Pinealectomized animals trend to show higher values than sham-operated rats. Exogenous administration of melatonin yields its accumulation in a dose-dependent manner in all subcellular compartments analyzed, with maximal concentrations found in cell membranes at doses of 200 mg/kg bw melatonin. Interestingly, at dose of 40 mg/kg b.w, maximal concentration of melatonin was reached in the nucleus and mitochondrion. The results confirm previous data in other rat tissues including liver and brain, and support that melatonin is not uniformly distributed in the cell, whereas high doses of melatonin may be required for therapeutic purposes.

Download Full-text

Evaluating the Proposed Mechanism by Which Atorvastatin Can Protect Renal Tissue against Contrast Media: An Animal study

Al Mustansiriyah Journal of Pharmaceutical Sciences ◽

10.32947/ajps.19.01.0395 ◽

2019 ◽

pp. 75-84

Keyword(s):

Contrast Media ◽

Kidney Injury ◽

Saline Group ◽

Pleiotropic Effect ◽

Renal Tissue ◽

Male Rats ◽

Dependent Manner ◽

Group 2 ◽

Dose Dependent ◽

Media Group

Contrast- induced nephropathy (CIN) is an elevation of serum creatinine of ≥ 0.5 mg/dL from baseline after two to three days of exposure to contrast substance if there is no other cause for acute kidney injury. Atorvastatin may protect normal kidney physiology from contrast- induced kidney injury by effects unrelated to hypolipidemia termed pleiotropic effect by decline of endothelin production, angiotensin system down regulation, and under expression of endothelial adhesion molecules. This study was conducted to assess the strategy by which atorvastatin can achieve protective effect for kidneys after exposure to contrast media in an animal model. A 40 male rats were distributed randomly into 4 groups; ten rats for each: group (1): given normal saline; group (2): CIN group given iopromide as contrast media; group (3): given atorvastatin (20mg/kg) and iopromide; and group (4): given atorvastatin (40mg/kg) and iopromide. Blood collected by cardiac puncture for detection of serum glutathione, malondialdehyde, matrix metalloproteinase-9, and interleukin-18. The results have shown a significant increase in inflammatory and oxidative stress markers in contrast media group, and significant reduction in these markers in atorvastatin treated groups, in a dose-dependent manner. As conclusion, atorvastatin mechanism for protection against CIN in a dose-dependent manner can mediate by anti-inflammatory and antioxidant effects.

Download Full-text

Oxygenation of 18-hydroxycorticosterone as the final reaction for aldosterone biosynthesis

Acta Endocrinologica ◽

10.1530/acta.0.1070395 ◽

1984 ◽

Vol 107 (3) ◽

pp. 395-400 ◽

Cited By ~ 9

Author(s):

Itaru Kojima ◽

Etsuro Ogata ◽

Hiroshi Inano ◽

Bun-ichi Tamaoki

Keyword(s):

Carbon Monoxide ◽

Hydroxysteroid Dehydrogenase ◽

Dependent Manner ◽

In Vitro Production ◽

Mitochondrial Preparation ◽

Final Reaction ◽

Vitro Production ◽

Dose Dependent ◽

Cytochrome P 450

Abstract. Incubation of 18-hydroxycorticosterone with the sonicated mitochondrial preparation of bovine adrenal glomerulosa tissue leads to the production of aldosterone, as measured by radioimmunoassay. The in vitro production of aldosterone from 18-hydroxycorticosterone requires both molecular oxygen and NADPH, and is inhibited by carbon monoxide. Cytochrome P-450 inhibitors such as metyrapone, SU 8000. SU 10603, SKF 525A, amphenone B and spironolactone decrease the biosynthesis of aldosterone from 18-hydroxycorticosterone. These results support the conclusion that the final reaction in aldosterone synthesis from 18-hydroxycorticosterone is catalyzed by an oxygenase, but not by 18-hydroxysteroid dehydrogenase. By the same preparation, the production of [3H]aldosterone but not [3H]18-hydroxycorticosterone from [1,2-3H ]corticosterone is decreased in a dose-dependent manner by addition of non-radioactive 18-hydroxycorticosterone.

Download Full-text