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@#AIM: To observe the effects of pyridoxamine(PM)on RAGE, ROS and apoptosis in RPE cells treated with advanced glycation end products(AGEs), and to investigate the protective effect of PM on RPE cells in diabetic retinopathy. <p>METHODS:Primary cultured human RPE cells, the third generation of cells were synchronized with serum-free Dulbecco-modified Eagle medium for 24h, and then grouped: 1)Control group: cultured with 100mg/L BSA for 48h; 2)AGEs-treated group: cultured with 200mg/L AGEs for 48h; 3)PM group: PM1 group: cultured with 16mg/L PM+200mg/L AGEs for 48h; PM2 group: cultured with 32mg/L PM+200mg/L AGEs for 48h. The expression of RAGE protein was detected by immunohistochemistry. The formation of ROS was observed by fluorescence microscopy. The apoptosis of cells was detected by TUNEL. <p>RESULTS:The expression of RAGE protein, ROS and apoptosis of RPE cells in PM group were significantly lower than those in AGEs-treated group, and decreased with the increase of PM concentration. <p>CONCLUSION:Pyridoxamine can inhibit the expression of RAGE and the production of ROS, reduce apoptosis, and have a protective effect on RPE cells.
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Vitamin B6 related epilepsy is a group of epileptic diseases,seizures in which could not be con-trolled by antiepileptic drugs,but could be controlled or obviously improved by vitamin B6 .It comprises of pyridoxine dependent epilepsy and pyridoxine responsive epilepsy predominantly,and the latter includes vitamin B6 responsive in-fantile spasms,pyridox(am)ine -5′-phosphate oxidase (PNPO)deficiency,hyperphosphatasia mental retardation syndrome (Mabry syndrome)and so on.The clinical presentations of the diseases above are nonspecific,manifesting as refractory seizures onset in neonatal or infantile period,which need to be distinguished from other diseases such as new-born hypoxic ischemic encephalopathy,Ohtahara syndrome and non -ketotic hyperglycinemia.Pyridoxine dependent epilepsy,PNPO deficiency and Mabry syndrome have relative specific biomarkers and known disease -causing genes, which are helpful for diagnosis.It is suggested that pyridoxine or pyridoxal phosphate should be tried first for all patients started seizures early (including all infantile spasms patients),avoiding missing these diseases.And once diagnosed,vi-tamin B6 should be maintained long -term or all the life according to the detailed disease.
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Objective: To observe the effect of pyridoxamine and telmisartan on the indexes of myocardial remodeling in spontaneous hypertensive rats (SHR). Methods: A total of 48 male SHR at 22 weeks of age were randomly divided into 4 groups:①Hypertension (H) control group, the rats received distilled water 2 ml/d,②telmisartan (T) group, the rats received telmisartan 6 mg/(kg.d),③pyridoxamine (P) group, the rats received pyridoxamine 200 mg/(kg.d),④Combination (TP) group, the rats received both telmisartan and pyridoxamine. All animals were treated for 16 weeks and the systolic blood pressure (SBP) was measured before and after treatment. After treatment, the serum levels of nitric oxide (NO) and super oxide dismutase (SOD) were examined by chemiluminescent method, advanced glycation end-products (AGEs) was detected by ELISA, left ventricular weight index and collagen volume fraction (CVF) in myocardial tissue were calculated, the mRNA expression of myocardial receptor of advanced glycation end products (RAGE) was evaluated by real time RT-PCR. Results: Compared with H group, SBP levels were decreased in T and TP groups,P0.05. Compared with H group, the serum levels of NO and SOD were increased in T, P and TP groups,P<0.01; while compared with T group and P group, the levels of NO and SOD were further increased in TP group,P<0.05. Compared with H group, left ventricular weight index and CVF were decreased in T, P and TP groups,P<0.01; while compared with T group and P group, left ventricular weight index and CVF were further decreased in TP group,P<0.05. Pyridoxamine and telmisartan had the coordinative effect on left ventricular weight index and CVF, P<0.05. The serum levels of AGEs were lower in T group (5.99 ± 0.51) mg/L, P group (5.57 ± 0.91) mg/L and TP group (5.24 ± 0.63) mg/L than that in H group, (6.71 ± 0.50) mg/L,P<0.01; while compared with T group and P group, AGEs was further decreased in TP group,P<0.05. The mRNA expressions of RAGE were reduced in T group (0.035 ± 0.010), P group (0.036 ± 0.005) and TP group (0.024 ± 0.007) than that in H group (0.053 ± 0.010),P <0.01; while compared with T group and P group, the mRNA of RAGE was further reduced in TP group, P<0.05. Conclusion: Pyridoxamine could improve the oxidative stress and the indexes of myocardial remodeling independently from decreasing blood pressure in SHR. Combined intervention of P and T may break the coordination systems between AGEs-RAGE and renin-angiotensin, therefore further improve the indexes of myocardial remodeling in SHR.
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Objective:To explore influence of monotherapy or combined use of telmisartan and pyridoxamine on aor-tic remodeling in spontaneously hypertensive rats (SHR)and its possible mechanism.Methods:A total of 48 male SHE were randomly and equally divided into hypertension control group,telmisartan group,group,and telmisartan+ group (combined treatment group). Kyoto Wistar rats of the same age and gender were regarded as normal blood pressure control group (normal control group). Thoracic aortic section were examined by related staining af-ter 16 weeks intervention to calculate the ratio of aortic wall thickness to radius of lumen (Tw/Rl),the ratio of wall area to lumen area (W/L),and the area ratio of media elastic fiber/collagen fiber. Concentrations of related en-zymes and receptor etc. of abdominal aortic were measured.Results:Compared with hypertension control group, there was significant rise in ratio of media elastic fiber/collagen fiber area and significant reduction in media collagen fiber/media area ratio in telmisartan group,pyridoxamine monotherapy group and combined treatment group,and there were significant decrease in Tw/Rl [(0.17±0.02)vs. (0.12±0.01)]and W/L [(0.29±0.03)vs. (0.22± 0.02)]ratios in combined treatment group,P <0.05 or <0.01;immunohistochemistry indicated that there were significant reductions in thoracic aortic receptor of advanced glycation end products (RAGE) [(0.24±0.03)vs.(0.17±0.03)]and extracellular signal-regulated kinase 1/2 (p-ERK1/2 )expression [(0.63 ± 0.06)vs. (0.37± 0.04)]in combined treatment group,P <0.05,<0.01. Fluorescence quantitative PCR indicated that medication can significantly reduce nicotinamide adenine dinucleotide phosphate (NADPH)oxidase subunit p47phox mRNA ex-pression (P <0.01 all),especially in combined treatment group (P =0.001).Conclusion:Combined use of telmis-artan and pyridoxamine is superior to the single use of either drug on improving thoracic aortic remodeling in SHR, the mechanism may be related to it reduces local expression of RAGE and p-ERK1/2 ,and inhibits oxidase subunit p47 of NADPH.
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Objective To investigate the effects and the mechanism of telmisartan and pyridoxamine on oxidative stress in spontaneously hypertensive rats(SHR).Methods SHRs(male,20 weeks of age) were randomly divided into four groups (n＝ 12 for each):hypertension control (HC) group (2 ml of distilled water),telmisartan group[T,6 mg/(kg · d)],pyridoxamine group[P,200 mg/(kg · d)]and combined group(TP,6 mg/kg telmisartan and 200 mg/kg pyridoxamine per day).Treatments were continued for 16 weeks.The normal control group included 13 WKY rats and received gastric lavage with distilled water.SBP of tail artery was measured during the intervention ervey 2 weeks.The levels of AGEs,SOD and MDA were measured by ELISA,xanthine oxidase and thiobarbituric acid methods after the intervention.Expressiones of NF-κBp65,ERK1 and ERK2 in renal tissue were detected by immunohistochemistry.Expression of RAGE in the renal cortex was investigated by Western blot.Results SOD activity was decreased in the HC group.The levels of AGEs,MDA,RAGE and the activations of NF-κBp65 and ERK1/2 were increased in the HC group (t＝4.53,5.52,2.93,al1 P＜0.05).After the 16 weeks' intervention,SOD activity was elevated in T,P and TP groups compared to that in HC group (P＜0.05).The positive expressiones of NF-κBp65,ERK1 and ERK2 were significantly reduced in T,P and TP groups compared to those in HC group (F＝20.13、148.82、18.70,all P＜0.05).All the positive expressiones of NF-κBp65,ERK 1and ERK2 were lowest in the TP group versus T and P groups (t ＝ 3.58、2.84,P ＜ 0.05).Conclusions Telmisartan and pyridoxamine can alleviate the oxidative stress in spontaneously hypertensive rats,which may result from the blocking effect of Ang Ⅱ,the reduction of AGEs-RAGE and inhibiting the signal pathways of ROS,NF-κBp65 and ROS-ERK1/2.
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The solution conformations of pyridoxal-5'-phosphate and pyridoxamine- 5'-phosphate have been investigated using Eu(III) as a nuclear magnetic resonance shift probe. Binding of Eu(III) to pyridoxal phosphate results in the formation of two complexes, at the phosphate group and the o-hydroxy-aldehyde moiety, which are in slow exchange on the nuclear magnetic resonance time-scale. The lanthanide-induced pseudo contact shifts calculated using the McConnell-Robertson equation (J. Chem. Soc. (1950), 22, 1561) are in good agreement with the experimentally observed values for both pyridoxal phosphate and pyridoxamine phosphate and lead to a family of closely related conformations.
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A method for the determination of B6-pyridoxamine (PAM), pyridoxal (PAL) and pyridoxine (POL) by RPLC was proposed. The procedure included the addition of 0.1M H2SO4 to the sample, hydrolysis for 30 min at 120℃, centrifuging, filtration and direct analysis by ODS Cl8 column. PAM, PAL and POL were completely separated, when the flow rate of the mobile phase (pH2.0-2.1) was 1.0-1.5ml/min. Quantitation by a fluorescent detector was performed with Exc: 293 nm and Em: 395 nm. The recovery ranged from 99 to 103% with CV 5.0-5.3%. The method was simple, rapid, sensitive and reproducible.