Albumin-bound kynurenic acid is an appropriate endogenous biomarker for assessment of the renal tubular OATs-MRP4 channel / 药物分析学报

Renal tubular secretion mediated by organic anion transporters(OATs)and the multidrug resistance-associated protein 4(MRP4)is an important means of drug and toxin excretion.Unfortunately,there are no biomarkers to evaluate their function.The aim of this study was to identify and characterize an endogenous biomarker of the renal tubular OATs-MRP4 channel.Twenty-six uremic toxins were selected as candidate compounds,of which kynurenic acid was identified as a potential biomarker by assessing the protein-binding ratio and the uptake in OAT1-,OAT3-,and MRP4-overexpressing cell lines.OAT1/3 and MRP4 mediated the transcellular vectorial transport of kynurenic acid in vitro.Serum kynurenic acid concentration was dramatically increased in rats treated with a rat OAT1/3(rOAT1/3)inhibitor and in rOAT1/3 double knockout(rOAT1/3-/-)rats,and the renal concentrations were markedly elevated by the rat MRP4(rMRP4)inhibitor.Kynurenic acid was not filtered at the glomerulus(99％of albumin binding),and was specifically secreted in renal tubules through the OAT1/3-MRP4 channel with an appropriate affinity(Km)(496.7 μM and 382.2 μM for OAT1 and OAT3,respectively)and renal clearance half-life(ti/2)in vivo(3.7±0.7 h).There is a strong correlation in area under the plasma drug concentration-time curve(AUC0-t)between cefmetazole and kynurenic acid,but not with creatinine,after inhibition of rOATs.In addition,the phase of increased kynurenic acid level is earlier than that of creatinine in acute kidney injury process.These results suggest that albumin-bound kynurenic acid is an appropriate endogenous biomarker for adjusting the dosage of drugs secreted by this channel or predicting kidney injury.

Advances in clinical research on drug-induced acute interstitial nephritis / 中国临床药理学与治疗学

The kidneys are one of the main excretory organs for drugs and when drugs are not excreted effectively, they can accumulate in the kidneys or in the interstitial tubules, leading to drug-induced kidney injury. The tubulointerstitium accounts for 80% of the volume of the kidney and is the primary site of response to various types of renal injury. This article focuses on drug-induced acute interstitial nephritis, highlighting its clinical symptoms, listing common induction drugs, analysing pathological features, and explaining its pathogenesis from the perspective of immune response, with the aim of providing a basic and clinical evidence for subsequent studies.

Study on the Effect and Its Mechanism of Bromophenylcurcumin on Apoptosis ，Migration and Invasion of Cho- langiocarcinoma Cells / 中国药房

OBJECTIVE：To study t he effects of bro mophenylcurcumin（GL63）on the apoptosis ，migration and invasion of human cholangiocarcinoma RBE cells ，and to investigate its mechanism based on JAK/STAT signaling pathway. METHODS ：MTT assay was used to detect the effects of different concentrations of GL 63 [0（blank control ，similarly hereinafter ），1.25，2.5，5，10， 20，40 μ mol/L] on the proliferation of RBE cells after 48 h treatment ；the IC 50 was calculated. The effects of different concentrations of GL 63（0，5，10，20 μmol/L）on colony formation were detected by crystal violet staining after 48 h treatment. Flow cytometry ，Hoechst 33342 staining，cell scratch test and Transwell chamber invasion test were used to detect the effects of different concentrations of GL 63（0，5，10，20 μmol/L）on cell cycle distribution ，apoptosis，migration and invasion ability after 24 h treatment. Western blotting assay was adopted to detect the effects of different concentration of GL 63（0，5，10，20 μmol/L） on the expression of JAK 2/STAT3 signal pathway associated proteins. RESULTS ：The proliferation inhibition rates of RBE cells in different concentrations of GL 63 groups（1.25-40 μmol/L）were significantly increase d，compared with blank control group （P＜ 0.01），and showed a dose-dependent trend ，with IC 50 of （8.46±1.30）μmol/L. Compared with blank control group， 85917439。E-mail：zhaoji-an-88@163.com inhibition rates of RBE cell colony formation were significantly decreased in different concentrations （5，10，20 μmol/L）of GL 63 groups（P＜0.01）. The percentage of RBE cells at G 0/G1 phase increased significantly ，while that at S phase decreased significantly （P＜0.01）. The apoptotic rate increased significantly（P＜0.01），and the nucleus showed dense pyknosis and apoptotic bodies. The rate of cell migration and healing was significantly decreased （P＜0.01），and the number of invasive cells through basement membrane was significantly decreased （P＜ 0.01）. The protein expression of p-JAK 2， p-STAT3， Bcl-2， MMP-2， MMP-9， Pro-caspase-9 and P ro-caspase-3 were down-regulated significantly while the expression of Bax ，Cyt-c，Cleaved-caspase-9 and Cleaved-caspase- 3 were up-regulated significantly（P＜0.01）. CONCLUSIONS ：GL63 may inhibit the proliferation ，migration and invasion of RBE cells and promote its apoptosis by inhibiting JAK 2/STAT3 signal pathway.

Simultaneous determination of repaglinide and pravastatin sodium in rat plasma by LC-ms/MS and its application on pharmacokinetic interactions study / 药学学报

The study aims to establish a method for simultaneous determination of repaglinide and pravastatin sodium in rat plasma by LC-MS/MS and to study its pharmacokinetic interactions. Eighteen male SD rats were divided into repaglinide group, pravastatin sodium group and co-administration group. Blood samples were collected at different times after oral administration. Repaglinide and pravastatin sodium in rat plasma were separated by Agilent HC-C18 with the mobile phase consisting of methanol-0.1% formic acid (80 : 20). Detection and quantification were performed by using ESI-MS. The detector was operated in selected Reaction-monitoring mode at m/z 453.3-->230.1 for repaglinide, m/z 447.2-->327.4 for pravastatin sodium and m/z 285.1-->192.9 for diazepam as the internal standard. The calibration curve obtained was linear (R2>0.99) over the concentration range of 9.77-10,000 ng.mL-1 for repaglinide and 4.88-625 ng.mL-1 for pravastatin sodium. Compared with the single administration group, Cmax and AUC0-6h of repaglinide increased significantly (P<0.05) and tmax of pravastatin sodium prolonged (P<0.05) in co-administration group. The method is found to be simple, sensitive and accurate for determining the concentration of repaglinide and pravastatin sodium in rat plasma. There exists pharmacokinetic interactions in the co-administration of repaglinide and pravastatin sodium.