AIM To investigate the effects of iptakalim hydrochloride(Ipt) on the association and dissociation kinetic processes of [ 3H]glibenclamide(Gli) binding with sulfonylurea receptor(SUR 2B ) of ATP sensitive potassium channel (K ATP ) in vascular smooth muscles derived from Wistar rats,and to compare the properties of Ipt with those of nucleotides. The interactions between Ipt and nucleotides were also determined. METHODS The experiments of the association and dissociation kinetic processes of K ATP blocker[ 3H]Gli binding with endothelium denuded aorta smooth muscles were used. RESRLTS (1)The specific bindings of[ 3H]Gli with SUR 2B were not displaced by Ipt at the concentrations of 10 pmol?L -1 ～ 0 5 mmol?L 1 . Ipt 100 ?mol?L -1 retarded the association kinetic process and accelerated the dissociation kinetic process of [ 3H]Gli binding with SUR 2B . (2)Opposite to Ipt, ATP 1 mmol?L -1 accelerated the association kinetic process and retarded the dissociation kinetic process of [ 3H]Gli binding with SUR 2B There was an interaction between ATP and Ipt in the modulation of [ 3H]Gli binding with SUR 2B . (3) Similar with Ipt, ADP 1 mmol?L -1 retarded the association kinetic process and accelerated the dissociation kinetic process of [ 3H]Gli binding with SUR 2B , there was an interaction between ADP and Ipt in the modulation of [ 3H]Gli binding with SUR 2B . (4)Different from ATP and ADP, UDP had no effect on the association and dissociation kinetic process of [ 3H]Gli binding with SUR 2B . And there was not interaction between UDP and Ipt. CONCLUSION Ipt had no affinity with the binding sites of K ATP blocker in SUR 2B , but had negative allosterical modulation on it. The modulatory properties of Ipt were opposite to those of ATP, similar with those of ADP and different from those of UDP. There were interactions between ATP, ADP and Ipt in the modulation of [ 3H]Gli binding with SUR 2B , but there was not interaction between UDP and Ipt.

AIM To study the experimental therapeutic effects of iptakalim hydrochloride(Ipt) on hypertensive cardiac remodeling in spontaneously hypertensive rats(SHR) and stroke prone spontaneously hypertensive rats(SHRsp). METHODS SHR at the age of 12 week old were treated ig with lisinopril 12 mg?kg -1 ?d -1 or Ipt 3 mg?kg -1 ?d -1 , once a day for 30 days. Age matched Wistar rats were used as normal control. 10 week old SHRsp were treated ig with Ipt 0 25,1 0 and 4 0 mg?kg -1 , once a day for 12 weeks. Age matched Wistar rats were used as normal control. After killing animals, the effects of Ipt on hypertensive cardiac remodeling were investigated. RESULTS During the 4 week experimental period, the systolic blood pressure(SBP) and heart rates(HR) of the untreated SHR were increased progressively. Ipt 3 mg?kg -1 ?d -1 could decrease SBP effectively and inhibit the increasing tendency of HR. Ipt had no effects on hypertensive cardiac remodeling in SHR. Under the same experimental conditions, lisinopril 12 mg?kg -1 ?d -1 could decrease SBP effe-ctively and had no effects on HR. The hypertensive cardiac remodeling could be alleviated by lisinopril. During the 12 week experimental period, the SBP of the untreated SHRsp were increased progressively. Ipt 0 25,1 0 and 4 0 mg?kg -1 could decrease the SBP of SHRsp effectively. Ipt at the doses of 0 25 and 1 0 mg?kg -1 had no effects on heart rates. But in the 4th week after administration of Ipt 4 0 mg?kg -1 , significant decrease in heart rates was observed. Compared with Wistar rats, the weight of left ventricle and septum(LV+S) and the ratio of LV+S to body weight(LV+S/BW) in untreated SHRsp were elevated significantly. Ipt 0 25, 1 0 and 4 0 mg?kg -1 ?d -1 could decrease LV+S and LV+S/BW significantly. CONCLUSION Ipt could decrease SBP of SHR and SHRsp effectively. The effects of Ipt on hypertensive cardiac remodeling were related with the experimental therapeutic period. After having been treated with Ipt for 4 weeks, the hypertensive cardiac remodeling could not be reversed. But after having been treated with Ipt for 12 weeks, the hypertensive cardiac remodeling could be reversed significantly.

AIM: To investigate the changes of hemodynamic parameters and ECG in circulatory failure rats induced by organophosphate insecticides DDV and parathion.METHODS: Healthy Wistar male rats,weighing(320?20)g,were treated with organophosphate insecticides by ip.to induce circulatory failure.When the mean blood pressure(MBP) decreased to 45 mmHg,the changes of hemodynamic parameters and ECG were observed.RESULTS: In circulatory failure rats,SBP,DBP,MBP,HR,LVDP,IP,+dp/dtmax,-dp/dtmax,Vpm and +dp/dtmax/IP changed dramatically(P

Aim To investigate the effect of iptakalim on neonatal cardiomyocytes hypertrophy induced by isoprenaline(ISO).Methods Hypertrophy in neonatal rat cardiac myocytes was established via culture with ISO.Total protein content was measured by Lowrys method.The fluorescence intensity of intracellular Ca2+ was detected respectively with Fluo-3/AM loading by the laser confocal microscopy.Results ① 1?10-5mol?L-1 ISO can activated ?-AR completely;② the total protein of cardiomyocytes and intracellular i was markedly decreased by treatment with IPT and represented a dose-dependent manner.Conclusion IPT could inhibit the increase of protein content of cardiomyocytes induced by ISO,which may be contributed to the decease of intracellular Ca2+ concentration.

Idiosyncratic adverse drug reactions (IDR) induce severe medical complications or even death in patients. Alert structure in drugs can be metabolized as reactive metabolite (RM) in the bodies, which is one of the major factors to induce IDR. Structure modification and avoidance of alert structure in the drug candidates is an efficient method for reducing toxicity risks in drug design. This review briefly summarized the recent development of the methodologies for structure optimization strategy to reduce the toxicity risks of drug candidates. These methods include blocking metabolic site, altering metabolic pathway, reducing activity, bioisosterism, and prodrug.
Binding Sites ; Cytochrome P-450 Enzyme System ; metabolism ; Drug Design ; Drug Discovery ; methods ; Drug Recalls ; Drug-Related Side Effects and Adverse Reactions ; prevention & control ; Humans ; Structure-Activity Relationship

Objective To investigate the optimum target plasma concentration of propofol in preventing the adverse effects of carboprost tromethamine in the patients undergoing caesarean section.Methods One hundred and twenty-eight nulliparous parturients who were at full term with a singleton fetus,of American Society of Anesthesiologists physical status Ⅰ or Ⅱ,aged 24-37 yr,weighing 54-78kg,scheduled for elective caesarean section under combined spinal-epidural anesthesia,were randomly divided into 4 groups (n =32 each) using a random number table:control group (group C),and different concentrations of propofol groups (P1-3 groups).Carboprost tromethamine 250 μg was injected into the body of the uterus,and propofol with the target plasma concentrations of 0.8,1.2 and 1.6 μg/ml was simultaneously given by target-controlled infusion in P1,P2 and P3 groups,respectively,and normal saline was infused at a rate of 0.5 ml · kg-1 · h-1 in group C.The occurrence of cardiovascular events was recorded from the end of carboprost tromethamine administration until the end of surgery.The relatedadverse effects after carboprost tromethamine administration,and Ramsay sedation score at 15 mm after carboprost tromethamine administration were recorded,and satisfactory sedation was defined as Ramsay sedation score of 2.The occurrence of complications associated with combined spinal-epidural anesthesia was recorded during the postoperative follow-up.Results Compared with group C,the incidence of carboprost tromethamine-related adverse effects was significantly decreased in P2 and P3 groups,the rate of satisfactory sedation was significantly increased in P1 and P2 groups,the incidence of hypotension and tachycardia was significantly decreased in group P1 (P＜0.05),and no significant change was found in the incidence of carboprost tromethamine-related adv erse effects in group P1,and in the rate of satisfactory sedation in group P3 (P＞ 0.05).Compared with group P1,the incidence of carboprost tromethaminerelated adverse effects was significantly decreased in P2 and P3 groups,the rate of satisfactory sedation was significantly increased in group P2,and the rate of satisfactory sedation was significantly decreased in group P3 (P＜0.05).Compared with group P2,the rate of satisfactory sedation was significantly decreased (P＜0.05),and no significant change was found in the incidence of carboprost tromethamine-related adverse effects in group P3 (P＞0.05).No cardiovascular events were found in group P2,and the incidence of hypotension was 9％ in group P3.Conclusion The optimum target plasma concentration of propofol in preventing the adverse effects of carboprost tromethamine is 1.2 μg/ml in the patients undergoing caesarean section.

AIM To investigate the effects of iptakalim hydrochloride(Ipt) on potassium currents in cardiomyocytes derived from guinea pig and on the specific binding of glibenclamide (Gli) with sulfonylurea receptor(SUR_ 2A ) of ATP-sensitive potassium channel (K_ ATP ) in cardiac membranes derived from Wistar rats. The effects of Ipt on the association and dissociation kinetic processes of Gli binding with SUR_ 2A of K_ ATP in cardiac preparations were also determined. METHODS The effects of Ipt on potassium currents in cardiomyocytes were observed by using patch clamp technique(whole cell recording) after application of the drug in the bath. The experiments of the ass ociation and dissociation kinetic processes of K_ ATP blocker [ 3H]Gli binding with cardiac membranes were used. RESULTS (1)The potassium current-voltage curves (I-U curves) of cardiomyocytes derived from guinea pig were upward shifted by Ipt at the concentrations of 1 and 100 ?mol?L -1 . Within 5 minutes after application of the drug, the current amplitude increased to 124.9%?9.5%(n=5)and 151.6%?11.2%(n=7)of initial current amplitude respectively(P

Aim To investigate the effects of new derivatives of 1H-isoindole-1,3(2H)-dione on angiogenesis in chick chorioallantoic membranes(CAM). Methods The blood vessels of CAM were calculated to determine the antiangiogenic effects of different new compounds. Results Among the 18 new derivatives of 1H-isoindole-1,3(2H)-dione , compound 1,2,3,4,11 and 13 showed significant inhibition on angiogenesis of CAM.Conculsion The 6 new derivatives of 1H-isoindole-1,3(2H)-dione screened out in this experiment may be novel angiogenesis inhibitors.

AIM: To observe the effects of sapindoside on blood pressure,AngⅡ,Ald,ET in the blood plasma and NO in the serum in primary hypertension rat. METHODS: The primary hypertension rats were divided into 5 groups(high,middle and low sapindoside group,control group and captopril group,10 each) in a random fashion and drugs had been given by ig.for 32 days.The blood pressure was messured in the 1,3,7,32 day after administration.At the end of the 32 nd days,AngⅡ,Ald,ET in the blood plasma and NO in the serum were measured. RESULTS: Sapindoside could significantly lower the blood pressure,increase the levels of NO in serum,reduce the concentration of AngⅡ,Ald,ET in the blood plasma. CONCLUSION: Sapindoside plays an important role in decreasing the blood pressure of primary hypertension rat.

Background Vancomycin has been increasingly recommended for the management of endophthalmitis,but few research report has been published about the pharmacokinetics of intravitreal vancomycin up to now.It is necessary to have an exact method to measure the concentration of vancomyein in animal eyes after intravitreal injection.Objective This study was to observe and compare the phamacokinetical process of vancomycin in serum,vitreous and aqueous humor between normal and infected rabbit eyes.Methods Seventy-two healthy adult rabbits were randomly divided into normal group and infected group and 36 rabbits for each.The animal models of endophthalmitis were established by intravitreal inoculation of 2000 CFU/ml staphylococcus aureus in the right eyes of rabbits in the infected group.Once endophthalmitis developed,0.1 ml vancomycin ( 10 g/L) solution was injected into the vitreous of every rabbit.The peripheral blood,vitreous and aqueous humor samples were respectively collected in 4 rabbits for each group at 0.5,2,4,6,12,24,48,72 and 84 hours after injection for detection of vancomycin concentration by high performance liquid chromatography(HPLC-UV).3p97 software was used to create fit parameters of pharmacokinetics.This experiment followed the Regulations for the Administration of Affair Concerning Experimental Animals by State Science and Technology Commission (Version 1988).Results The accuracy of HPLC fitted the detecting request of biological specimen.The concentration-time data of vancomycin in normal rabbit aqueous humor and vitreous was subject to two-compartment model.The pharmacokinetic parameters were separately as following:Cmax was 50.16 mg/L and 751.42 mg/L,t1/2was 51.04 hours and 53.21 hours.The concentration-time data of vancomycin in infected rabbit aqueous humor and vitreous was subject to one-compartment model.The pharmacokinetic parameters were separately as following:Cmaxwas 24.94 mg/L and 687.66 mg/L,t1/2was 11.42 hours and 12.91 hours.The concentration of vancomycin in serum was much lower and almost undectable.The concentration of vancomycin in vitreous was gradually reduced as the prolong of time after injection in both normal group and infected group,but a obvious decline after increased level was scen in aqueous humor.Compared with normal group,the concentrations of vancomycin in both vitreous and aqueous humor were reduced at various time points(P＜0.05,P＜0.01 ).Conclusions HPLC is simple,highly sensitive and specific for the pharmacokinetic analysis of vancomycon.These results indicate that pharmacokinetic parameters of vancomycin alter in pathological condition,which is helpful for us to establish the better treatment guidelines for endophthalmitis.