Hypertension is one of the well-established risk factor for cardiovascular diseases. Calcium channel blockers（CCBs）, chemicals that could block voltage-gated calcium channels（VGCCs） in cardiac muscle and blood ves...Hypertension is one of the well-established risk factor for cardiovascular diseases. Calcium channel blockers（CCBs）, chemicals that could block voltage-gated calcium channels（VGCCs） in cardiac muscle and blood vessels, has been widely used for the treatment of hypertension. Isradipine, a second-generation CCB with high affinity for voltage-operated calcium channels, has not been marked in China. The purpose of this study was to investigate the efficacy, safety and tolerability of isradipine in a phase I clinical trial including 31 healthy Chinese subjects. All subjects received different doses of isradipine at 2.5, 5.0 and 10.0 mg in single-dose study. When the test is completed, subjects treated with 5.0 mg isradipine stayed at the research center for multiple-dose study（5.0 mg isradipine twice daily for 9 d）. Systolic blood pressure（SBP） and diastolic blood pressure（DBP） were measured pre-dose and post-dose（1, 2, 4, 6, 8, 12, 24, 36 and 48 h after isradipine treatment）. Electrocardiography（ECG） and peripheral edema were monitored pre-dose and 4, 8, 24 and 48 h after isradipine treatment. SBP and DBP in single-dose study decreased after isradipine treatment. SBP reached the lowest values 8 h after dosing with a decrease of（7.0±9.7） mmHg（5.4%, P = 0.111） in 2.5 mg group,（7.0±6.9） mmHg（6.0%, P = 0.008） in 5.0 mg group, and（14.0±10.5） mmHg（12.7%, P = 0.005） for 10.0 mg group respectively. Similarly, DBP also reached the lowest values 8 h after dosing with a decrease of（10.0±7.9） mmHg（12.8%, P = 0.004） in 2.5 mg group,（6.0±7.0） mmHg（8.6%, P = 0.003） in 5.0 mg group, and（11.0±4.1） mmHg（15.1%, P = 0.000） in 10.0 mg group respectively. No significant changes of SBP and DBP were observed in multiple-dose study. We detected mild adverse events（AEs）, such as increased transaminase and headache that resolved rapidly and spontaneously without intervention. No serious or potentially life-threatening AE was detected. Our results indicate that isradipin has a good safety and tolerability in Chinese healthy subjects. Long-term study with larger sample size is needed to confirm our conclusion.展开更多
A simple,sensitive and specific ultra performance liquid chromatographyetandem mass spectrometry(UPLCeMS/MS)method was developed for the analysis of isradipine in dog plasma.After extracted with organic solvent,dog pl...A simple,sensitive and specific ultra performance liquid chromatographyetandem mass spectrometry(UPLCeMS/MS)method was developed for the analysis of isradipine in dog plasma.After extracted with organic solvent,dog plasma samples were analyzed on an Acquity UPLC BEH C18 column interfaced with a triple quadrupole tandem mass spectrometer in positive electrospray ionization mode.Acetonitrile:water:formic acid(80:20:0.3,v/v/v)was used as the mobile phase at a flow rate of 0.2 ml/min.The chromatographic run time of each sample was 1.4 min.The calibration curve in plasma was linear in the range of 0.1e40.0 ng/ml.The intra-and inter-day precision was within 13.5%in terms of relative standard deviation(RSD%)and the accuracy was required to be 96.5%e98.4%.The validated UPLCeMS/MS method was successfully applied in a pharmacokinetic study of controlledrelease isradipine in dogs.展开更多
In the present study,we investigated the mechanisms underlying the mediation of iron transport by Ltype Ca^2+ channels(LTCCs)in primary cultured ventral mesencephalon(VM)neurons from rats.We found that cotreatment wit...In the present study,we investigated the mechanisms underlying the mediation of iron transport by Ltype Ca^2+ channels(LTCCs)in primary cultured ventral mesencephalon(VM)neurons from rats.We found that cotreatment with 100 lmol/L FeSO4 and MPP^+(1-methyl-4-phenylpyridinium)significantly increased the production of intracellular reactive oxygen species,decreased the mitochondrial transmembrane potential and increased the caspase-3 activation compared to MPP^+ treatment alone.Co-treatment with 500 lmol/L CaCl2 further aggravated the FeSO4-induced neurotoxicity in MPP^+-treated VM neurons.Co-treatment with 10 lmol/L isradipine,an LTCC blocker,alleviated the neurotoxicity induced by co-application of FeSO4 and FeSO4/CaCl2.Further studies indicated that MPP^+treatment accelerated the iron influx into VM neurons.In addition,FeSO4 treatment significantly increased the intracellular Ca^2+ concentration.These effects were blocked by isradipine.These results suggest that elevated extracellular Ca^2+ aggravates ironinduced neurotoxicity.LTCCs mediate iron transport in dopaminergic neurons and this,in turn,results in elevated intracellular Ca^2+ and further aggravates iron-induced neurotoxicity.展开更多
文摘Hypertension is one of the well-established risk factor for cardiovascular diseases. Calcium channel blockers（CCBs）, chemicals that could block voltage-gated calcium channels（VGCCs） in cardiac muscle and blood vessels, has been widely used for the treatment of hypertension. Isradipine, a second-generation CCB with high affinity for voltage-operated calcium channels, has not been marked in China. The purpose of this study was to investigate the efficacy, safety and tolerability of isradipine in a phase I clinical trial including 31 healthy Chinese subjects. All subjects received different doses of isradipine at 2.5, 5.0 and 10.0 mg in single-dose study. When the test is completed, subjects treated with 5.0 mg isradipine stayed at the research center for multiple-dose study（5.0 mg isradipine twice daily for 9 d）. Systolic blood pressure（SBP） and diastolic blood pressure（DBP） were measured pre-dose and post-dose（1, 2, 4, 6, 8, 12, 24, 36 and 48 h after isradipine treatment）. Electrocardiography（ECG） and peripheral edema were monitored pre-dose and 4, 8, 24 and 48 h after isradipine treatment. SBP and DBP in single-dose study decreased after isradipine treatment. SBP reached the lowest values 8 h after dosing with a decrease of（7.0±9.7） mmHg（5.4%, P = 0.111） in 2.5 mg group,（7.0±6.9） mmHg（6.0%, P = 0.008） in 5.0 mg group, and（14.0±10.5） mmHg（12.7%, P = 0.005） for 10.0 mg group respectively. Similarly, DBP also reached the lowest values 8 h after dosing with a decrease of（10.0±7.9） mmHg（12.8%, P = 0.004） in 2.5 mg group,（6.0±7.0） mmHg（8.6%, P = 0.003） in 5.0 mg group, and（11.0±4.1） mmHg（15.1%, P = 0.000） in 10.0 mg group respectively. No significant changes of SBP and DBP were observed in multiple-dose study. We detected mild adverse events（AEs）, such as increased transaminase and headache that resolved rapidly and spontaneously without intervention. No serious or potentially life-threatening AE was detected. Our results indicate that isradipin has a good safety and tolerability in Chinese healthy subjects. Long-term study with larger sample size is needed to confirm our conclusion.
文摘A simple,sensitive and specific ultra performance liquid chromatographyetandem mass spectrometry(UPLCeMS/MS)method was developed for the analysis of isradipine in dog plasma.After extracted with organic solvent,dog plasma samples were analyzed on an Acquity UPLC BEH C18 column interfaced with a triple quadrupole tandem mass spectrometer in positive electrospray ionization mode.Acetonitrile:water:formic acid(80:20:0.3,v/v/v)was used as the mobile phase at a flow rate of 0.2 ml/min.The chromatographic run time of each sample was 1.4 min.The calibration curve in plasma was linear in the range of 0.1e40.0 ng/ml.The intra-and inter-day precision was within 13.5%in terms of relative standard deviation(RSD%)and the accuracy was required to be 96.5%e98.4%.The validated UPLCeMS/MS method was successfully applied in a pharmacokinetic study of controlledrelease isradipine in dogs.
基金supported by grants from the National Natural Science Foundation of China(81671249)the Natural Science Foundation of Shandong Province,China(ZR2016CM04).
文摘In the present study,we investigated the mechanisms underlying the mediation of iron transport by Ltype Ca^2+ channels(LTCCs)in primary cultured ventral mesencephalon(VM)neurons from rats.We found that cotreatment with 100 lmol/L FeSO4 and MPP^+(1-methyl-4-phenylpyridinium)significantly increased the production of intracellular reactive oxygen species,decreased the mitochondrial transmembrane potential and increased the caspase-3 activation compared to MPP^+ treatment alone.Co-treatment with 500 lmol/L CaCl2 further aggravated the FeSO4-induced neurotoxicity in MPP^+-treated VM neurons.Co-treatment with 10 lmol/L isradipine,an LTCC blocker,alleviated the neurotoxicity induced by co-application of FeSO4 and FeSO4/CaCl2.Further studies indicated that MPP^+treatment accelerated the iron influx into VM neurons.In addition,FeSO4 treatment significantly increased the intracellular Ca^2+ concentration.These effects were blocked by isradipine.These results suggest that elevated extracellular Ca^2+ aggravates ironinduced neurotoxicity.LTCCs mediate iron transport in dopaminergic neurons and this,in turn,results in elevated intracellular Ca^2+ and further aggravates iron-induced neurotoxicity.
