1.The effect of calcium channel blocker on human sperm.
National Journal of Andrology 2003;9(9):700-706
Calcium ion exists extensively in cells as the second messenger, and calcium channel blocker (CCB) is widely used to treat cardiac, skeletal muscular diseases. With the advances in the investigation of human sperm calcium channel, CCB has been proved to affect not only the shape, activation and acrosome reaction, but also the function of human sperm, which may afford a new approach to male contraception.
Calcium Channel Blockers
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pharmacology
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Calcium Channels
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physiology
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Humans
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Male
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Spermatozoa
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drug effects
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physiology
2.Effect of calcium on medium alkalinization induced by salicylic acid in Salvia miltiorrhiza suspension cultures.
Liancheng LIU ; Cong WANG ; Juan'e DONG ; Hui SU ; Zequn ZHUO ; Yaxin XUE
Chinese Journal of Biotechnology 2013;29(7):986-997
We studied medium alkalinization in Salvia miltiorrhiza suspension cultures treated with salicylic acid and the effect of Ca2+ in this process through application of calcium channel antagonists (Verapamil, LaCl3, LiCl, 2-APB) and ionophore A23187. The results show that salicylic acid could induce significant medium alkalinization in S. miltiorrhiza culture. Verapamil and LaCl3 or LiCl and 2-APB, two different groups of calcium channel antagonist, significantly inhibited the medium alkalinization induced by salicylic acid. However, the suppression effect of verapamil or LaCl3 on medium alkalinization induced by salicylic acid was higher than that of LiCl or 2-APB. When two types of calcium channel inhibitor (LaCl3 and 2-APB) were used together, the medium alkalinization induced by salicylic acid was completely suppressed and even reduced the pH in medium. On the other hand, A23187 could promote the medium alkalinization. Based on the results above, we speculated that salicylic acid could induce significant medium alkalinization in S. miltiorrhiza culture, depending on the calcium from both extracell and intracell. Moreover, calcium from extracell plays a more dominant role in this process. Reveal of relationship in this research between Ca2+ and medium alkalinization can provide theory evidence for mechanism of the plant secondary metabolism.
Calcimycin
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pharmacology
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Calcium
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chemistry
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Calcium Channel Blockers
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pharmacology
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Calcium Ionophores
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pharmacology
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Cell Culture Techniques
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Culture Media
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chemistry
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Salicylic Acid
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pharmacology
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Salvia miltiorrhiza
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metabolism
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Verapamil
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pharmacology
3.Effects of isoflurane combined with diltiazem on human sperm motility.
Bo XU ; Xiao-Hai WANG ; Li-Jun WANG ; Hui-Jin SUN
National Journal of Andrology 2008;14(12):1109-1111
OBJECTIVETo observe the effects of isoflurane combined with diltiazem on human sperm motility in vitro and to investigate its possible mechanism.
METHODSTen normal semen samples were collected, each divided into 9 groups, one as the control and the others treated in vitro with different concentrations of diltiazem or diltiazem +4.2% isoflurane for 1 hour. Sperm motility was observed with the computer-assisted sperm analyzer.
RESULTSCompared with the control, diltiazem significantly decreased sperm motility at the concentrations of 0.01 g/L, 0.04 g/L, 0.2 g/L and 1 g/L in a dose-dependent manner, and reduced it to approximately 0% at 1 g/L. When combined with 4.2% isoflurane, diltiazem obviously increased sperm motility at 0.01 g/L, markedly decreased it at 0.2 g/L, and effected no significant difference at 0.04 g/L and 1 g/L as compared with the corresponding concentrations of diltiazem alone.
CONCLUSIONThe stimulating effect of isoflurane on sperm motility may be associated with the calcium ion channel in sperm. When completely blocked by diltiazem, this effect may turn into an inhibition of sperm motility.
Adult ; Calcium Channel Blockers ; pharmacology ; Diltiazem ; pharmacology ; Drug Antagonism ; Humans ; Isoflurane ; pharmacology ; Male ; Sperm Motility ; drug effects
4.High throughput screening method of potassium channel regulators.
Ya-ping PAN ; Xiang-hua XU ; Xiao-liang WANG
Acta Pharmaceutica Sinica 2004;39(2):85-88
AIMTo discover new regulators of potassium channel, an in vitro assay based on DiBAC4 (3) to determine the fluorescence was established for high throughput screening.
METHODSA cell-based 96-well format fluorescence assay using DiBAC4 (3) in cultured PC12 cells was described. Cells were loaded with 5 mumol.L-1 DiBAC4 (3) and incubated at 37 degrees C for 30 min before adding KCl or several known potassium channel regulators. The cellular DiBAC4 (3) fluorescence responce was then detected. The fluorescence changes can be used to evaluate membrane potential changes, which are determined mainly by potassium channels.
RESULTSExtracellular high K(+)-induced depolarization and several potassium channel blockers including 4-AP, TEA, E-4031, glibenclamide, quinidine and nifedipine all evoked increases in DiBAC4 (3) fluorescence response. The potassium channel opener, cromakalim, evoked decrease in DiBAC4 (3) fluorescence response. The fluorescence changes of 4-AP, TEA, glibenclamide, nifedipine and cromakalim were in a concentration-dependent manner. In 76 compounds screened by using the established DiBAC4 (3)-based assay, 9 compounds were found to change the fluorescence dose-dependently. Patch clamp technique is needed to further testify and screen their actions on potassium currents.
CONCLUSIONThe DiBAC4 (3)-based assay is easily operated, economical and repeatable. So, it can be performed by high throughput screening for potassium channel regulators.
4-Aminopyridine ; pharmacology ; Animals ; Barbiturates ; chemistry ; Calcium Channel Blockers ; pharmacology ; Cromakalim ; pharmacology ; Isoxazoles ; chemistry ; Membrane Potentials ; drug effects ; Nifedipine ; pharmacology ; PC12 Cells ; Patch-Clamp Techniques ; Piperidines ; pharmacology ; Potassium Channel Blockers ; pharmacology ; Potassium Channels ; drug effects ; Pyridines ; pharmacology ; Quinidine ; pharmacology ; Rats
5.Pharmacokinetics and tissue distribution of clevidipine and its metabolite in dogs and rats.
Ying ZHOU ; Xiao-meng HE ; Hu-qun LI ; Yang NI ; Ming-zhen XU ; Hui CHEN ; Wei-yong LI
Journal of Huazhong University of Science and Technology (Medical Sciences) 2014;34(6):856-860
The purpose of the current study was to examine the pharmacokinetic profiles and tissue distribution of clevidipine, an ultra-short-acting calcium antagonist in Beagle dogs and Sprague-Dawley rats, respectively. The pharmacokinetics and biodistribution of its primary metabolite H152/81 were also evaluated. Dogs received intravenous infusion of clevidipine at a dose rate of 17 μg/(kg·min), and rats were given intravenous administration of clevidipine at a dose of 5 mg/kg. Dog plasma and rat tissues were collected and assayed by HPLC-MS/MS. It was found that plasma clevidipine quickly reached the steady state concentration. The terminal half-life was short (16.8 min), pointing out a rapid elimination after the end of the infusion. The total clearance was 5 mL/(min·kg). In comparison, plasma concentration of H152/81 was increased more slowly and was significantly higher than that of clevidipine. After intravenous administration, clevidipine was distributed rapidly into all tissues examined, with the highest concentrations found in the brain, heart and liver. Maximal concentrations of clevidipine were found in most tissues at 10 min post-dosing. However, the proportion of clevidipine distributed in all tissues was quite small (0.042‰) compared to the total administration dose. It was suggested that clevidipine was mainly distributed in blood and it transformed to inactive metabolite rapidly.
Animals
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Calcium Channel Blockers
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pharmacokinetics
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pharmacology
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Dogs
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Dose-Response Relationship, Drug
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Organ Specificity
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drug effects
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Pyridines
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pharmacokinetics
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pharmacology
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Rats
6.Hepatic cell apoptosis was triggerred by HBx accumulation and independent on verapamil.
Haiping WANG ; Xiaoping CHEN ; Xiangjun BAI
Journal of Huazhong University of Science and Technology (Medical Sciences) 2004;24(3):281-283
In order to study the roles of HBx and calcium inhibitor verapamil in apoptosis of human normal hepatic cells, L02-off, a pTet-off stably integrated human hepatic cell line was established, in which HBx expression was tightly induced by Doxycycline. The effect of different amounts of HBx and verapamil on apoptosis of human normal hepatic cells was detected. The study showed that apoptosis was triggered by accumulation of intracellular HBx, while verapamil had no effects on the apoptotic process. It was concluded that apoptosis mediated by HBx was dose-dependent but calcium-independent.
Apoptosis
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drug effects
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Calcium
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pharmacology
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Calcium Channel Blockers
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pharmacology
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Cells, Cultured
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Dose-Response Relationship, Drug
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Hepatitis B Antigens
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pharmacology
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Hepatocytes
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cytology
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Humans
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Trans-Activators
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pharmacology
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Verapamil
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pharmacology
7.Hepatic cell apoptosis was triggerred by HBx accumulation and independent on verapamil.
Haiping, WANG ; Xiaoping, CHEN ; Xiangjun, BAI
Journal of Huazhong University of Science and Technology (Medical Sciences) 2004;24(3):281-3
In order to study the roles of HBx and calcium inhibitor verapamil in apoptosis of human normal hepatic cells, L02-off, a pTet-off stably integrated human hepatic cell line was established, in which HBx expression was tightly induced by Doxycycline. The effect of different amounts of HBx and verapamil on apoptosis of human normal hepatic cells was detected. The study showed that apoptosis was triggered by accumulation of intracellular HBx, while verapamil had no effects on the apoptotic process. It was concluded that apoptosis mediated by HBx was dose-dependent but calcium-independent.
Apoptosis/*drug effects
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Calcium/pharmacology
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Calcium Channel Blockers/pharmacology
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Cells, Cultured
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Dose-Response Relationship, Drug
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Hepatitis B Antigens/pharmacology
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Hepatocytes/*cytology
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Trans-Activators/*pharmacology
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Verapamil/*pharmacology
8.Impact of lead on cytotoxicity in NRK cells and interference of calcium antagonist.
Xiao-Ting LU ; Qiu-Ying LI ; Hui-Fen GUO
Chinese Journal of Industrial Hygiene and Occupational Diseases 2009;27(6):358-360
Calcium Channel Blockers
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pharmacology
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Cell Survival
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drug effects
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Drug Antagonism
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Humans
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Kidney
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cytology
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drug effects
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Lead
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toxicity
9.The cytotoxicity of maitotoxin to LLC-PK(1) and its antagonism to calcium channel blocking agents.
Hongying LIU ; Shuangqing PENG ; Yong SHEN ; Weizhong SONG
Chinese Journal of Preventive Medicine 2002;36(1):22-24
OBJECTIVETo study the cytotoxicity of maitotoxin (MTX) and its protective effects on calcium-channel blocking agents, so as to provide the data for control and treatment of MTX poisoning.
METHODSCytotoxicity was measured by MTT detecting system, and cytoplasmic free [Ca(2+)]i was measured by F-4500 fluorometry.
RESULTSIncubation with 8 ng/ml MTX for 3 h reduced the survival ratio of LLC-PK(1) cells. The response was found in a time- and concentration-dependent manner, with significant differences as compared with the control group. The MTX-induced increase in [Ca(2+)]i was inhibited by Verapamil and Nifedipine at 5 x 10(-5) mol/L and 1 x 10(-4) mol/L respectively. Both of them significantly reduced the death of the LLC-PK(1) cells.
CONCLUSIONSCytotoxicity of MTX may be caused by the elevated intracellular [Ca(2+)]i. Calcium-channel blocking agents could protect LLC-PK(1) cells from injury by MTX.
Animals ; Calcium ; metabolism ; Calcium Channel Blockers ; pharmacology ; Drug Antagonism ; LLC-PK1 Cells ; Marine Toxins ; toxicity ; Nifedipine ; pharmacology ; Oxocins ; Swine ; Verapamil ; pharmacology