酮色林对体外活化的淋巴细胞细胞因子分泌的影响

目的 研究酮色林(Ketanserin,KT)对活化的淋巴细胞细胞因子分泌的调节.方法 用双抗体夹心ELASA法检测KT对脂多糖(LPS)激活的体外培养的人外周血淋巴细胞细胞因子IL-2、TNF-α、IL-10和TGF-β1分泌的影响.结果 KT浓度依赖性抑制LPS激活的人淋巴细胞致炎因子IL-2的分泌,100 μm ol/L 的KT也可抑制致炎因子TNF-α分泌,而10和100 μmol/L KT可分别浓度依赖性的提高 LPS激活的淋巴细胞分泌抗炎因子IL-10的产量,只有1 00 μmol/L KT 可显著提高LPS激活的淋巴细胞分泌抗炎因子TGF-β1.结论 KT可对体外活化的淋巴细胞细胞因子分泌进行受体非依赖性的直接调节.     

替米沙坦对电压依赖性的Kv1.3和Kv1.5通道电流阻断作用的实验研究

目的 通过观察替米沙坦对电压依赖性的Kv1.3和Kv1.5的阻断作用,探讨替米沙坦对此类通道的阻断可能具有的临床作用.方法 使用双电极电压钳技术记录表达于非洲爪蟾卵母细胞的Kv1.3和Kv1.5钾通道电流,不同浓度灌流观察其对电流影响.结果 (1)替米沙坦浓度依赖性的阻断Kv1.3通道,其阻断的IC50是2.05 μmol/L.替米沙坦对Kv1.3电流的阻断具有电压依赖性.(2)替米沙坦浓度依赖件的阻断Kv1.5通道,其阻断的IC50是2.37 μmol/L.替米沙坦对Kv1.5电流的阻断具有更显著的电压依赖性.结论 替米沙坦阻断开放状态的Kv1.3可能是其发挥免疫调节和抗动脉粥样硬化作用的机制之一.替米沙坦对开放状态的Kv1.5钾通道的阻断可能是其减少心房颤动发生率的作用机制之一.     

阿司咪唑阻断HERG通道的生物学特性及分子机制

目的 观察阿司咪唑对野生型和Y652突变型HERG通道阻断的生物物理学特性,探讨HERG通道分子位点改变对阻断的影响.方法 将HERG通道表达于非洲爪蟾卵母细胞,利用双电极电压钳技术测量其电流,观察阿司咪唑不同浓度、不同电压、不同作用时间下,对野生型和Y652A、Y652R突变型HERG通道电流的阻断作用.结果 阿司咪唑以电压、浓度、时间依赖性阻断HERG通道电流;与野生型比较,Y652A和Y652R突变型可显著减弱阿司咪唑对HERG通道的阻断作用.结论 阿司咪唑优先阻断开放状态的HERG通道,Y652是阿司咪唑与通道结合的关键位点,其极性和侧链长度改变可影响阿司咪唑与通道结合.     

酮色林对表达在卵母细胞上的Kv1.3通道的抑制作用

目的:研究酮色林(KT)对表达在卵母细胞上的Kv1.3通道的作用,探讨其作为心血管药物的潜在免疫效应。方法:在非洲爪蟾卵母细胞表达Kv1.3cRNA通道基因,使用双电极电压钳技术记录通道电流,并用药物干预。结果:KT对Kv1.3通道产生浓度依赖性和可逆性抑制效应,其抑制钾通道50%时的浓度(IC50)为(14.3±1.4)μmol/L。在10μmol/L浓度下,KT降低Kv1.3电流幅值达(43.1±3.2)%;在20μmol/L时降低达(54.1±3.2)%。KT的主要效应是降低电流幅度,对激活曲线和失活曲线无显著影响。对稳态激活曲线,在对照条件下,50%最大激活时的膜电位(V1/2)和曲线斜率(k)分别是(-23.8±0.4)mV和(7.2±0.3);应用10μmol/LKT后,V1/2和k分别是(-22.6±0.5)mV和(8.0±0.4);应用20μmol/LKT后,V1/2和k分别是(-22.3±0.5)mV和(8.1±0.5)。对失活曲线,在对照条件下,V1/2和k分别是(-46.7±0.7)mV和(9.0±0.6);应用10μmol/LKT后,V1/2和k分别是(-48.4±0.7)mV和(8.9±0.7);应用20μmol/LKT后,V1/2和k分别是(-49.2±0.6)mV和(8.8±0.5)。结论:KT在临床相关浓度内,对表达在卵母细胞上的Kv1.3通道有显著的抑制作用。其可能通过抑制淋巴细胞Kv1.3通道,从而抑制淋巴细胞的激活,而在心血管疾病的治疗中有潜在的免疫调节作用。     

Kvβ1.3亚基显著影响DPO-1对表达在卵母细胞上的Kvl.5通道的阻断作用

目的:研究Kvβ1.3亚基和Kv1.5共表达时,对表达在非洲爪蟾卵母细胞的Kv1.5通道DPO-1的阻断作用的影响。方法:在非洲爪蟾卵母细胞上异源表达克隆Kv1.5及Kvβ1.3通道基因,用双电极电压钳技术记录全细胞电流,检测药物对Kv1.5通道及Kv1.5+Kvβ1.3共表达通道电流的影响。结果:DPO-1以电压、频率及浓度依赖方式抑制Kv1.5+Kvβ1.3共表达通道的电流。Kvβ1.3亚基存在时,DPO-1的阻断效应明显减弱,DPO-1阻断的IC50由(0.77士0.12)μmol/L显著增加至(47.21士5.18)μmol/L,增加了约60倍(P<0.01)。结论:Kvβ1.3亚基显著抑制DPO-1对表达在卵母细胞上的Kv1.5通道的阻断作用,但不改变其电压、频率及浓度依赖性,可能机制是Kvβ1.3亚基与DPO-1相互竞争Kv1.5孔区内部的某些结合位点。     

Effect of Matrine on Human Ether à go-go Related Gene (HERG) Channels Expressed in Chinese Hamster Ovary Cells

Objective: To observe the effect of matrine on human ether à go-go related gene (HERG) potassium channels expressed in Chinese hamster ovary (CHO) cells and investigate whether HERG channel is a new target of the pharmacological effect of matrine on arrhythmia and tumor. Methods: HERG channel potassium current in CHO cell was recorded using whole-cell patch-clamp technique, and the influence of matrine on the current was explored. Results: Matrine inhibited HERG potassium current in a dose-dependent manner, and the 50% inhibitory concentration (IC50) was 411±23 μmol/L. Matrine had no significant effect on the activation kinetics, and mainly blocked HERG channels in their closed state. Conclusions: The blocking effect of matrine on HERG channels might be one of the mechanisms against arrythmias and tumors. Unlike most other blockers exerting blocking effect at the intracellular sites by entering the cell with the opening of HERG channel, matrine blocked HERG channels at the extracellular sites.     

乙氧异黄酮二酸钠对豚鼠单个心室肌细胞钙电流的影响

应用全细胞膜片钳技术，研究乙氧异黄酮二酸钠（ｅｔｈｏｘｙ－ｉｓｏｆｌａｖｏｎｅ２－ｃａｒｂｏｘｙｌｉｃａｃｉｄ，ＥＩＣＡ）对豚鼠心室肌细胞上慢钙电流（Ｉｃａ）的影响。结果发现ＥＩＣＡ能使心室肌细胞Ｉｃａ呈剂量依赖性降低，阈浓度为１０－８ｍｏｌ／Ｌ，最大有效浓度为３×１０－５ｍｏｌ／Ｌ；１０－６ｍｏｌ／ＬＥＩＣＡ可明显阻断异丙肾上腺素（Ｉｓｏｐｒｅｎａｌｉｎｅ，Ｉｓｏ）和钙通道激动剂ＢａｙＫ８６４４所致的Ｉｃａ增加（Ｐ＜０．０１）。ＥＩＣＡ能增加外向电流（Ｌｏｕｔ），并被四乙基胺（Ｔｅｔｒａｅｔｈｙｌａｍｍｏｎｉｕｍ，ＴＥＡ，１０－６ｍｏｌ／Ｌ）所拮抗。结果提示：ＥＩＣＡ的降压、减慢心率、抗心律失常作用机制主要与阻断Ｃａ２＋通道（Ｌ型）有关。     

Inhibition of 5-HT3 receptors-activated currents by cannabinoids in rat trigeminal ganglion neurons

This study investigated the modulatory effect of synthetic cannabinoids WIN55,212-2 on 5-HT3 receptor-activated currents (I5-HT3) in cultured rat trigeminal ganglion (TG) neurons using whole-cell patch clamp technique. The results showed that: (1) The majority of examined neurons (78.70%) were sensitive to 5-HT (3-300 μmol/L). 5-HT induced inward currents in a concentration-dependent manner and the currents were blocked by ICS 205-930 (1 μmol/L), a selective antagonist of the 5-HT3 receptor; (2) Pre-application of WIN55,212-2 (0.01-1 μmol/L) significantly inhibited I5-HT3 reversibly in concentration-dependent and voltage-independent manners. The concentra-tion-response curve of 5-HT3 receptor was shifted downward by WIN55,212-2 without any change of the threshold value. The EC50 values of two curves were very close (17.5±4.5) mmol/L vs. (15.2±4.5) mmol/L and WIN55,212-2 decreased the maximal amplitude of I5-HT3 by (48.65±4.15)%; (3) Neither AM281, a selective CB1 receptor antagonist, nor AM630, a selective CB2 receptor antagonist re-versed the inhibition of I5-HT3 by WIN55,212-2; (4) When WIN55,212-2 was given from 15 to 120 s before 5-HT application, inhibitory effect was gradually increased and the maximal inhibition took place at 90 s, and the inhibition remained at the same level after 90 s. We are led to concluded that-WIN55,212-2 inhibited I5-HT3 significantly and neither CB1 receptor antagonist nor CB2 receptor an-tagonist could reverse the inhibition of I5-HT3 by WIN55,212-2. Moreover, WIN55,212-2 is not an open channel blocker (OCB) of 5-HT3 receptor. WIN55,212-2 significantly inhibited 5-HT-activated currents in a non-competitive manner. The inhibition of I5-HT3 by WIN55,212-2 is probably new one of peripheral analgesic mechanisms of WIN55,212-2, but the mechanism by which WIN55,212-2 in-hibits I5-HT3 warrants further investigation.     

胺碘酮和维拉帕米对体外激活的淋巴细胞分泌细胞因子的影响

目的研究胺碘酮（AMI）和维拉帕米（VER）对体外脂多糖（LPS）激活的人外周血淋巴细胞分泌细胞因子的影响，初步探讨此类药物发挥免疫调节作用的机理。方法AMI和VER作用于LPS激活的人外周血淋巴细胞，用双抗体夹心酶联免疫吸附法检测培养液上清中细胞因子白介素2（IL-2）、肿瘤坏死因子α（TNF-α）、白介素10（IL-10）和转化生长因子既（TGF-β1）水平。结果AMI和VER均可浓度依赖性抑制IL-2、TNF-α和TGF-β1的分泌，提高IL-10的分泌。结论AMI和VER通过对体外淋巴细胞的直接作用调节细胞因子的产生，淋巴细胞膜离子通道可能为其作用靶点之一。     

心房IKur通道阻滞剂治疗心房颤动的动向

心房颤动(Af)在老年患者中最为常见,目前尚无安全有效的治疗方法。现在的研究结果表明:选择性的Kv1.5阻滞剂将可能成为新一代强效安全的抗Af药。1Af发病情况尽管难以准确估计Af的发病率,但粗略估计在美国、欧洲和日本超过1000万人患有Af,预计到2017年将超过1350万。在Af患者中,超过60%的患者年龄为>75岁,另外有25%的患者年龄为65～74岁。美国和欧洲人口老龄化状况会导致患者数量的持续增长。Af可诱发充血性心力衰竭,并可增加3.0倍以上血管栓塞性脑卒中的危险性和1.5倍以上的死亡率。2Af治疗现状现有许多抗心律失常药物,如多非利特、胺碘…