摘要
目的为研究β3肾上腺素能受体介导的心脏生物学效应--β3肾上腺素能受体激活后心肌细胞电生理活动的变化。方法以原代培养的豚鼠心肌细胞为对象,采用全细胞膜片钳技术记录心肌细胞孵育β3肾上腺素能受体激动剂4-[-[2-hydroxy-(3-chlorophenyl)ethyl-amino]propyl]phenoxyacetate(BRL-37344;BRL)5～10min前后ICa-L,Ito(L型钙离子通道和瞬时外向钾通道)的变化。结果显示10-6mol/L的BRL显著增强豚鼠心肌细胞的Ito,上移I-V曲线;去极化刺激到+80mV时,电流密度从(6.11±1.03)pA/pF上升到(8.46±2.07)pA/pF(n=6,P=0.013064)。10-6mol/L的BRL显著增强豚鼠心肌细胞的ICa-L,为对照组的(2.30±0.75)倍(n=5,P=0.0063);去极化刺激到+10mV时,电流幅度从(89.25±17.83)pA上升到(205.00±72.24)pA。结论 BRL-37344可增强豚鼠心肌瞬时外向钾电流和L型钙电流,进而调控心脏的活动。
Objective To study the biological effect of β3 adrenoceptor-activated electrophysiological activities in cardiac myocytes. Methods Changes of transient outward potassium （ Ito） and L-type calcium current （ ICa-L） in primary cultured guinea pig cardiacmyocytes were detected with the standard whole-cell patch clamp technique about 5 -10 min before and after administration of β3 adrenoceptor agonist,4--2-hydroxy-（ 3-chlorophenyl） ethyl-aminopropylphenoxyacetate （ BRL-37344; BRL）. Results BRL could significantly increased the Ito in guinea pig cardiac myocytes with the I-V curve up-moved. When the membrane potential reached to ＋ 80 mV,the density current increased from 6. 11 ± 1. 03 pA/pF to 8. 46 ± 2. 07 pA/pF （ n = 6,P =0. 013 064）. BRL （ 10 -6mol/L） could significantly increase the ICa-Lin guinea pig cardiac myocytes,which was （ 2. 30 ±0. 75） -fold higher than in control group（ n =5,P =0. 0063）. When the membrane potential increased to ＋ 10 mV ,the current,increased from 89. 25 ± 17. 83 pA to 205. 00 ± 72. 24 pA （ n = 5,P = 0. 006 3）. Conclusion BRL-37344 can increase the transient Itoand ICa-L,thus further regulating the cardiac activities.
出处
《第三军医大学学报》
CAS
CSCD
北大核心
2010年第11期1192-1194,共3页
Journal of Third Military Medical University
