八肽胆囊收缩素激活钙离子通道和酪氨酸激酶诱导豚鼠心肌细胞内的游离钙增高(英文)  

Cholecystokinin octapeptide increases free intracellular calcium of guinea pig cardiomyocytes through activation of Ca^(2+) channel and tyrosine kinase

作　　者：赵晓云 凌亦凌[2] 尚忠林[3] 李清[4] 尹京湘[4] 檀国军[4] 

机构地区：[1]河北省老年医学重点实验室,石家庄050051 [2]河北医科大学病理生理教研室,石家庄050017 [3]河北师范大学生命科学学院,石家庄050017 [4]河北医科大学生理教研室,石家庄050017

出　　处：《生理学报》2004年第1期31-35,共5页Acta Physiologica Sinica

基　　金：This work was supported by the grants of Education Committee of Hebei Province(No.200122).

摘　　要：探讨八肽胆囊收缩素(CCK-8)对豚鼠单个心肌细胞内游离钙浓度([Ca2+]i)的影响及其信号转导机制。Fluo 3-AM标记酶消化法分离的单个心室肌细胞,用激光共聚焦显微镜测定细胞内[Ca2+]i的浓度。[Ca2+]i的变化用荧光强度(Fi)和相对荧光强度(Fi/F0％)表示。实验结果如下:(1)在含Ca2+1.0 mmol/L的Tyrode’s液中,CCK-8(1-104pmol/L)均可引起[Ca2+]i快速显著上升(P<0.01)。(2)用钙离子鳌合剂EGTA(3 mmol/L)和钙离子通道阻断剂nisoldipine(0.5μmol/L)预孵育心肌细胞5 min,CCK-8(102pmol/L)仅可引起[Ca2+]i缓慢轻度上升(P<0.01)。(3)用非选择性CCK受体拮抗剂丙谷胺(proglumide 6μmol/L)或酪氨酸激酶抑制剂genistein(1μmol/L)预孵育心肌细胞5 min,则完全抑制CCK-8诱导的[Ca2+]i升高(P<0.01)。 CCK-8可通过激活其受体控制的Ca2+通道,引起Ca2+内流,诱导细胞内Ca2+释放,引起豚鼠单个心肌细胞内[Ca2+]i上升,此作用可能由酪氨酸激酶介导。The aim of the present study was to explore the effect of cholecystokinin octapeptide (CCK-8) on [Ca2+]i and its signal transduction mechanism in isolated guinea pig cardiomyocytes. [Ca2+]i was measured by laser scanning confocal microscopy in single ventricular myocytes which were dissociated by enzymatic dissociation method and loaded with Fluo 3-AM. The changes in [Ca2+]i were represented by fluorescent intensity (F.) or relative fluorescent intensity (Fi/F0%). The results obtained are as follows. (1) In the normal Tyrode's solution containing 1.0 mmol/L Ca2+, CCK-8 (1-104pmol/L) elicited a rapid and marked increase in [Ca2+]i. (2) When cardiomyocytes were pretreated with the Ca2+ chelator EGTA (3 mmol/L) and Ca2+ channel antagonist nisoldipine (0.5 μmol/L) for 5 min, CCK-8 (102 pmol/L) caused a slow and small increase in [Ca2+]i (P< 0.01). (3) Pretreatment with the nonselected CCK- receptor (CCK-R) antagonist proglumide (6μmol/L) or the tyrosine kinase inhibitor genistein (1 μmol/L) for 5 min could inhibit the increase of [Ca2+]i induced by CCK-8 (102 pmol/L) (P<0.01). The results suggest that CCK-8 increases the [Ca2+]i via activating the receptor-operated Ca2+ channel and eliciting the influx of Ca2+ in isolated guinea pig cardiomyocytes, in which tyrosine kinase may be involved.

关 键 词：八肽胆囊收缩素 心肌细胞 荧光强度 钙通道 共聚焦显微镜 受体 

分 类 号：R33[医药卫生—人体生理学]