烧伤血清对大鼠心肌细胞钙稳态的影响  

The effect of burn sera on the calcium homeostasis in isolated rat myocardial cells

作　　者：沈洪兴[1] 陈玉林[1] 刘世康[1] 梅岩艾[2] 黄洛秀[2] 夏照帆[1] 

机构地区：[1]上海长海医院烧伤科,200433 [2]复旦大学生命科学院

出　　处：《中华烧伤杂志》2000年第3期141-144,共4页Chinese Journal of Burns

基　　金：国家自然科学基金!资助项目 ( 39470 70 9)

摘　　要：目的　观察烫伤血清对成年大鼠分离的心肌细胞游离钙浓度 [(Ca2 + )i]及胞膜钙通道电流的影响 ,探讨烧伤引起的心肌细胞钙稳态变化。　方法　伤后 2、4、6h分离 30 %TBSAⅢ度烧伤SD大鼠血清 ,简称 2hBS、4hBS、6hBS ;逆行循环灌流、胶原酶消化分离心肌细胞 ;Fura - 2 /AM荧光染色法测定 [Ca2 + ]i;膜片钳技术全细胞记录模式测定细胞膜钙通道电流。　结果　正常心肌细胞[Ca2 + ]i为 (10 1.3± 2 1.3)nmol/L ,烧伤血清可使心肌细胞 [Ca2 + ]i显著升高。 (P <0 .0 1) ,以 6hBS的作用最强 ;钙通道阻断剂异搏定 (30mmol/L)和肌浆网rynodine受体拮抗剂普鲁卡因 (2mmol/L)均非常显著地抑制 6hBS的作用 (P <0 .0 1) ,抑制率分别为 47.7%和 6 7.6 % ,后者强于前者 (P <0 .0 1) ,2hBS使峰值L型钙电流 (ICa -L)比对照组增加 5 0 80 % ;而 6hBS使峰值ICa -L增加 1 5 2 .5倍 ;峰值电流 -电压曲线显示烧伤血清明显增加各个去极化钳制电压下的ICa ,并使得最大激活电压提前 ;细胞外液灌洗可祛除烧伤血清对钙电流的作用。　结论　烧伤血清能使心肌细胞 [Ca2 + ]i,和膜上钙通道电流显著升高 。Objective To study the effect of burn sera on the calcium homeostasis in isolated rat myocardial cells. Methods The burn sera were obtained from the Sprague-Dawley(SD) rats inflicted by 30%TBSA Ⅲ degree burn at 2, 4 and 6 postburn hours with the harvesting of burn sera at different postburn times, named as 2 hBS, 4hBS and 6 hBS, respectively. Myocardial cells were isolated by enzyme digestion with retrograde perfusion apparatus. [Ca 2+ ]i was detected with the fluorescent dye Fura-2 and L-type calcium(ICa-L) currents were recorded in the whole-cell patch-clamp model. Results Myocardial cellular [Ca 2+ ]i became much higher in content after being in cubated with sera, especially with 6hBS, than that in normal myocardial cells (P<0.01). But the effect of 6hBS could be significantly inhibited by verapamil (30nmol/L), the calcium channel antagonist and procaine (2 mmol/L), the inhibitor of rynodine receptor (P< 0.01) by 47.7% and 67.6% , respectively. Ca-L was evidently increased by the stimulation of 2 hBS and 6 hBS, by 50-80% and 1.5-2.5 folds, respectively. It was indicated by I-V curves that every ICa caused by depolarizaton and clamp voltage was increased by burn sera, which further made the maximal activating voltage ahead of time. All the burn sera effects on calcium current could be removed by extracellular lavage. Conclusion The myocardial [Ca 2+ ]i and ICa-L could increase significantly when affected by burn sera. The alteration in calcium homeostasis might be a cellular mechanism of myocardial injury.

关 键 词：烧伤 血清 大鼠 心肌细胞 钙稳态 膜片钳术 

分 类 号：R644[医药卫生—外科学]