碱性成纤维细胞生长因子对硫酸链霉素急性耳毒性影响的实验研究

THE EFFECT OF bFGF ON THE CALICUM INFLUX IN SPIRAL GANGLION CELLS IN STREPTOMYCIN RELATED DEAFNESS

采用激光共聚焦显微镜技术 ,以Fluo 3/AM负载后的豚鼠螺旋神经节细胞 (SGC)为实验对象 ,观察碱性成纤维细胞生长因子(bFGF)对其钙调控的影响以及这种影响与硫酸链霉素的拮抗效应。结果表明 ,高钾细胞外液和含 1nmol/LbFGF的正常细胞外液灌流可以导致SGC[Ca2 + ]i明显升高 ,钙升高的来源为细胞外钙离子的内流 ,bFGF和高钾细胞外液具有协同作用 ,硫酸链霉素可以阻断高钾细胞外液的致细胞内钙升高效应 ,bFGF可以拮抗硫酸链霉素的这种阻断作用 。

To evaluate the effect of bFGF on the calcium influx in SGCs and its antagonistical effect on streptomycin. The SGCs of guinea pig were isolated using an enzyme machine methods and loaded with 10μmol/L Fluo 3/AM for 30 min at 37℃,then cultured 60min at room temperature. Individual Fluo 3 loaded SGCs were examined with a confocal microscope (ACAS Ultima, USA) using a 20 x objective lens and linear scan mean.The level of SGCs[Ca 2+ ] i was steady within the process of normal extracellular liquid perfusion. SGCs[Ca 2+ ] i was increased when SGCs were perfused with 150mmol/L high potassium media(10/10) and normal media containing 1nmol/L bFGF(8/9), but the level of SGCs[Ca 2+ ] i did not change in high potassium free calcium media(9/9) and free calcium media containing 1nmol/L bFGF(10/11). After the treatment with 1 mmol/L streptomycin, the level of SGCs[Ca 2+ ] i was increased 1/11 and 5/12, respectively, when perfused high potassium media and bFGF media. And after being treated with 1nmol/L bFGF, high potassium media, SGCs[Ca 2+ ] i was increased more obviously and persisted for a longer time. After being treated with 1 mmol/L streptomycin, 0 1nmol/L, 1nmol/L and 10nmol/L bFGF, respectively, and 14/14 the level of SGCs[Ca 2+ ] i was increased 5/11, 9/12, and 14/14 when perfused high potassium media. High potassium media and bFGF perfusion could result in an increase of SGCs[Ca 2+ ] i ,and SGCs[Ca 2+ ] i increase was the result of calcium influx, and there was a synergic effect between high potassium and bFGF. Streptomycin could block the process of calcium influx induced by high potassium media, the blocking effect could be antagonized by bFGF, and the antagonistic effect was bFGF concentration dependent.