THE EFFECT OF bFGF ON THE CALICUM INFLUX IN SPIRAL GANGLION CELLS IN STREPTOMYCIN RELATED DEAFNESS / 解放军医学杂志

ABSTRACT

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 10?mol/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.