粉防己碱对胎鼠大脑细胞游离钙含量的影响

结果表明,粉防己碱(Tet)非常明显地阻断K+去极化导致的胎鼠大脑[Ca²⁺]i含量的增加。经不同浓度Tet处理的大脑细胞加入KCl后,[Ca²⁺]i含量仍基本维持在静息状态下水平。对[Ca²⁺]i的阻断程度与Tet浓度无关。Tet对L-谷氨酸(L-Glu)所致大脑[Ca²⁺]i升高亦有明显抑制作用。10^-7mol·L^-1浓度的Tet还降低BayK8644引起的[Ca²⁺]i上升高。Tet能抑制高K⁺,二氢吡啶类钙激动剂及兴奋性神经递质导致的胎鼠大脑[Ca²⁺]i含量增加,提示Tet对神经细胞损伤可能有一定保护作用。

EFFECTS OF TETRANDRINE ON CYTOSOLIC FREE CALCIUM IN FETAL RAT CETEBRAL CELLS

Cytosolic free Ca²⁺─[Ca²⁺]i was measured in dissociated cerebral cells isolatedfrom fetal rats using the fluorescent indicater Fura-2.Increases in[Ca²⁺]i occurred rapidly followingexposure of the cells to 50 mmol·L^-1 KCl,10^-7 mol·L^-1 Bay K 8644 and 200 umol·L^-1 glu-tamate(Glu ).[ Ca²⁺]i elevation produced by K+ -depolarization was blocked completely by pretreat-ment with tetrandrine(Tet)of various concentrations(10^-9～10^-7 mol·L^-1,final).Tet showedsignificant inhibitory effect on[Ca²⁺]i increases stimufated by Glu in concentration-dependentmanner.With Tet 10^-7 mol·L^-1,Bay K 8644-induced increases in[Ca²⁺]i were reduced-markedly.These results indicate that Tet can block the increases in [Ca²⁺]i in fetal rat cerebral cellsinduced by Ca²⁺ agonists,suggesting that this drug may have a protective effect on cerebral cellinJury.