Adams W, Trafford A W, Eisner D A
Department of Veterinary Preclinical Sciences, University of Liverpool, Liverpool L69 3BX, UK.
Pflugers Arch. 1998 Oct;436(5):776-81. doi: 10.1007/s004240050701.
The effects of 2,3-butanedione monoxime (BDM) were examined using rat ventricular myocytes loaded with Indo-1 to measure the intracellular Ca concentration ([Ca2+]i). BDM (10 mM) produced a transient increase of the systolic Ca transient with no steady-state effect on its magnitude. This transient increase was more marked when BDM was applied after having decreased the external Ca concentration from 1 to 0.1 mM. There was a transient increase of resting [Ca2+]i in both quiescent and electrically stimulated cells. Prior application of BDM decreased the rise of [Ca2+]i produced by caffeine. In voltage-clamped cells the rise of [Ca2+]i produced by BDM was accompanied by a transient inward current attributed to the electrogenic Na-Ca exchange. The amount of Ca lost from the cell upon application of 10 mM BDM could be estimated either from the integral of the BDM-evoked current or from the reduction of the integral of a caffeine-evoked current and corresponded to about 50% of the sarcoplasmic reticulum (s.r.) Ca content. The decrease of s.r. Ca content and the transient potentiation of the systolic Ca transient suggest that BDM acts by stimulating Ca-induced Ca release. These effects must be allowed for when using BDM.
使用负载Indo-1的大鼠心室肌细胞来测量细胞内钙浓度（[Ca2+]i），以此研究2,3-丁二酮一肟（BDM）的作用。BDM（10 mM）使收缩期钙瞬变产生短暂增加，对其幅度无稳态影响。当外部钙浓度从1 mM降至0.1 mM后再应用BDM时，这种短暂增加更为明显。在静止和电刺激的细胞中，静息[Ca2+]i均出现短暂增加。预先应用BDM可减少咖啡因引起的[Ca2+]i升高。在电压钳制的细胞中，BDM引起的[Ca2+]i升高伴随着归因于电生性钠钙交换的短暂内向电流。应用10 mM BDM后从细胞中丢失的钙量可通过BDM诱发电流的积分或咖啡因诱发电流积分的减少来估计，约相当于肌浆网（s.r.）钙含量的50%。肌浆网钙含量的减少和收缩期钙瞬变的短暂增强表明，BDM通过刺激钙诱导的钙释放起作用。使用BDM时必须考虑到这些作用。
