用电子探针X射线显微分析法研究肾上腺素激发的心房特殊颗粒分泌(英文)

Using electron probe X-ray microanalysis to study calcium release from atrial specific granules induced by injection of adrenaline in rats

本文研究心房特殊颗粒 (ASG)中的钙释放是否能促进颗粒内容的分泌。冷冻超薄切片技术和磷钨酸—乙醇 (EPTA)特殊染色技术制备大鼠心房切片。X射线显微定量分析采用Hall连续谱法 ,用以测量在肾上腺素处理后 15、30、6 0和 12 0min时ASG中钙含量的变化。用形态计量法的数密度作为判断ASG分泌状态的指标。结果显示心房特殊颗粒在生理状态下钙浓度高达 80mmol 公斤·干重。在肾上腺素注射后ASG的数密度逐渐下降 ,并于注射后 6 0min时下降至最低 ;ASG中的钙含量亦逐渐减低 ,但于注射后 30min即达最低 ,由此可见ASG钙含量的下降出现早于颗粒数的下降。推想肾上腺素处理引起的钙释放可能成为一种信号 ,启动心房肽的分泌 ,因此ASG在心房心肌细胞中可能具有细胞内钙库机能。

Whether the release of Ca from atrial specific granules (ASG) can promote ASG secretion was studied. The ultrathin cryosections and ethanolic phosphotungstic acid staining sections of rat atrial cardiocytes were prepared. Quantitative electron probe X ray microanalysis of Hall continuum method was adopted to measure the alteration of Ca content in ASG at the exact time intervals of 15, 30, 60, 120 min after the adrenaline (Ad) administration. The numerical density (N v ) was measured to estimate the ASG secretion. It was observed that the N v of ASG gradually decreased and reached the lowest value at the time of 60 min after the Ad administration. Meanwhile, the Ca content of ASG gradually decreased and reached the lowest value at the time of 30 min after the Ad administration. It showed that the decrease in Ca content took place earlier than that of ASG number. Accordingly, it suggested that the Ca released from ASG due to Ad stimulation might become a messenger triggering atrial natriuretic peptide secretion. The quantitative electron probe X ray microananlysis of Hall continuum method was discussed in this paper.