^1H-NMR Analysis on Histamine Release Mechanism in Mast Cells.

1.在完整肥大细胞的~1H-核磁共振谱中，检测到两条组胺的宽共振线。然而，这些信号不是通过预饱和技术检测到的。这一结果表明，组胺分子在细胞内的颗粒中处于一定的结合状态。当在肥大细胞悬液中加入化合物48/80诱导胞吐时，出现明显的游离组胺共振线，同时乳酸的共振性增加。因此，颗粒的胞吐作用导致肥大细胞释放组胺，并伴随着糖酵解的激活。当悬浮在等渗蔗糖溶液中的细胞被诱导胞吐时，我们发现结合组胺的共振线在光谱中保持不变。当在悬浮液中加入氯化钠时，出现了游离组胺的共振线。结果表明，肥大细胞释放组胺的机制分为两个步骤。在最初的步骤中，细胞内的胞吐作用导致颗粒释放到细胞外介质中。然后，组胺分子从颗粒中释放出来，被钠离子取代。

1. In ^1H-NMR spectra of intact mast cells two broad resonance lines of histamine were detected. However, these signals were not detected by a presaturation technique. This result indicates that the histamine molecules are in a certain "bound" state in the granules in the cells.2. When exocytosis was induced by adding compound 48/80 to a suspension of mast cells, sharp resonance lines of free histamine appeared, together with an increase in the resonance of lactate. Thus, exocytosis of granules caused histamine release from the mast cells, accompanied with glycolysis activation.3. When exocytosis was induced in the cells suspended in an isotonic sucrose solution, we found that the resonance lines of bound histamine remained unchanged in the spectra. When sodium chloride was added into the suspension, the resonance lines of free histamine appeared. The results indicate that the mechanism of histamine release from mast cells consists of two steps. On the initial step exocytosis in the cells causes the release of the granules into the extracellular medium. Then, the histamine molecules are released from the granules, replaced with sodium ions.