Signaling molecules stored in cellular granules serve a broad range of functional purposes. Serotonin, for example, is involved in the regulation of behavior, cognitive function, and hemostasis. Understanding serotonin release from platelet granules can provide valuable fundamental information about the exocytotic process and help elucidate potential abnormalities of diseased platelets. Experimentally, carbon-fiber microelectrochemistry has been utilized to characterize the dynamic behavior of serotonin secretion from individual platelets. The objectives of this study were (1) to develop a finite-element model of the carbon-fiber microelectrode experiment and (2) to predict the effect of the postulated core-halo granule microstructure and rate of fusion pore expansion on the resulting amperometric signal. The model confirmed that the core-halo microstructure is consistent with the observed amperometric spike profiles. Further, it showed that the ratio of pore diameter to granule diameter, rather than the rate of pore expansion, dictates the profile shape. Understanding the driving forces for chemical messenger delivery from platelet granules has implications for understanding abnormalities in diseased platelets as well as other exocytotic cells.

中文翻译：

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粒状5-羟色胺胞吐作用的有限元模型。

存储在细胞颗粒中的信号分子具有广泛的功能目的。例如，血清素参与行为，认知功能和止血的调节。了解血小板颗粒中5-羟色胺的释放可以提供有关胞吐过程的有价值的基本信息，并有助于阐明患病血小板的潜在异常。实验上，碳纤维微电化学已用于表征单个血小板中血清素分泌的动态行为。这项研究的目的是（1）建立碳纤维微电极实验的有限元模型，以及（2）预测假定的芯-晕颗粒结构和熔融孔扩展速率对所得安培信号的影响。该模型证实了芯-晕的微观结构与观察到的安培峰分布一致。此外，表明孔直径与颗粒直径的比而不是孔膨胀率决定了轮廓形状。理解从血小板颗粒递送化学信使的驱动力对于理解患病的血小板以及其他胞吐细胞的异常具有启示。