[外分泌腺中的离子电流与分泌]

[Ionic currents and secretion in the exocrine glands].

作者信息

Marty A

出版信息

J Physiol (Paris). 1985;80(2):111-9.

Abstract

Exocrine glands extrude both proteins and salt. Fluid secretion is related to a modification of the membrane permeability of secreting cells. This permeability change may be measured as an increase of labelled ion fluxes or as a rise of membrane conductance. It involves Na+, K+, Cl- and Ca2+ ions. Intracellular Ca2+ acts as "second messenger" in the development of the electrical response. Recent recordings using the "patch-clamp" technique have revealed three types of ion channel activated by secretory agents. These channels are sensitive to internal Ca2+ ions. They are respectively selective to K+, Cl- and positively charged monovalent ions. Two models suggesting possible roles for these channels in the secretion process are presented. However, evaluation of such models is presently restricted by numerous uncertainties on the function of secreting cells in vivo. Information is notably lacking concerning the exact composition of the secreted fluid, and the exchanges between exocrine glands and blood circulation.

摘要

外分泌腺可排出蛋白质和盐分。液体分泌与分泌细胞的膜通透性改变有关。这种通透性变化可通过标记离子通量的增加或膜电导的升高来测量。它涉及Na⁺、K⁺、Cl⁻和Ca²⁺离子。细胞内Ca²⁺在电反应的发生过程中充当“第二信使”。最近使用“膜片钳”技术的记录揭示了三种由分泌因子激活的离子通道。这些通道对细胞内Ca²⁺离子敏感。它们分别对K⁺、Cl⁻和带正电荷的单价离子具有选择性。提出了两种关于这些通道在分泌过程中可能作用的模型。然而，目前对这些模型的评估受到体内分泌细胞功能众多不确定性的限制。尤其缺乏关于分泌液的确切成分以及外分泌腺与血液循环之间交换的信息。