Fedirko N V, Man'ko V V, Klevets' M Iu
Ivan Franko Nataional University of Lviv.
Fiziol Zh (1994). 2001;47(3):35-41.
It has been shown, less concentrations of p-chlormercuribenzoate (1 and 2.5 mM) increased Ca2+ content in gland tissue and thereby protein secretion level that may occurred mainly by suppression Ca(2+)-pump or/and stimulation of Na(+)-Ca(2+)-exchange (both in cell plasma membrane) through modulation of SH-groups which form part of their molecules. Higher PCMB concentrations markedly decreased Ca2+ content in gland tissue as well as protein secretion. Effects of PCMB (5 and 10 mM), depending on the direction of Na(+)-Ca(2+)-exchange functioning (Ca(2+)-efflux or Ca(2+)-influx), were evoked or presumably by suppression of endoplasma reticulum Ca(2+)-pump (at conditions Na(+)-dependent Ca(2+)-efflux) or Na(+)-dependent Ca(2+)-influx into the cells that clearly confirmed when PCMB was added on the background of eosin Y (specific Ca(2+)-ATPase inhibitor). Possible role of potential dependent Ca(2+)-channnels in the mediating of PCMB effects is discussed. Introducing of dythiothreitol (DTT) increased Ca2+ content in glands and decreased secretion level obviously by protection of SH-groups of cell Ca(2+)-transporting systems and thereby diminished [Ca2+]i. Finally, we confirm important functional role of SH-groups in the regulation of Ca(2+)-homeostasis in secretory cells of exocrine glands.
已表明，较低浓度的对氯汞苯甲酸（1和2.5 mM）会增加腺体组织中的Ca2+含量，从而提高蛋白质分泌水平，这可能主要是通过抑制Ca(2+)-泵或/和刺激Na(+)-Ca(2+)-交换（均在细胞质膜中）来实现的，其机制是通过调节构成这些分子一部分的SH基团。较高浓度的PCMB会显著降低腺体组织中的Ca2+含量以及蛋白质分泌。PCMB（5和10 mM）的作用取决于Na(+)-Ca(2+)-交换的功能方向（Ca(2+)-外流或Ca(2+)-内流），可能是通过抑制内质网Ca(2+)-泵（在Na(+)-依赖的Ca(2+)-外流条件下）或抑制Na(+)-依赖的Ca(2+)-内流入细胞来引发的，当在曙红Y（特异性Ca(2+)-ATP酶抑制剂）背景下添加PCMB时，这一点得到了明确证实。文中讨论了电位依赖性Ca(2+)-通道在介导PCMB作用中的可能作用。加入二硫苏糖醇（DTT）可增加腺体中的Ca2+含量，并通过保护细胞Ca(2+)-转运系统的SH基团从而降低[Ca2+]i，明显降低分泌水平。最后，我们证实了SH基团在外分泌腺分泌细胞中Ca(2+)-稳态调节中的重要功能作用。
