Revisiting the cellular mechanisms of strong luminal alkalinization in the anterior midgut of larval mosquitoes.
Revisiting the cellular mechanisms of strong luminal alkalinization in the anterior midgut of larval mosquitoes.
复制标题
DOI：
10.1242/jeb.023580
复制
发表时间：
2009-02
期刊：
影响因子：
--
通讯作者：
Moffett DF
中科院分区：
文献类型：
--
作者：
Onken H;Moffett DF
在这里，我们批判性地回顾了最近关于蚊子幼虫前中肠强碱化机制的两个假设以及我们对这些假设的检验。我们提出实验证据反对这些假设中提出的运输模式的主要组成部分。跨根尖和跨基底质子电化学梯度的测量提供了组织运输机制所面临和产生的驱动力的指示。这些测量证实了基础v - atp酶激活碱化。5 -羟色胺刺激v - atp酶，由此表明质子动力在基底膜上的增加。此外，神经激素导致细胞内ph值惊人地大幅增加。抑制剂研究结果表明，与先前的建议相反，碳酸酐酶显然不参与向各自的转运蛋白提供酸碱当量。此外，任何被认为参与碱分泌或酸吸收的根尖过程都必须是不依赖Cl -的，并且对DIDS、氨酰、Zn2+和瓦巴因不敏感。这些结果反驳了假定的顶端Cl−/HCO3−交换剂、顶端H+通道、顶端阳离子/质子交换剂的参与以及顶端Na+/K+泵的重要性。本文的研究结果为进一步研究该体系的强碱化机理提供了局限性和方向。
Here we critically review two recent hypotheses about the mechanism of strong alkalinization by the anterior midgut of mosquito larvae and our tests of these hypotheses. We present experimental evidence against the major components of transport models proposed in these hypotheses. Measurements of the transapical and transbasal proton electrochemical gradients provide an indication of driving forces faced by and generated by the transport mechanisms of the tissue. These measurements confirmed that basal V-ATPase energizes alkalinization. Serotonin stimulates the V-ATPase, as indicated by the ensuing increase in proton-motive force across the basal membrane. Moreover, the neurohormone resulted in a surprisingly large increase in the intracellular pH. The results of inhibitor studies indicate that, contrary to previous proposals, carbonic anhydrase is apparently not involved in supplying acid–base equivalents to the respective transporters. Furthermore, any apical processes proposed to be involved in alkali secretion or acid absorption must be Cl− independent and insensitive to DIDS, amiloride, Zn2+ and ouabain. These results argue against the involvement of putative apical Cl−/HCO3− exchangers, apical H+ channels, apical cation/proton exchangers and the importance of the apical Na+/K+ pump. The studies analyzed here thus provide both a limitation and direction for further studies of the mechanism of strong alkalinization in this system.
登录
查看更多内容
影响因子：
3.9
作者：
Luo, C;Clark, JW;Bidani, A
通讯作者：
Bidani, A
影响因子：
3.4
作者：
Grabe, M;Wang, HY;Oster, G
通讯作者：
Oster, G
影响因子：
2.8
作者：
Onken, H;Moffett, SB;Moffett, DF
通讯作者：
Moffett, DF
影响因子：
2.8
作者：
Okech, Bernard A.;Boudko, Dmitri Y.;Harvey, William R.
通讯作者：
Harvey, William R.
影响因子：
3.5
作者：
AZUMA, M;HARVEY, WR;WIECZOREK, H
通讯作者：
WIECZOREK, H