The anterior and posterior 'stomach' regions of larval Aedes aegypti midgut: regional specialization of ion transport and stimulation by 5-hydroxytryptamine.
The anterior and posterior 'stomach' regions of larval Aedes aegypti midgut: regional specialization of ion transport and stimulation by 5-hydroxytryptamine.
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埃及伊蚊幼虫中肠的前部和后部“胃”区域：离子运输和 5-羟色胺刺激的区域特化。
DOI：
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发表时间：
1999
影响因子：
2.8
通讯作者：
D. Moffett
中科院分区：
文献类型：
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作者：
T. Clark;A. Koch;D. Moffett
蚊幼虫中肠的“胃”区在组织学上可分为前后两个区域。在体外用生理盐水对称灌注的前胃具有-66 mV（管腔负）的初始跨上皮电位（TEP），其在10-15 min内衰减至接近-10 mV的稳态TEP，并维持至少1 h。在前胃中从未观察到管腔阳性TEPs。灌注后胃的初始TEP与前胃的极性相反，但幅度相似，测量为+75 mV（管腔阳性）。后胃的这种初始TEP首先迅速衰减，然后更缓慢地衰减，最终逆转上皮的电极性，因为在70分钟内在所有制备物中记录到管腔阴性TEP。（5-羟色胺，血清素）刺激两个区域，导致前胃的TEP的负偏转和后胃的TEP的正偏转。佛波醇12，13-二乙酸酯也引起前胃的TEP负偏转，但对后胃的TEP没有影响。这些数据表明，5-HT刺激区域特异性的离子转运机制在埃及伊蚊的胃，并建议，5-HT协调行动的马氏管和中肠在维持适当的血淋巴组成在体内。
The 'stomach' region of the larval mosquito midgut is divided into histologically distinct anterior and posterior regions. Anterior stomach perfused symmetrically with saline in vitro had an initial transepithelial potential (TEP) of -66 mV (lumen negative) that decayed within 10-15 min to a steady-state TEP near -10 mV that was maintained for at least 1 h. Lumen-positive TEPs were never observed in the anterior stomach. The initial TEP of the perfused posterior stomach was opposite in polarity, but similar in magnitude, to that of the anterior stomach, measuring +75 mV (lumen positive). This initial TEP of the posterior stomach decayed rapidly at first, then more slowly, eventually reversing the electrical polarity of the epithelium as lumen-negative TEPs were recorded in all preparations within 70 min. Nanomolar concentrations of the biogenic amine 5-hydroxytryptamine (5-HT, serotonin) stimulated both regions, causing a negative deflection of the TEP of the anterior stomach and a positive deflection of the TEP of the posterior stomach. Phorbol 12,13-diacetate also caused a negative deflection of the TEP of the anterior stomach, but had no effect on the TEP of the posterior stomach. These data demonstrate that 5-HT stimulates region-specific ion-transport mechanisms in the stomach of Aedes aegypti and suggest that 5-HT coordinates the actions of the Malpighian tubules and midgut in the maintenance of an appropriate hemolymph composition in vivo.