EFFECT OF ETHANOL ON CHOLINE TRANSPORT IN RAT JEJUNUM
EFFECT OF ETHANOL ON CHOLINE TRANSPORT IN RAT JEJUNUM
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DOI：
10.1152/ajpgi.1985.249.2.g177
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发表时间：
1985-01-01
影响因子：
--
通讯作者：
TOMICIC, TK
中科院分区：
文献类型：
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作者：
HAJJAR, JJ;BAKER, ER;TOMICIC, TK
通过在体肠腔内灌注和体外刷状缘膜通量测量研究了乙醇对胆碱跨空肠转运的影响。通过胃管急性给予乙醇（4 g/kg）导致1 h内胆碱净吸收增加。通过用吡唑（一种乙醇代谢抑制剂）预处理来防止增加。慢性乙醇给药也引起胆碱吸收的增加，这种作用与乙醇摄入引起的营养变化无关。相反，通过灌注液直接滴入0.65 M乙醇不会引起胆碱吸收的变化，1.14 M溶液的灌注甚至会降低吸收。实验前1h灌胃乙醇预处理也能增强胆碱穿过离体大鼠空肠粘膜的体外流入。类似地，乙醇相关的内流率增加被吡唑抑制，但不受乙醛或乙酸的影响。像乙醇一样，用甲醇预处理大鼠刺激胆碱内流率。乙醇代谢而不是乙醇本身的直接作用刺激胆碱吸收和流入大鼠空肠。这种效应不是由乙醇、乙醛或乙酸盐的初级代谢产物产生的，但很可能与乙醇代谢的其他产物的刺激有关。
The effect of ethanol on choline transport across the rat jejunum was studied by intraluminal perfusion in vivo and by flux measurement across the brush-border membrane in vitro. Acute ethanol administration (4 g/kg) through a gastric tube caused an increase in net choline absorption within 1 h. The increase was prevented by pretreatment with pyrazole, an inhibitor of ethanol meatbolism. Chronic ethanol administration also caused an increase in choline absorption, the effect being unrelated to the nutritional changes that occur with ethanol ingestion. In contrast, direct instillation of 0.65 M ethanol through the perfusate caused no changes in choline absorption, and the perfusion of a 1.14 M solution even decreased absorption. The in vitro influx of choline across the mucosal membrane of the isolated rat jejunum was aslo enhanced by pretreatment with ethanol given by gavage 1 h prior to experimentation. Similarly, the ethanol-related increase in the influx rate was inhibited by pyrazole but was unaffected by acetaldehyde or acetate. Like ethanol, pretreatment of rats with methanol stimulated the choline influx rate. Ethanol metabolism rather than the direct effect of ethanol by itself stimulates the absorption and influx of choline into the rat jejunum. The effect is not produced by the primary metabolites of ethanol, acetaldehyde, or acetate but is very likely related to stimulation by other products of ethanol metabolism.