Effects of atropine and tetrodotoxin on neurotensin-induced ileal sodium transport in the dog.
Effects of atropine and tetrodotoxin on neurotensin-induced ileal sodium transport in the dog.
复制标题
阿托品和河豚毒素对神经降压素诱导的狗回肠钠转运的影响。
DOI：
10.1111/j.1476-5381.1988.tb11506.x
复制
发表时间：
1988
影响因子：
7.3
通讯作者：
Mailman,D
中科院分区：
文献类型：
--
作者：
Mailman,D
1.用戊巴比妥钠麻醉犬，在静脉注射阿托品或动脉注射河豚毒素的情况下，静脉注射神经降压素。测定回肠内钠和血液的净流量和单向流量。同时测定动脉压、肠系膜静脉压、红细胞压积和血浆总固体含量。2.神经降压素引起钠净吸收的一过性增加，但与单向流量的显著变化无关。其次是长时间的净分泌，这与单向钠分泌的增加和钠吸收的较小下降有关。随着净钠分泌量的增加，钾素分泌量也随之增加。3.神经降压素升高红细胞压积和总固形物，降低动脉压，同时产生分泌物。4.阿托品可阻断神经降压素的所有心血管效应，并减弱神经降压素对吸收和分泌的早期作用，但不影响后期对分泌的作用。河豚毒素只阻断吸收的增加，但不能阻止分泌或心血管效应。5.神经降压素的心血管效应存在胆碱能步骤，神经降压素早期对分泌的影响是由于血浆液体漏出所支持的主动分泌。神经降压素对分泌的后期影响不是胆碱能步骤，主要是由于分泌活跃。这种吸收的增加部分是通过肠道的内在神经来调节的。
1. Neurotensin was infused intravenously, in the presence or absence of intravenous atropine or intraarterial tetrodotoxin, into dogs anaesthetized with sodium pentobarbitone. Net and unidirectional fluxes of sodium and blood flows in the ileum were measured. Arterial and mesenteric venous blood pressures, haematocrits and plasma total solids were also determined. 2. Neurotensin caused a transient increase in net sodium absorption which was not associated with significant changes in unidirectional fluxes. This was followed by prolonged net secretion which was associated with an increase in unidirectional sodium secretion and a smaller decrease in sodium absorption. Potassium secretion was also increased when net sodium secretion increased. 3. Neurotensin increased haematocrit and total solids and decreased arterial pressure at the same time that secretion occurred. 4. Atropine blocked all the cardiovascular effects of neurotensin and reduced its early effects on both absorption and secretion but not the later effects on secretion. Tetrodotoxin only blocked the increase in absorption but not the secretion or the cardiovascular effects. 5. It was concluded that there is a cholinergic step in the cardiovascular effects of neurotensin and that the early effects of neurotensin on secretion are due to active secretion supported by fluid leakage from the plasma. The later effects of neurotensin on secretion do not have a cholinergic step and are due primarily to an active secretion. The increased absorption is mediated partly through intrinsic nerves of the gut.