Cholinergic mechanism of acid secretion in the dog: an in vivo and in vitro comparison.
Cholinergic mechanism of acid secretion in the dog: an in vivo and in vitro comparison.
复制标题
狗酸分泌的胆碱能机制：体内和体外比较。
DOI：
10.1016/0014-2999(84)90725-8
复制
发表时间：
1984
影响因子：
5
通讯作者：
Nies,AS
中科院分区：
文献类型：
--
作者：
Gerber,JG;Payne,NA;Fadul,S;Nies,AS
在杂种犬中，使用体内和体外制剂进行比较，检查胆碱能刺激对胃酸分泌的影响。胃瘘犬用于体内研究，乙酰甲胆碱直接输注到供应胃底的动脉中，以避免全身血流动力学变化。分离的壁细胞用于体外研究。在体内，乙酰甲胆碱以1 μg/min的速度输注可刺激胃酸分泌，静脉注射甲硫氨酰胺（H2受体阻滞剂）可抑制胃酸分泌98.5 ± 1.4%，动脉注射胰高血糖素可抑制胃酸分泌72 ± 11%。胰高血糖素对组胺刺激的胃酸分泌无影响。在体外，乙酰甲胆碱浓度从10−7、10− 6增加到10− 5 M，以浓度依赖性方式刺激壁细胞摄取[14 C]氨基比林。10− 4 M甲硫酰胺或10− 6 M胰高血糖素不会改变乙酰甲胆碱的这种作用。然而，阿托品10− 5 M完全阻断了乙酰甲胆碱的刺激作用。我们的数据表明，胆碱能机制的酸分泌是不同的，即使在同一物种在体内与体外检查。体内组胺依赖性对酸分泌的胆碱能机制有主要贡献，而体外胆碱能激动剂与毒蕈碱受体的相互作用导致酸刺激，不需要组胺的存在。
The effect of cholinergic stimulation on gastric acid secretion was examined in mongrel dogs using an in vivo and an in vitro preparation for comparison. The gastric fistula dog was used for the in vivo studies, and methacholine was infused directly into the artery supplying the fundus of the stomach to avoid systemic hemodynamic changes. Isolated parietal cells were used for the in vitro studies. In vivo, methacholine infused at 1 μg/min was found to stimulate gastric acid secretion that was inhibited 98.5 ± 1.4% by intravenously administered metiamide (H2blocker) and 72 ± 11% by intra-arterially administered glucagon. Glucagon had no effect on histamine stimulated acid secretion. In vitro, increasing concentrations of methacholine from 10−7, 10−6to 10−5M stimulated [14C]aminopyrine uptake into parietal cells in a concentration dependent manner. This effect of methacholine was unaltered by 10−4M metiamide or 10−6M glucagon. However, atropine 10−5M totally blocked the stimulatory effect of methacholine. Our data suggest that the cholinergic mechanism of acid secretion is different when examined in vivo vs. in vitro even in the same species. In vivo histamine dependency has a major contribution to the cholinergic mechanism of acid secretion, whereas in vitro the interaction of the cholinergic agonist at the muscarinic receptor results in acid stimulation that does not require the presence of histamine.