H2 receptors mediate cyclical chloride secretion in guinea pig distal colon.
H2 receptors mediate cyclical chloride secretion in guinea pig distal colon.
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DOI：
10.1152/ajpgi.1990.258.6.g887
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发表时间：
1990-06
期刊：
影响因子：
--
通讯作者：
Y. -. Wang;H. Cooke
中科院分区：
文献类型：
--
作者：
Y. -. Wang;H. Cooke
我们验证了组胺通过刺激粘膜下神经元上的H2受体介导豚鼠远端结肠离子分泌的假设。浆膜添加组胺引起短暂的短路电流（Isc）增加，随后是Isc的周期性反复增加。反应的瞬态阶段在以前被检查过，但在这些研究中没有被调查。组胺（1.5-2.5 × 10(-5) M）在1-2小时内每隔5分钟可引起Isc的峰值增加177 +/- 25 microA/cm2。每个循环周期的持续时间平均为2.1 +/- 0.3 min。H2激动剂地马匹利引起的循环比组胺引起的循环有更大的振幅。无论初始浓度如何，在组胺或diapprit存在时，反应的第一个周期的振幅总是小于随后的周期。对组胺、2-甲基组胺或地马匹利的周期性反应被H1阻滞剂吡拉胺改变，被H2拮抗剂西咪替丁减少，并被神经元阻滞剂河豚毒素消除。吡罗西康阻断前列腺素的形成并不能阻止复发周期。氯离子转运阻滞剂布美他尼和氯离子的去除抑制了循环。我们的研究结果表明，组胺通过激活参与调节上皮氯离子运输的粘膜下神经元上的H2受体，介导豚鼠远端结肠中氯离子的周期性分泌。
We tested the hypothesis that histamine mediates ion secretion in the guinea pig distal colon by stimulating H2 receptors on submucosal neurons. Serosal addition of histamine evoked a transient increase in short-circuit current (Isc) followed by recurrent cyclical increases in Isc. The transient phase of the response was examined previously and was not investigated in these studies. Histamine (1.5-2.5 x 10(-5) M) evoked a peak increase in Isc of 177 +/- 25 microA/cm2 at intervals of 5 min for 1-2 h. The duration of each recurrent cycle averaged 2.1 +/- 0.3 min. The H2 agonist dimaprit evoked recurrent cycles that had larger amplitudes than those caused by histamine. In the presence of histamine or dimaprit, the amplitude of the first cycle of the response was always less than subsequent cycles, regardless of the initial concentration. The cyclical responses to histamine, 2-methylhistamine, or dimaprit were unaltered by the H1 blocker pyrilamine, were reduced by the H2 antagonist cimetidine, and were abolished by the neuronal blocker tetrodotoxin. Blockade of prostaglandin formation with piroxicam did not prevent the recurrent cycles. The recurrent cycles were inhibited by the chloride transport blocker bumetanide and by removal of chloride ions. Our results demonstrate that histamine mediates prolonged cyclical chloride secretion in the guinea pig distal colon by activating H2 receptors on submucosal neurons involved in regulation of epithelial chloride transport.