An improved in vitro bioassay for the study of 5‐HT4 receptors in the human isolated large intestinal circular muscle
An improved in vitro bioassay for the study of 5‐HT4 receptors in the human isolated large intestinal circular muscle
复制标题
用于研究人离体大肠环肌中 5-HT4 受体的改进体外生物测定法
DOI：
--
复制
发表时间：
2000
影响因子：
7.3
通讯作者：
J. Schuurkes
中科院分区：
文献类型：
--
作者：
N. H. Prins;N. Shankley;N. Welsh;M. Briejer;R. Lefebvre;L. Akkermans;J. Schuurkes
最近，研究表明，5-HT通过激活5-HT 4受体和5-HT 7受体诱导人结肠环行肌松弛。本研究的目的是开发一种新的人结肠体外生物测定法，以促进仅由5-HT 4受体介导的5-HT反应的药理学分析。与KCl（80 mM）收缩环形肌条产生了稳定的收缩张力，与毒蕈碱胆碱受体激动剂和组胺相反，自发收缩性大大降低。 这允许通过累积给药建立可重现的、完全定义的激动剂浓度-反应曲线。在这些条件下，5-HT诱导浓度依赖性舒张（pEC 50 7.31，Hill斜率0.91）。麦角新碱（10 μM）和格拉司琼（1 μM）均不影响5-HT诱导的舒张，表明5-HT 1、5-HT 2、5-HT 3、5-HT 5、5-HT 6或5-HT 7受体不参与。 河豚毒素（0.3 μM）无作用表明5-HT对平滑肌有直接作用。 选择性5-HT 4受体拮抗剂GR 113808、GR 125487和RS 39604竞争性拮抗5-HT诱导的舒张（pKB分别为9.43、10.12和8.53）。SB 204070（1 nM）产生了5-HT曲线的λ偏移（pA 2 10.34）和抑制。 这些亲和力估计值与先前报道的5-HT 4受体相似。选择性5-HT 4受体激动剂普卢卡必利和R 076186诱导舒张（pEC 50分别为7.50和7.57），GR 113808（3 nM）阻断了这一作用，得出的pA 2估计值分别为9.31和9.21。 总之，在KCl（80 mM）收缩的肌条中，5-HT通过激活均质平滑肌5-HT 4受体群诱导松弛。 这种新的生物测定法可以在体外对人结肠5-HT 4受体进行集中的药理学表征。
Recently, it was demonstrated that 5‐HT induces relaxation of human colon circular muscle through activation of 5‐HT4 receptors and 5‐HT7 receptors. The aim of the current study was to develop a new in vitro bioassay of human colon that would facilitate the pharmacological analysis of 5‐HT responses mediated solely by 5‐HT4 receptors. Contracting circular muscle strips with KCl (80 mM) yielded a stable contractile tension and, in contrast to muscarinic cholinoceptor agonists and histamine, a profound reduction of spontaneous contractility. This allowed the establishment of reproducible, fully‐defined, agonist concentration‐response curves by cumulative dosing. Under these conditions, 5‐HT induced a concentration‐dependent relaxation (pEC50 7.31, Hill slope 0.91). Neither methysergide (10 μM) nor granisetron (1 μM) affected the 5‐HT‐induced relaxation, suggesting that 5‐HT1, 5‐HT2, 5‐HT3, 5‐ht5, 5‐HT6 or 5‐HT7 receptors are not involved. The lack of effect of tetrodotoxin (0.3 μM) indicated a direct effect of 5‐HT on the smooth muscle. The selective 5‐HT4 receptor antagonists GR 113808, GR 125487 and RS 39604 competitively antagonized the 5‐HT‐induced relaxation (pKB 9.43, 10.12 and 8.53, respectively). SB 204070 (1 nM) produced a rightward shift (pA2 10.34) and depression of the 5‐HT curve. These affinity estimates are similar to those previously reported for 5‐HT4 receptors. The selective 5‐HT4 receptor agonists, prucalopride and R076186, induced relaxations (pEC50 7.50 and 7.57, respectively), that were blocked by GR 113808 (3 nM), yielding pA2 estimates of 9.31 and 9.21, respectively. To summarise, in KCl (80 mM)‐contracted muscle strips, 5‐HT induces relaxation through activation of a homogeneous smooth muscle 5‐HT4 receptor population. This new bioassay allows the focused, pharmacological characterization of human colonic 5‐HT4 receptors in vitro.
影响因子：
29.4
作者：
Grider, JR;Foxx-Orenstein, AE;Jin, JG
通讯作者：
Jin, JG
影响因子：
29.4
作者：
J. Kuemmerle;K. Murthy;J. Grider;D. Martin;G. Makhlouf
通讯作者：
J. Kuemmerle;K. Murthy;J. Grider;D. Martin;G. Makhlouf