Department of Surgery, Seoul National University College of Medicine, Seoul, Korea.
J Korean Med Sci. 2012 Jul;27(7):777-83. doi: 10.3346/jkms.2012.27.7.777. Epub 2012 Jun 29.
Effective drug to manage constipation has been unsatisfactory. We sought to determine whether methionine has effect on the human colon. Human colon tissues were obtained from the specimens of colon resection. Microelectrode recording was performed and contractile activity of muscle strips and the propagation of the contractions in the colon segment were measured. At 10 µM, methionine depolarized the resting membrane potential (RMP) of circular muscle (CM) cells. In the CM strip, methionine increased the amplitude and area under the curve (AUC) of contractions. In the whole segment of colon, methionine increased the amplitude and AUC of the high amplitude contractions in the CM. These effects on contraction were maximal at 10 µM and were not observed in longitudinal muscles in both the strip and the colon segment. Methionine reversed the effects of pretreatment with sodium nitroprusside, tetrodotoxin and N(w)-oxide-L-arginine, resulting in depolarization of the RMP, and increased amplitude and AUC of contractions in the muscle strip. Methionine treatment affected the wave pattern of the colon segment by evoking small sized amplitude contractions superimposed on preexisting wave patterns. Our results indicate that a compound mimicking methionine may provide prokinetic functions in the human colon.
用于治疗便秘的有效药物一直不尽如人意。我们试图确定蛋氨酸是否对人体结肠有影响。从结肠切除标本中获得人结肠组织。进行微电极记录，测量肌条的收缩活动和结肠节段收缩的传播。在 10µM 时，蛋氨酸使环形肌（CM）细胞的静息膜电位（RMP）去极化。在 CM 条带中，蛋氨酸增加了收缩的幅度和曲线下面积（AUC）。在整个结肠节段中，蛋氨酸增加了 CM 中高振幅收缩的幅度和 AUC。这些收缩的影响在 10µM 时达到最大值，在 CM 条带和结肠节段的纵肌中均未观察到。蛋氨酸逆转了预处理时使用硝普钠、河豚毒素和 N（w）-氧化物-L-精氨酸的作用，导致 RMP 去极化，并增加了肌条的收缩幅度和 AUC。蛋氨酸治疗通过引发叠加在现有波型上的小幅度收缩来影响结肠节段的波型。我们的结果表明，一种模拟蛋氨酸的化合物可能会为人结肠提供促动力功能。
