Kubota M, Ito Y, Domae M
Pflugers Arch. 1982 Oct 1;394(4):347-54. doi: 10.1007/BF00583700.
The effects of prostaglandins (PGs) and indomethacin on the mechanical and membrane properties of the smooth muscle cells of the guinea-pig ileocecal junction were studied using microelectrode and tension recording techniques and radioimmunoassay to determine levels of PGs. In the guinea-pig ileocecal junction, we found two distinct cell populations-cells with, and without spontaneous electrical and mechanical activities. PGs (PGE1, PGE2, PGF2 alpha) in low concentrations suppressed spontaneous mechanical activity. Correspondingly, PGs (greater than 10-7 M) suppressed both spontaneously generated spikes and evoked spikes, presumably due to an increase in the threshold for generation of action potential. On the contrary, indomethacin evoked rhythmic spontaneous contractions in the mechanically quiescent muscle preparations and reduced the PGE and PGF content of the muscle. Spontaneous spike discharges occurred during the indomethacin-induced contractions. The spontaneous electrical and mechanical activities induced by indomethacin were suppressed by PGs, in low concentrations. These results indicate that under physiological conditions, the endogenous PGs in the muscle may play an important role in regulation muscle tone as well as the membrane properties, thereby contributing to the regulation of motility of the intestine and possibly the sphincter.
利用微电极、张力记录技术以及放射免疫分析法测定前列腺素（PGs）水平，研究了前列腺素和吲哚美辛对豚鼠回盲部连接处平滑肌细胞力学和膜特性的影响。在豚鼠回盲部连接处，我们发现了两种不同的细胞群——具有和不具有自发电活动和机械活动的细胞。低浓度的PGs（前列腺素E1、前列腺素E2、前列腺素F2α）抑制自发机械活动。相应地，PGs（大于10 - 7M）抑制自发产生的峰电位和诱发峰电位，推测这是由于动作电位产生阈值增加所致。相反，吲哚美辛在机械性静止的肌肉标本中诱发节律性自发收缩，并降低肌肉中前列腺素E和前列腺素F的含量。在吲哚美辛诱导的收缩过程中出现自发峰电位发放。低浓度的PGs可抑制吲哚美辛诱导的自发电活动和机械活动。这些结果表明，在生理条件下，肌肉中的内源性PGs可能在调节肌张力以及膜特性方面发挥重要作用，从而有助于调节肠道以及可能的括约肌的运动。
