Mishima K, Kuriyama H
Jpn J Physiol. 1976;26(5):537-48. doi: 10.2170/jjphysiol.26.537.
Effects of prostaglandin E1, E2, and F2alpha (PGE1, PGE2, and PGF2alpha) on the electrical and mechanical properties of the smooth muscle of various areas of the guinea pig stomach were investigated. PGE1 and PGE2 (10(-9)-10(-6) g/ml) suppressed the spontaneously generated mechanical activity in circular muscle of the pylorus, but increased the activity of muscles in other areas of the stomach, while PFG2 alpha (10(-9)--10(-6) g/ml) showed excitatory action on muscles in all the areas of the stomach. These PG actions on the stomach muscle were mainly myogenic responses, and were not affected in the presence of tetrodotoxin (10(-7) g/ml). PGE1 and PGE2 (10(-8)-10(-6) g/ml) hyperpolarized the membrane and suppressed the generation of slow potential change in the circular muscle of the pylorus, thus causing the cessation of spikes which were superimposed on the slow potential change. On the other hand, these agents depolarized the membrane and increased membrane activity in the longitudinal muscle of the pylorus and both layers of the corpus. When voltage-current relationships were observed before and during application of PGs in the circular muscle of the pylorus, PGE1 and PGE2 consistently reduced membrane resistance at any given membrane potential level when compared with that in Krebs solution. In other regions of the stomach, PGE1 and PGE2 depolarized the membrane, and reduced the membrane resistance at any given membrane potential level. The differences of PG action on the various regions of stomach were compared with those observed in the other visceral smooth muscles.
研究了前列腺素E1、E2和F2α（PGE1、PGE2和PGF2α）对豚鼠胃不同区域平滑肌电特性和机械特性的影响。PGE1和PGE2（10⁻⁹ - 10⁻⁶ g/ml）抑制幽门环行肌自发产生的机械活动，但增加胃其他区域肌肉的活动，而PGF2α（10⁻⁹ - 10⁻⁶ g/ml）对胃所有区域的肌肉均表现出兴奋作用。这些前列腺素对胃肌肉的作用主要是肌源性反应，在存在河豚毒素（10⁻⁷ g/ml）时不受影响。PGE1和PGE2（10⁻⁸ - 10⁻⁶ g/ml）使幽门环行肌膜超极化，并抑制慢电位变化的产生，从而使叠加在慢电位变化上的锋电位停止。另一方面，这些药物使幽门纵行肌和胃体两层肌肉的膜去极化并增加膜活性。当在幽门环行肌中观察PGs应用前后的电压-电流关系时，与在Krebs溶液中相比，PGE1和PGE2在任何给定膜电位水平下均持续降低膜电阻。在胃的其他区域，PGE1和PGE2使膜去极化，并在任何给定膜电位水平下降低膜电阻。将前列腺素对胃不同区域的作用差异与在其他内脏平滑肌中观察到的差异进行了比较。
