Abstract: | The effect of PGE1 on peristalsis of guinea-pig isolated ileum was examined using a modified Trendelenburg method to evoke and record peristaltic activity. PGE1 (14 nM, 0.11 microM and 0.56 microM) increased peristaltic activity of both longitudinal and circular muscle, mainly by increasing the amplitude of contraction. Preparations of ileum subjected to a 'minimal' peristaltic stimulus were more sensitive to the effects of PGE1 than were preparations subjected to a 'just-maximal' peristaltic stimulus. The inhibition of peristaltic activity caused by perivascular nerve stimulation was antagonized by 0.56 microM PGE1 but slightly increased by 14 nM PGE1. |