Bortolotti M, Mari C, Lopilato C, La Rovere L, Miglioli M
Department of Internal Medicine and Gastroenterology, University of Bologna, Italy.
Aliment Pharmacol Ther. 2001 Feb;15(2):157-61. doi: 10.1046/j.1365-2036.2001.00917.x.
Sildenafil shows an intense and prolonged inhibitory effect on the smooth muscle cells of corpus cavernosum arterioles by blocking phosphodiesterase-type 5, which inactivates the nitric oxide-stimulated cyclic guanosine monophosphate.
To investigate whether this inhibitory effect is also displayed on the musculature of the gastroduodenal tract.
In 16 normal subjects, antroduodenal motility was recorded by means of a low-compliance manometric system. Ten minutes after the appearance of a phase III of the migrating motor complex, a tablet of sildenafil 50 mg, dissolved in 20 mL of water, was infused in the gut of eight patients, or a placebo in the other eight patients, randomly and in a double-blind manner, continuing the recording for 90 min. The frequency and amplitude of antral and duodenal waves, measured during the first 60 min after infusion in the two groups, were compared statistically. In addition, the duration of antral and duodenal phases I, and the number of phases III occurring during the whole 90 min after infusion, were compared in the two groups.
Antral and duodenal wave frequency and amplitude were significantly lower during the first 60 min after sildenafil administration. Both antral and duodenal phases I were significantly longer after sildenafil than after placebo, and the number of phases III which occurred during the 90 min after sildenafil was significantly lower than after placebo.
Sildenafil inhibits interdigestive motor activity of the antrum and duodenum.
西地那非通过阻断5型磷酸二酯酶对海绵体小动脉的平滑肌细胞产生强烈而持久的抑制作用，该酶可使一氧化氮刺激的环磷酸鸟苷失活。
研究这种抑制作用是否也表现在胃十二指肠的肌肉组织上。
对16名正常受试者，采用低顺应性测压系统记录胃十二指肠运动。在移行运动复合波III期出现10分钟后，将一片50毫克的西地那非溶解于20毫升水中，随机、双盲地注入8名患者的肠道，另外8名患者注入安慰剂，继续记录90分钟。比较两组在注入后前60分钟内测量的胃窦和十二指肠波的频率和振幅。此外，比较两组胃窦和十二指肠I期的持续时间，以及注入后整个90分钟内出现的III期次数。
服用西地那非后的前60分钟内，胃窦和十二指肠波的频率和振幅显著降低。服用西地那非后，胃窦和十二指肠I期均比服用安慰剂后显著延长，且服用西地那非后90分钟内出现的III期次数显著低于服用安慰剂后。
西地那非抑制胃窦和十二指肠的消化间期运动活性。
