Moreland R B, Kim N N, Nehra A, Parulkar B G, Traish A
Department of Urology, Boston University School of Medicine, MA 02118, USA.
Int J Impot Res. 2000 Apr;12(2):107-10. doi: 10.1038/sj.ijir.3900497.
Prostaglandin E1 (PGE1) relaxes trabecular smooth muscle by interacting with specific G-protein coupled receptors on human corpus cavernosum smooth muscle and increasing intracellular synthesis of cAMP. Misoprostol (Cytotec), is an oral prostaglandin E analogue. The purpose of this study was to compare the functional activity of misoprostol with PGE1 in human corpus cavernosum and cultured human corpus cavernosum smooth muscle cells. Misoprostol, misoprostol free acid or PGE1 induced dose-dependent relaxations in strips of human corpus cavernosum. At concentrations greater than 10(-6) M, tissue recontraction was observed with all three agents. This was abrogated by pretreatment with the thromboxane A2 receptor antagonist SQ29,548. From these observations, we conclude that misoprostol is activated by human corpus cavernosum in situ and relaxes phenylephrine-precontrated tissue strips in vitro. This relaxation response is mediated by the increased cAMP synthesis by these agents.
前列腺素E1（PGE1）通过与人类海绵体平滑肌上特定的G蛋白偶联受体相互作用并增加细胞内cAMP的合成，从而使小梁平滑肌松弛。米索前列醇（喜克溃）是一种口服前列腺素E类似物。本研究的目的是比较米索前列醇与PGE1在人类海绵体及培养的人类海绵体平滑肌细胞中的功能活性。米索前列醇、米索前列醇游离酸或PGE1在人类海绵体条带中诱导剂量依赖性松弛。在浓度大于10^(-6) M时，观察到这三种药物均会引起组织再收缩。血栓素A2受体拮抗剂SQ29,548预处理可消除这种现象。基于这些观察结果，我们得出结论：米索前列醇在人体内被海绵体原位激活，并在体外使苯肾上腺素预收缩的组织条带松弛。这种松弛反应是由这些药物增加cAMP合成介导的。
