Effects of 9-deoxo-16, 16-dimethyl-9-methylene PGE2 on muscle contractile activity and collagen synthesis in the human cervix

The in vitro effects of a stable PGE-analogue (9-deoxo-16, 16-dimethyl-9-methylene PGE₂ (9-methylene PGE₂) on human cervical tissue was investigated. The influence of the analogue on collagen biosynthesis was studied by measuring the incorporation of ³H-proline, while smooth muscle effects were evaluated by isometric recording of contractile activity. The specimens were obtained by needle biopsy from women in early and late pregnancy and from nonpregnant women of fertile age.9-methylene PGE₂ compared with controls increased the incorporation of ³H-proline in the secretory phase and before the 9th week of pregnancy, whereas radiolabelling was decreased in the follicular phase, in the 9th–12th week and at term. With respect to incorporation of 3-H-proline, 9-methylene PGE₂ was equipotent to PGE₂. 9-methylene PGE₂ inhibited spontaneous contractile activity in early as well as in late pregnancy but increased muscular activity in nonpregnant patients. The inhibitory effects of the analogue was similar to that of PGE₂ but the natural compound was considerably more potent in this respect.