Review article Tocolytic therapy in obstetrics

premature or excessive uterine activity [38], Other terms, such äs "sedation of the irritated myometrium " or "relaxation of the uterus " have the same meaning; they are, however, not commonly applied [10, 11, 17, 29]. At the beginning of the research for new sub-stances with inhibitory effect on the uterus it was postulated that progesterone or newly-developed gestagen preparations could inhibit uterine activity. In vitro äs well äs in vivo ex-periments showed that progesterone, in con-centrations present during pregnancy [37, 56], exerts a synergistic effect on oxytocin and in-creases uterine activity. High concentrations which should be applied exclusively for experimental purposes showed the block inaugurated by CSAPO [18]. Together with estrogen, progesterone increases the metabolic activity of the uterus. Prolonged influence leads to relaxation of the tissue and increased uterine weight. The collagen content äs well äs that of nucleic acids, glycogen, and lipids is raised. The sensitivity to exogenous Irritation, e. g. uterine distension by the growing fetus, or to drugs, e. g. oxytocin, increases. Due to the low solubility in water, the considerable affinity to serum protein, and a half-life of 15 minutes, even the highest possible concentrations of progesterone cannot be expected to exert a sufficient effect on the myometrium [31, 36, 54]. 1. Pharmacology of tocolysis Cinnamedrine was the first ß-adrenergic sub-stance which, äs reported by SCHULTZ in 1940, showed a relaxant effect on the smooth muscle; however, it soon feil into disuse. In 1960 LISH Curriculum vitae KARL HEINZ MOSLER was born in Beuthen, Silesia, o