1965 年 85 巻 8 号 p. 703-709
Examinations were made on the antagonism between oxytocin and 64 kinds of amino acids, amines, peptides, and phenolic compounds. It was found that l-thyroxine, triiodo-l-thyronine, l-diiodotyrosylglycine, l-tyrosyltyrosine derivatives, and a few phenolic compounds were antagonistic to the uterus-contracting action of oxytocin, vasopressin, serotonin, and urinary oxytocic substance when examined by the excised rat uterus, and that pretreatment with these compounds and thyroidectomy increased the wave height of contraction and the amount required for antagonism. When using excised uterus of a guinea pig, thyroxine was antagonistic but not diiodotyrosylglycine or tyrosine ethyl ester, and the contraction was effected by 2, 4-dinitrophenol, all indicating difference according to animal species. Thyroxine was found to antagonize the anaphylaxie contraction of guinea pig uterus. Examination was also made on the antagonistic action with serotonin, using the ileum of a rat and a guinea pig, and it was found that phenolic compounds and l-tyrosyltyrosine derivatives were antagonistic with both animals, while thyroxine was antagonistic when using a rat ileum and not with guinea pig ileum. From these facts, it was considered that thyroidal hormone and compounds related to it must be taking some part, in some form, in the contraction mechanism of smooth muscles.