本文用离体培养胎盘滋养层细胞的方法,观察酪氨酸、苏氨酸和丝氨酸对滋养层细胞孕酮分泌的影响。结果表明,这3种氨基酸均能不同程度地抑制滋养层细胞孕酮分泌。另外还观察到,它们对滋养层细胞3β-类固醇脱氢酶活性有抑制作用。从而提示,它们对3β-类固醇脱氢酶的抑制可能是降低孕酮分泌的途径之一。 In this paper, the method of culturing placental trophoblast cells in vitro was used to observe the effect of tyrosine, threonine and serine on progesterone secretion in trophoblast cells. The results showed that all three amino acids inhibited the secretion of progesterone in trophoblast cells to varying degrees. It has also been observed that they inhibit the trophoblast 3β-steroid dehydrogenase activity. It is suggested that their inhibition of 3β-steroid dehydrogenase may be one of the ways to reduce progesterone secretion.