title: [Effects of tyrosine alone and tyrosine in combination with RU486 on early pregnancy in mice and the mechanism of action].
abstract: Treatment with tyrosine at the dosage of 85 mg.kg-1 on day 6-8 of gestation did not have significant effect to terminate early pregnancy in mice. Tyrosine combined with RU486 was shown to have a synergistic effect to terminate early pregnancy. Tyrosine 170 mg.kg-1 on day 6-10 of gestation significantly decreased the concentration of serum progesterone in early pregnant mice. Further study with luteal cells in rats showed that tyrosine 50 micrograms.ml-1 inhibited hCG-induced progesterone production when used alone, and inhibited basal production when used together with (+) PG05. These results suggest that the inhibiting effect of tyrosine on steroidogenesis may contribute to the termination of early pregnancy.
authors.affiliation: Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050.
authors.forename: H
authors.initials: H
authors.lastname: Duan
authors.forename: N G
authors.initials: NG
authors.lastname: Wang
mesh_terms: D000021:Abortifacient Agents, Steroidal / Q000494:pharmacology*; D000818:Animals; D002478:Cells, Cultured; D003338:Corpus Luteum / Q000166:cytology / Q000378:metabolism*; D005260:Female; D051379:Mice; D015735:Mifepristone / Q000494:pharmacology*; D011247:Pregnancy; D011374:Progesterone / Q000096:biosynthesis* / Q000097:blood; D051381:Rats; D014443:Tyrosine / Q000494:pharmacology*
chemical_list: D000021:Abortifacient Agents, Steroidal; D015735:Mifepristone; D014443:Tyrosine; D011374:Progesterone