title: Changes in urinary homocysteine following synthetic steroidal estrogen and progestogen administration to rats.
abstract: The present work involved the administration of both ethynyl estradiol and levonorgestrel to groups of rats, followed by determination of the homocysteine excretion rate in urine. The results indicate that a statistically significant difference exists between the excreted levels of homocysteine in the urine of both control and levonorgestrel-treated rats and the levels shown by rats treated with ethynyl estradiol. The implications of these results are discussed, especially with respect to observations which indicate that homocysteine may be a precipitating factor in the development of thrombosis. Also included in this paper is a study which confirms the identity of the HPLC peak as being homocysteine by forming a radioactive derivative of this particular sulphydryl-containing amino acid, and then analysing the resulting mixture by TLC.
mesh_terms: D000818:Animals; D002855:Chromatography, Thin Layer; D004347:Drug Interactions; D004997:Ethinyl Estradiol / Q000494:pharmacology*; D005260:Female; D006710:Homocysteine / Q000652:urine*; D007700:Kinetics; D016912:Levonorgestrel; D009644:Norgestrel / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013237:Stereoisomerism
chemical_list: D006710:Homocysteine; D009644:Norgestrel; D004997:Ethinyl Estradiol; D016912:Levonorgestrel