Reed M J, Ross M S, Lai L C, Ghilchik M W, James V H
Department of Chemical Pathology, St Mary's Hospital Medical School, London, England.
J Steroid Biochem Mol Biol. 1990 Oct;37(2):301-3. doi: 10.1016/0960-0760(90)90342-i.
The extent to which norethisterone is converted to ethynyloestradiol is controversial. To investigate the conversion of norethisterone to ethynyloestradiol we have used a double isotope infusion technique to measure the conversion in vivo. The use of acids or bases was precluded to prevent possible artefactual formation of phenolic metabolites of norethisterone. Transfer constants for the conversion of norethisterone to ethynyloestradiol in two perimenopausal women were 2.26 and 2.34% as measured in blood and 2.27 and 0.38% in urine. Results from this study show that a small but significant proportion of norethisterone is converted to ethynyloestradiol in vivo.
炔诺酮转化为炔雌醇的程度存在争议。为了研究炔诺酮向炔雌醇的转化，我们采用了双同位素输注技术来测量体内的转化情况。为防止炔诺酮酚类代谢产物可能的人为形成，避免使用酸或碱。在两名围绝经期女性中，炔诺酮转化为炔雌醇的转移常数在血液中测得为2.26%和2.34%，在尿液中为2.27%和0.38%。这项研究的结果表明，炔诺酮在体内有一小部分但显著比例会转化为炔雌醇。
