Abstract
1. Glucuronidation and sulphation of ethinyloestradiol (EE2) was studied in human liver. Microsomal glucuronyltransferase activity was measured in 110 livers whose donors were 71 women and 39 men. Enzyme activity ranged between 12.6 and 242 pmol min-1 mg-1 protein, i.e. over a 19-fold range and the mean (+/- s.d.) glucuronyltransferase activity was 96.8 +/- 47.9 pmol min-1 mg-1 protein. 2. Cytosolic sulphotransferase activity was measured in 138 livers whose donors were 90 women and 48 men. Enzyme activity ranged between 14.4 and 98.2 pmol min-1 mg-1 protein, i.e. over a 7-fold range, and the mean (+/- s.d.) sulphotransferase activity was 43.7 +/- 18.6 pmol min-1 mg-1 protein. 3. Human liver glucuronyltransferase and sulphotransferase activities showed a unimodal distribution pattern. Enzyme activities were neither sex-related nor age-dependent. Sulphotransferase activity did not correlate with glucuronyltransferase activity (n = 80) suggesting that the two enzymes are independently regulated. The ratio of specific glucuronyltransferase to sulphotransferase activity ranged between 0.15 and 8.0 (mean +/- s.d., 2.44 +/- 1.51) and was unimodally distributed.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Evans D. A. N-acetyltransferase. Pharmacol Ther. 1989;42(2):157–234. doi: 10.1016/0163-7258(89)90036-3. [DOI] [PubMed] [Google Scholar]
- Helton E. D., Williams M. C., Goldzieher J. W. Human urinary and liver conjugates of 17alpha-ethnylestradiol. Steroids. 1976 Jun;27(6):851–867. doi: 10.1016/0039-128x(76)90144-6. [DOI] [PubMed] [Google Scholar]
- LOWRY O. H., ROSEBROUGH N. J., FARR A. L., RANDALL R. J. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed] [Google Scholar]
- Löffelholz K., Pappano A. J. The parasympathetic neuroeffector junction of the heart. Pharmacol Rev. 1985 Mar;37(1):1–24. [PubMed] [Google Scholar]
- Orme M. L., Back D. J., Ball S. Interindividual variation in the metabolism of ethynylestradiol. Pharmacol Ther. 1989;43(2):251–260. doi: 10.1016/0163-7258(89)90121-6. [DOI] [PubMed] [Google Scholar]
- Pacifici G. M., Back D. J. Sulphation and glucuronidation of ethinyloestradiol in human liver in vitro. J Steroid Biochem. 1988 Sep;31(3):345–349. doi: 10.1016/0022-4731(88)90360-3. [DOI] [PubMed] [Google Scholar]
- Powis G., Jardine I., Van Dyke R., Weinshilboum R., Moore D., Wilke T., Rhodes W., Nelson R., Benson L., Szumlanski C. Foreign compound metabolism studies with human liver obtained as surgical waste. Relation to donor characteristics and effects of tissue storage. Drug Metab Dispos. 1988 Jul-Aug;16(4):582–589. [PubMed] [Google Scholar]
- Viani A., Temellini A., Tusini G., Pacifici G. M. Human brain sulphotransferase and glucuronyltransferase. Hum Exp Toxicol. 1990 Mar;9(2):65–69. doi: 10.1177/096032719000900201. [DOI] [PubMed] [Google Scholar]
- Weinshilboum R. Methyltransferase pharmacogenetics. Pharmacol Ther. 1989;43(1):77–90. doi: 10.1016/0163-7258(89)90048-x. [DOI] [PubMed] [Google Scholar]