Journal article
Effect of age on in vitro triazolam biotransformation in male human liver microsomes
The Journal of pharmacology and experimental therapeutics, Vol.308(3), pp.874-879
03/2004
Handle:
https://hdl.handle.net/2376/110541
PMID: 14634046
Abstract
We studied age-related changes in enzyme kinetic parameters in human liver microsomes (HLMs) in vitro, using triazolam (TRZ), an index of CYP3A activity. HLMs were prepared from male livers from four age groups, n = 5 per group: A (14-20 years), B (21-40 years), C (41-60 years), and D (61-72 years). Mean V(max) values in groups B and C for both 1-hydroxytriazolam (1-OH-TRZ) and 4-hydroxy-triazolam (4-OH-TRZ) formation were significantly greater as compared with groups A and D individually, as well as the net intrinsic clearance (sum of the two pathways). The mean net intrinsic clearance (Cl(int)) values were 25.2, 89.8, 78, and 20.6 nl/min/mg protein in A, B, C, and D, respectively. TRZ Cl(int) correlated well with total CYP3A content (r(s) = 0.84; P < 0.0001). Testosterone (TST) inhibited 1-OH-TRZ formation and activated 4-OH-TRZ formation in all age groups, with no significant differences among the groups; this suggests that the drug-drug interaction potential using TRZ and TST as index CYP3A substrates may not change with age. Reduced V(max) and Cl(int) for TRZ hydroxylation and CYP3A protein in livers from elderly men suggest reduced CYP3A gene expression in this group.
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Details
- Title
- Effect of age on in vitro triazolam biotransformation in male human liver microsomes
- Creators
- Kiran C Patki - Department of Pharmacology and Experimental Therapeutics, Tufts University School of Medicine, Boston, MA 02111, USALisa L von MoltkeJerold S HarmatzLeah M HesseMichael H CourtDavid J Greenblatt
- Publication Details
- The Journal of pharmacology and experimental therapeutics, Vol.308(3), pp.874-879
- Academic Unit
- Veterinary Clinical Sciences, Department of
- Publisher
- United States
- Grant note
- DA-13834 / NIDA NIH HHS DK-58496 / NIDDK NIH HHS GM-61834 / NIGMS NIH HHS DA-05258 / NIDA NIH HHS AG-17880 / NIA NIH HHS MH-01237 / NIMH NIH HHS RR-00054 / NCRR NIH HHS DA-13209 / NIDA NIH HHS MH-58435 / NIMH NIH HHS
- Identifiers
- 99900546923101842
- Language
- English
- Resource Type
- Journal article