Androstenedione metabolism in human lung fibroblasts.
Human lung fibroblasts in culture metabolized [3H]androstenedione to a number of different compounds, including testosterone, 5 alpha-androstanedione, androsterone, 5 alpha-dihydrotestosterone, isoandrosterone, and 5 alpha-androstane-3 alpha,-17 beta-diol. The major products were 5 alpha-androstanedione and testosterone. Estrone, estradiol-17 beta and 5 beta-reduced steroids were not formed. The production rates of testosterone and 5 alpha-androstanedione from [3H]androstenedione by lung fibroblasts were studied both as a function of incubation time and substrate concentration. The rates of formation of testosterone and 5 alpha-androstanedione remained linear with time up to 4 h. The apparent Km of human lung fibroblast 5 alpha-reductase was 1 microM, and that of 17 beta-hydroxysteroid oxidoreductase was 11 microM. The findings of this study suggest that mesenchyma may contribute to the metabolism of androstenedione in human lung tissue.
Milewich
L
L
Kaimal
V
V
Shaw
C B
CB
Johnson
A R
AR
D000735:Androstenedione / Q000378:metabolism*; D002855:Chromatography, Thin Layer; D005347:Fibroblasts / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D008168:Lung / Q000378:metabolism*; D009924:Organ Culture Techniques; D014316:Tritium
D014316:Tritium; D000735:Androstenedione