title: The synthesis of 5-alpha-dihydrotestosterone from androgens by human gingival tissues and fibroblasts in culture in response to TGF-beta and PDGF.
abstract: The effects of TGF-beta and PDGF on the metabolic conversion of 14C-testosterone by human gingival tissue (HGT) from 5 subjects was investigated. The metabolic conversions in response to TGF-beta and PDGF were also studied in 4-6 cell-lines of cultured gingival fibroblasts, using 14C-testosterone and 14C-4-androstenedione as substrates. Duplicate incubations of HGT were performed in Eagle's MEM + 10% FCS and optimal stimulatory concentrations of TGF-beta/PDGF for 24 h. Similar incubations were performed in duplicate with cell-lines of cultured gingival fibroblasts, TGF-beta/PDGF, 14C-testosterone/14C-4-androstenedione in Eagle's MEM + 10% FCS. The radioactive metabolites were extracted, separated and quantified. With HGT, TGF-beta and PDGF caused 2.5/2-fold increases in DHT synthesis (p < 0.1; Wilcoxon signed rank test) and 3.4/2-fold increases in 4-androstenedione formation (p < 0.1) from 14C-testosterone. PDGF increased DHT and testosterone synthesis from 14C-4-androstenedione by 3-fold in gingivae (p < 0.1). With cell-lines, average values of duplicate incubations showed 2.8/2-fold increases in DHT synthesis from 14C-testosterone in response to TGF-beta/PDGF (p < 0.1; p < 0.2) and 2.4/2-fold increases in 4-androstenedione synthesis (p < 0.1; p < 0.2). With 14C-4-androstenedione as substrate, TGF-beta/PDGF caused 1.6/1.9-fold increases in DHT synthesis compared with controls (p < 0.05; p < 0.1) and 1.7/1.5-fold increases in testosterone formation from this substrate (p < 0.05; p < 0.1). Due to the strong implications of TGF-beta/PDGF and anabolic androgens on matrix repair, significant increases in DHT synthesis from 2 androgenic substrates in response to TGF-beta and PDGF are of particular relevance to inflammatory repair processes.
authors.affiliation: Department of Periodontology, King's College School of Medicine & Dentistry, London, UK.
authors.forename: S C
authors.initials: SC
authors.lastname: Kasasa
authors.forename: M
authors.initials: M
authors.lastname: Soory
mesh_terms: D000328:Adult; D000728:Androgens / Q000378:metabolism*; D000735:Androstenedione / Q000378:metabolism; D002478:Cells, Cultured / Q000187:drug effects / Q000378:metabolism; D013196:Dihydrotestosterone / Q000378:metabolism*; D016326:Extracellular Matrix Proteins / Q000096:biosynthesis; D005260:Female; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D008401:Gas Chromatography-Mass Spectrometry; D005881:Gingiva / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D005891:Gingivitis / Q000378:metabolism*; D006801:Humans; D008297:Male; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology* / Q000502:physiology; D012038:Regeneration / Q000187:drug effects* / Q000502:physiology*; D018709:Statistics, Nonparametric; D013739:Testosterone / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000494:pharmacology* / Q000502:physiology; D015854:Up-Regulation
chemical_list: D000728:Androgens; D016326:Extracellular Matrix Proteins; D010982:Platelet-Derived Growth Factor; D016212:Transforming Growth Factor beta; D013196:Dihydrotestosterone; D013739:Testosterone; D000735:Androstenedione