title: Regulation of endothelin release from human brain microvessel endothelial cells.
abstract: After approval by the Local Ethical Committee, brain microvessel endothelial cells from human cadavers were isolated by enzymatic digestion and gradient centrifugation. Basal levels of endothelin-1 (ET) in the supernatant increased over time (3 h, 18.3 +/- 4.3 pg/ml; 6 h, 31.3 +/- 1.1 pg/ml; 24 h, 88.0 +/- 5.7 pg/ml; 48 h, 86.3 +/- 11.2 pg/ml, mean +/- SD). Tumor necrosis factor-alpha (TNF-alpha) (270 U/ml) increased ET concentration dose-dependently: 3 h, 190 +/- 70%; 24 h, 217 +/- 39%; 48 h, 207 +/- 5%; TNF-alpha at 210 U/ml: 3 h, 137%; 24 h, 170%; 48 h, 212% (values are relative changes from control, run in parallel to the stimulated wells). Interleukin-1 alpha (IL-1 alpha) (38.8 U/ml) also increased ET dose-dependently: (3 h, 129%; 24 h, 161%; 48 h, 212%; IL-1 alpha 1.4 U/ml: 3 h, 116%; 24 h, 122%; 48 h, 180%). Lipoprotein (a) (Lp(a)) had a dual effect on ET, increasing ET in the first 3 h but reducing it by the end of the 48-h observation period. This effect was not dose-dependent in the concentration range tested: Lp(a) 450 micrograms/ml; 3 h, 188%; 24 h, 91%; 48 h, 85%; Lp(a) 360 micrograms/ml: 3 h, 180%; 24 h, 94%; 48 h, 52%). Lp(a) reduced the stimulatory effect of cytokines on ET release. Maximal values at 48 h were TNF-alpha 207%, TNF-alpha + Lp(a) 91%, IL-1 alpha 212%, IL-1 alpha + Lp(a) 64%. In HPLC analysis, the total ET-like immunoreactivity co-eluted with the synthetic human ET standard. A cell culture of human brain microvessel endothelial cells was established. TNF-alpha and IL-1 alpha increased ET secretion, whereas Lp(a) had a dual effect. When given together, Lp(a) reduced the effect of cytokines on ETs.
authors.affiliation: National Stroke Center, Semmelweis University, Budapest, Hungary.
authors.forename: J
authors.initials: J
authors.lastname: Skopál
authors.forename: P
authors.initials: P
authors.lastname: Turbucz
authors.forename: M
authors.initials: M
authors.lastname: Vastag
authors.forename: Z
authors.initials: Z
authors.lastname: Bori
authors.forename: M
authors.initials: M
authors.lastname: Pék
authors.forename: R
authors.initials: R
authors.lastname: deChâtel
authors.forename: Z
authors.initials: Z
authors.lastname: Nagy
authors.forename: M
authors.initials: M
authors.lastname: Tóth
authors.forename: I
authors.initials: I
authors.lastname: Karádi
mesh_terms: D001923:Brain Chemistry / Q000502:physiology*; D002196:Capillaries / Q000166:cytology / Q000378:metabolism; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D016207:Cytokines / Q000494:pharmacology; D016232:Endothelins / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology; D017270:Lipoprotein(a) / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: D016207:Cytokines; D016232:Endothelins; D007375:Interleukin-1; D017270:Lipoprotein(a); D014409:Tumor Necrosis Factor-alpha