The effects of endothelin-1 on human dermal fibroblast growth and synthetic activity.
Endothelin-1 (ET-1) is the most potent vasoconstricting substance known, and is believed to have a fundamental role in the regulation of blood flow. It is a peptide produced and secreted by endothelial cells in response to hypoxia and injury, as well as by macrophages. These properties suggest that ET-1 may play a role during tissue repair. In this study, we have examined the effects of ET-1 on the growth and synthetic activity of human dermal fibroblasts. ET-1 stimulated DNA synthesis in serum-deprived cultures: this effect reached a mean value of 64% more than control (P < 0.01) at 2.5 ng/ml (10(-9) M) of ET-1. In contrast, the addition of ET-1 to fibroblasts at different densities and in 0, 3, or 10% fetal bovine serum (FBS) failed to increase cell counts. In 1% FBS, a 41% mean increase in cell counts compared to control values was observed in cultures treated with 2.5 ng/ml of ET-1 (P < 0.01). Incubation of dermal fibroblast cultures at 37 degrees C for 1 hr with increasing concentrations of 125I-ET-1 resulted in saturable binding and a half-maximal specific binding of 27.5 pM. Scatchard plot analysis of the binding showed a Kd of 224 pM and 11,400 high-affinity binding sites per cell. ET-1 had no effect on [14C]-glucosamine incorporation by fibroblasts and caused no increase in collagen synthesis, as measured by collagenase-sensitive [3H]proline incorporation and by salt precipitation of 3H-labeled collagen at acid and neutral pH successively.(ABSTRACT TRUNCATED AT 250 WORDS)
Falanga
V
V
University of Miami School of Medicine, Department of Dermatology, Florida 33101.
Katz
M H
MH
Kirsner
R
R
Alvarez
A F
AF
D002455:Cell Division; D002478:Cells, Cultured; D003094:Collagen / Q000096:biosynthesis; D004247:DNA / Q000096:biosynthesis; D016232:Endothelins / Q000378:metabolism / Q000494:pharmacology*; D005347:Fibroblasts / Q000166:cytology* / Q000378:metabolism*; D005944:Glucosamine / Q000378:metabolism; D006801:Humans; D011392:Proline / Q000378:metabolism; D017466:Receptors, Endothelin / Q000378:metabolism; D012867:Skin
D016232:Endothelins; D017466:Receptors, Endothelin; D003094:Collagen; D004247:DNA; D011392:Proline; D005944:Glucosamine