title: The proliferation-inhibiting effect of endotoxin on human endothelial cells in culture and its possible implication in states of shock.
abstract: The aim of this study was to determine whether bacterial endotoxin (LPS) could be responsible for the in vitro endothelial proliferation-inhibiting activity found in some serum samples derived from patients suffering from "sepsis" or "shock." DNA-synthesis response of cultured human endothelial cells was measured by autoradiographic methods. We found a dose-dependent decrease in the proliferation-inducing capacity of human serum after the addition of endotoxin without any detectable cellular injury. This effect depended on the serum concentration in the culture medium: higher serum concentrations reduced the measurable LPS-activity. The endotoxin effect turned out to be preventable when LPS sera were preincubated with different concentrations of Polymyxin B sulphate. That treatment also seemed to prevent the inhibiting effect of some patient sera. The inhibiting effect of both the LPS-serum and the patient serum could be reversed by washing and adding fresh human serum. We conclude that the endothelial regeneration-inhibiting activity of endotoxin may play an important role in the irreversibility of certain shock states.
mesh_terms: D001345:Autoradiography; D046508:Culture Techniques; D004305:Dose-Response Relationship, Drug; D004727:Endothelium / Q000187:drug effects; D004731:Endotoxins / Q000494:pharmacology*; D006801:Humans; D008938:Mitosis / Q000187:drug effects*; D011112:Polymyxin B / Q000494:pharmacology; D012475:Salmonella; D012772:Shock, Septic / Q000097:blood*; D013936:Thymidine / Q000378:metabolism; D014471:Umbilical Veins / Q000187:drug effects*
chemical_list: D004731:Endotoxins; D011112:Polymyxin B; D013936:Thymidine