Cytotoxic action of IL-1 beta against pancreatic islets is mediated via nitric oxide formation and is inhibited by NG-monomethyl-L-arginine.
IL-1 beta has been previously shown to act as a cytotoxic agent in islets. Here we show by electron microscopy of alginate encapsulated islets, that islet cell lysis is induced by culturing islets for 24 or 48 h in the presence of IL-1 beta. The extent of lysis depends on the IL-1 beta concentration and is slightly enhanced by the addition of TNF-alpha. Cells can be protected from lysis by NG-monomethyl-L-arginine. Lysis is paralleled by an increase in nitrite concentration in culture supernatants of whole islets but not in supernatants of isolated endocrine cells. The results indicate that IL-1 beta toxicity occurs via inducing in non-endocrine islet cells the synthesis and release of nitric oxide, which has been shown earlier to be highly toxic for islet cells.
Bergmann
L
L
Abteilung für Immunbiologie, Medizinische Einrichtungen, Heinrich-Heine-Universität, Düsseldorf, Germany.
Kröncke
K D
KD
Suschek
C
C
Kolb
H
H
Kolb-Bachofern
V
V
D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives* / Q000494:pharmacology; D002478:Cells, Cultured; D007375:Interleukin-1 / Q000037:antagonists & inhibitors / Q000633:toxicity*; D007515:Islets of Langerhans / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D009569:Nitric Oxide / Q000378:metabolism*; D051381:Rats; D011917:Rats, Inbred Lew; D019323:omega-N-Methylarginine
D007375:Interleukin-1; D019323:omega-N-Methylarginine; D009569:Nitric Oxide; D001120:Arginine