Protection of islets of Langerhans from interleukin-1 toxicity by artificial membranes.
Recently it has been reported that interleukin 1 may play a central role in the immune destruction of islets. Since the mass weight of interleukin-1 is close to that of insulin, destruction of transplanted islets may be possible although they are enclosed in membranes that prevent penetration by immune-competent cells and cyto-toxic antibodies. The present in vitro study showed that the encapsulated rat islets are protected from high doses of IL-1 (1000 ng) inside a hollow fiber membrane with a cutoff of 50,000 D. The function of islets in a free-floating culture, however, was suppressed in a dose-dependent manner (1000 ng/L; 20-30% of controls). Histologically, no damage of the free-floating or encapsulated islets was observed at 1000 ng of IL-1-containing medium. Islets washed out of the devices after 2 days of exposure to IL-1 showed no difference in glucose-stimulated insulin release when compared with islets not exposed that were kept in free-floating culture. It is suggested that an unspecific coating of the membranes by serum proteins (containing physiological IL-1 antagonists) may cause the protective effect.
Medizinische Klinik III, Justus Liebig Universitaet, Giessen, West Germany.
T
T
Zekorn
U
U
Siebers
R G
RG
Bretzel
M
M
Renardy
H
H
Planck
P
P
Zschocke
K
K
Federlin
D000818:Animals; D002463:Cell Membrane Permeability / Q000187:drug effects; D046508:Culture Techniques; D005947:Glucose / Q000502:physiology; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D007375:Interleukin-1 / Q000633:toxicity*; D007515:Islets of Langerhans / Q000276:immunology*; D008297:Male; D008567:Membranes, Artificial; D008970:Molecular Weight; D051381:Rats; D011917:Rats, Inbred Lew
D007328:Insulin; D007375:Interleukin-1; D008567:Membranes, Artificial; D005947:Glucose