Diabetes, Vol 49, Issue 9 1451-1458, Copyright © 2000 by American Diabetes Association
Altered cytokine and nitric oxide secretion in vitro by macrophages from diabetic type II-like db/db mice
SN Zykova, TG Jenssen, M Berdal, R Olsen, R Myklebust and R Seljelid
Institute of Medical Biology, University of Tromso, Norway. svetlana@fagmed.uit.no
Macrophage dysfunction is a likely mechanism underlying common diabetic
complications such as increased susceptibility to infection, accelerated
atherosclerosis, and disturbed wound healing. There are no available
studies on the function of tissue macrophages in diabetes in humans. We
have therefore studied peritoneal macrophages from diabetic type 2-like
db/db mice. We found that the release of tumor necrosis factor-alpha and
interleukin-1beta from lipopolysaccharide plus interferon-gamma-stimulated
macrophages and vascular endothelial growth factor from both stimulated and
nonstimulated macrophages was significantly reduced in diabetic animals
compared with nondiabetic controls. Nitric oxide production from the
stimulated db/db macrophages was significantly higher than that in the db/+
cultures, whereas there was no difference in their ability to generate
reactive oxygen species. When studied both at light and electron
microscopic levels, macrophages in diabetic animals had an altered
morphological appearance compared with those of normal controls. We
conclude that the function and morphology of the macrophages are disturbed
in db/db mice and that this disturbance is related to the mechanisms
underlying common inflammatory and degenerative manifestations in diabetes.