1995 Volume 38 Issue 5 Pages 333-339
Vascular endothelium is known to play an important role in cell-mediated immune responses. Venular permeability can be detected in vivo by injecting an animal with colloidal pigment, such as Monastral Blue B (MbB), and increased pancreatic vanular leakage (PVL) demonstrated with M bB was observed in spontaneously diabetic BB/W rats. In this experiment we investigated the relationship between PVL and insulitis in BB/W rats, and assessed the physiological charcateristics of this phenomenon to explore the role of PVL in the development of autoimmune diabetes.(1) In young BB/W rats, PVL was observed prior to insulitis. In older rats with insulitis, the intensity of PVL was closely correlated with the severity of the insulitis.(2) PVL was suppressed by pretreatment with superoxide dismutase and catalase, which removed the hydroxyl radicals.(3) Serum levels of TNF α in BB/W rats were marekedly increased by injection of MbB (basal: 0 U/ml, MbB: 28 ± 8 U/ml).(4) PVL was almost blocked of the first day after injection of macrophage-toxic silica, but was gradually restored and recovered entirely 8 days after the injection Long-term administration of silica to young BB/W rats almost completely prevented PVL and the development of spontaneous diabetes. These findings suggest that PVL may participate in the development of the disease and that macrohages may play an important role in the onset of PVL.
