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Updated: Jul 29, 2026
Intravitreal Injection and Quantitation of Infection Parameters in a Mouse Model of Bacterial Endophthalmitis
Published on: February 6, 2021
Vasoactive intestinal peptide (VIP) exacerbates endotoxin-induced uveitis (EIU) in mice
1Laboratory of Immunology, National Eye Institute, NIH, Bethesda, Maryland, United States of America. zhangm@intra.nei.nih.gov
Purpose:
We have previously shown that inhibition of the proinflammatory cytokine tumor necrosis factor- (TNF)-alpha exacerbates the inflammatory process of EIU. To further examine this paradoxic phenomenon, we investigated here the effect on EIU of VIP, a neuropeptide that inbibits TNF-alpha production.
Methods:
VIP was injected concurrently with endotoxin at doses that induce EIU or lethality in mice. Severity of EIU was measured by counting infiltrating cells in eye sections, at 1 or 5 days post endotoxin injection. Survival of mice was monitored periodically, while serum levels of TNF-alpha, interleukin-(IL)-1beta and IL-10 were determined by caputure ELISA.
Results:
Treatment with VIP exacerbated EIU but provided partial protection from the lethal endotoxin effect. VIP treatment also reduced serum levels of TNF-alpha and IL-1beta, but increased levels of IL-10.
Conclusion:
This study further established the paradoxical observation that EIU is exacerbated by lowering the levels of circulating pro-inflammatory cytokines, in particular TNF-alpha.
