Related Experiment Videos
Cytokine formation within rat glomeruli during experimental endotoxemia
B Fouqueray1, C Philippe, A Herbelin
1INSERM U. 64, Hôpital Tenon, Paris, France.
Summary
Tumor necrosis factor alpha (TNF alpha) is present in rat glomeruli and increases after lipopolysaccharide (LPS) exposure. Interleukin-6 (IL-6) is also induced by LPS, but interleukin-1 (IL-1) is not detected.
Area of Science:
- Nephrology
- Immunology
- Molecular Biology
Background:
- Cytokines like TNF alpha, IL-1, and IL-6 are implicated in endotoxin-induced acute renal failure.
- Local cytokine production is crucial for their function in renal failure.
Purpose of the Study:
- To investigate the temporal expression of cytokines in rat glomeruli following lipopolysaccharide (LPS) administration.
- To determine the direct effects of LPS on glomerular cytokine release.
Main Methods:
- Glomeruli were isolated from normal and LPS-injected rats.
- Cytokine levels (TNF alpha, IL-1, IL-6) were measured using L-929 fibroblast lytic assay, ELISA, and bioassays.
- In vitro LPS challenge was performed on isolated glomeruli.
Main Results:
- Detectable levels of TNF alpha were found in normal rat glomeruli.
- LPS injection led to a transient increase in glomerular TNF alpha release, dose- and time-dependently.
- LPS directly stimulated TNF alpha release from glomerular cells, independent of infiltrating bone marrow-derived cells.
- Glomerular IL-6 production was induced by LPS both in vivo and in vitro.
- No detectable IL-1 activity was observed within 120 minutes post-LPS injection.
Conclusions:
- Glomeruli constitutively express TNF alpha and rapidly release it upon LPS challenge.
- Glomerular IL-6 is upregulated by LPS, suggesting a role in acute renal failure.
- The absence of IL-1 suggests a specific cytokine profile in early LPS-induced glomerular responses.