Minimum endotoxin concentration causing inflammation in the anterior segment of rabbit eyes.
OBJECTIVE
This was a quantitative study to investigate the minimum endotoxin concentration causing inflammation in the anterior segment of the eye.


METHODS
Endotoxin was injected intracamerally in pigmented rabbits. A quantitative determination of flare and cells in the aqueous was performed using a laser flare-cell photometer, before and until 72 h after the treatment. An area under the curve (AUC) analysis was employed to evaluate the whole inflammatory reaction regarding flare values.


RESULTS
The time course of flare values in each endotoxin group showed a similar pattern with a peak value at 3 h. An AUC corresponding to values for "average +2sigma", 19301.8 in control eyes, was considered the cutoff value. Using this cutoff value and the regression curve in endotoxin-treated groups, the minimum endotoxin concentration causing inflammation regarding flare values was determined to be 0.60 endotoxin units (EU). Cell counts (cells/0.5 mm(3).0.5 s) corresponding to the value "average +2sigma", 6.07 at 24 h, in control eyes was considered to be the cutoff value. The minimum endotoxin concentration regarding cell counts was determined to be 0.23 EU.


CONCLUSIONS
There was a dissociation in response between flare and cells in the aqueous to intracameral endotoxin. The minimum endotoxin concentration causing inflammation ranged between 0.23 and 0.60 EU.
Sakimoto
Akira
A
Department of Ophthalmology, Nihon University School of Medicine, Tokyo, Japan.
Sawa
Mitsuru
M
Oshida
Taiki
T
Sugaya
Satoshi
S
Hirono
Taisuke
T
Ishimori
Akiko
A
D000818:Animals; D000869:Anterior Eye Segment / Q000187:drug effects* / Q000473:pathology; D019540:Area Under Curve; D018916:Blood-Aqueous Barrier / Q000187:drug effects*; D002452:Cell Count; D004731:Endotoxins / Q000008:administration & dosage* / Q000633:toxicity*; D015590:Fluorophotometry; D008070:Lipopolysaccharides / Q000008:administration & dosage / Q000633:toxicity; D011817:Rabbits; D014606:Uveitis, Anterior / Q000139:chemically induced* / Q000175:diagnosis
D004731:Endotoxins; D008070:Lipopolysaccharides; C044101:endotoxin, Escherichia coli