Functional measurements
Urothelial barrier function was measured using transepithelial
electrical resistance (TEER) (EVOM2 Epithelial Voltohmmeter (World
Precision Measurements, Sarasota, Florida) on differentiated porcine
urothelial cells. When the TEER reached a value of at least 500
Ω.cm2, which corresponds to a tight epithelium,
samples were included for experiments. [14] A chronic inflammation
model was created by exposing the samples to protamine treatments for
three consecutive days. Samples (n=12) were treated with protamine
sulfate 1400IE/mL (4h) followed by CS 0.2% treatment (1h) and other
samples (n=12) with protamine sulfate only. After treatments, culture
medium was placed in all samples. Baseline TEER was measured right after
this (T=0) and at 7 hours (T=7). This protocol was repeated for three
consecutive days. See figure 1.