Detection of cell apoptosis
Apoptosis of liver and intestine cells was detected by terminal
deoxynucleotidyl. Transferase dUTP nick-end labeling assay (TUNEL) with
the In-Situ Cell Death Detection kit (Roche, Basel, Switzerland)
according to the kit instructions. Briefly, the cells on coverslips were
washed with PBS and fixed with 4% paraformaldehyde for 15 min at room
temperature. After washing, the cells were incubated in permeabilization
solution (0.1% Triton X-100 in 0.1% sodium citrate, freshly prepared)
for 2 min on ice. The cells were then incubated with the TUNEL reaction
mixture in a humidified chamber at 37°C for 1 h. Subsequently, the cells
were briefly rinsed with PBS and counterstained with DAPI for 5 min in
order to visualize the nuclei.