In Vivo Intestinal Permeability Assay

Mice were orally exposed to acrolein (or water as control) as described above. Three hours after the last gavage, mice were orally given fluorescein isothiocyanate–dextran with average molecular weight of 3000 to 5000 Da (FD-4; Sigma-Aldrich) in saline (500 mg/kg body weight, 125 mg/mL).²¹ After 3 hours, animals were euthanized, and serum was isolated. The serum was analyzed for FD-4 concentration using a fluorescence spectrophotometer at an excitation wavelength of 485 nm and an emission wavelength of 530 nm.