Structural and Functional Analysis of the Small Intestine in Rats After Six-Month-Long Exposure to Multiwalled Carbon Nanotubes

Structural and functional analysis of the small intestinal villi in outbred rats was performed after treatment with multiwalled carbon nanotube suspension in comparison with the effects of fine charcoal suspension. Chronic (6 months) exposure to nanotubes in a concentration of 0.2 mg/liter and, particularly, 0.5 mg/liter induced significant changes in the small intestine manifested in a decrease in the number of villi without changes in the brush border integrity, increase in the number of destructed villi, and appearance of villi with apical necrosis. These abnormalities were not observed after treatment for a shorter period of time (2 months).