ABO and Alzheimer disease: While the concentrations of Aβ-o and Aβ1-40 remained at the same concentrations in 6-month-old TgF344-AD rats (Aβ-o; p = 0.5368, Aβ1-40; p = 0.0931), the concentrations of Aβ1-42 significantly increased in TgF344-AD rats from 4 to 6 months of age (p = 0.0022).