Table 2 Serum Aβ₄₀ levels of homozygous and hemizygous APP21 and APP31 lines determined by ELISA. h?: homozygosity status not determined; he:hemizygous; ho: homozygous; SE: Standard error; N: number of rats included in the statistical test; P: P value. All rats in the APP21 line had measurable levels of Aβ₄₀ in serum. The Aβ₄₀ levels were out of range in 10 of 20 rats in the APP31 line.

From: Development of transgenic rats producing human β-amyloid precursor protein as a model for Alzheimer's disease: Transgene and endogenous APP genes are regulated tissue-specifically