Figure 4.

Blocking beta 2-adrenergic receptor (β₂-AR) increases amyloid beta (Aβ) accumulation in amyloid precursor protein/presenilin 1 double transgenic (AD-TG) mice.

(A) Immunohistochemical staining of the hippocampus was performed 1 day after 5 days of training. The representative images show the levels of plaque load in the hippocampus of wild type control (non-TG), AD-TG/NaCl, and AD-TG/NaCl mice given ICI 118551 (AD-TG/ICI) immunostained with Aβ antibody under a light microscope. Results showed that ICI treatment of AD-TG mice increased Aβ accumulation in the hippocampus (indicated by arrow). Scale bars: 100 μm. (B) Quantification of Aβ staining was performed by Image Pro Plus 6.0 software. (C and D) The levels of amyloid beta 40 (Aβ₄₀) and amyloid beta 42 (Aβ₄₂) in hippocampi were detected by enzyme linked immunosorbent assay. *P < 0.05, **P < 0.01, vs. non-TG/NaCl. Data are expressed as the mean ± SD (n = 8, one-way analysis of variance followed by the least significant difference test). Wild type control (non-TG) and AD-TG mice were sub-grouped: saline control group, injections of 0.9% NaCl, termed non-TG/NaCl and AD-TG/NaCl; β₂-AR antagonist treatment group, mice were administered ICI 118551 (1 mg/kg per day, intraperitoneally), termed AD-TG/ICI.