Abstract: Abstract Objective: To explore abnormal expression of G protein in the cortex and hippocampus of 8-old-month and 18-old-month senescence-accelerated prone mouse(SAMP8). Methods: senescence-accelerated mice resistant 1(SAMR1) as control mice, Detection of Gαq/11, Gαi and GαS protein abnormal expression in 8-month-old and 18-month-old SAMP8 by using Western-blot method. Results: Compared with the month-old SAMR1, expression of GαS, Gαi and Gαq protein in 8-month-old SAMP8 cortex and hippocampus were not different (p> 0.05). Gαq expression in 18-months-old SAMP8 cortex was significantly lower than that of SAMR1 (p <0.05). Gαq and Gαi expression in 18-months-old SAMP8 hippocampus was significantly lower than SAMR1(p <0.05). Conclusion: Abnormal expression of Gαq and Gαi in 18-month-old SAMP8 brain involved in Alzheimer Disease (Alzheimer's, AD) pathological progress and is expected to be a target for AD treatment.

Key words: G protein, SAMP8, Alzheimer disease, Western-blot