Objective To investigate the expression of amyloid beta precursor-like protein 1 （APLP 1） gene on the transcription level in hippocampus of pilocarpine-induced epileptic rats. Methods Epileptic rats were developed by LiCl （3 mmol/kg, i.p.） approximately 20 h prior to pilocarpine （30 mg/kg, i.p.） administration. The 3＇ end partial sequence of rat APLP1 gene was cloned, and the expression levels of APLP1 mRNA in hippocampus of epileptic rats at 6 h, 30 h, 7 d and 15 d were determined by semi-quantitative RT-PCR. Results The 3＇ end partial sequence of rat APLP1 gene shared a 97% homology with that of mice, and 90% with that of human. The APLP1 amino acid sequence of rat was identical with that of mouse, but was different from that of human in 3 residues. Moreover, pilocarpine induced a significant down-regulation ofAPLP1 mRNA expression at 6 h after epilepsy initiation （P 〈 0.05）, and at 30 h, this down-regulation became more dramatic （P 〈 0.01）, which lasted till day 15 （P 〈 0.01）. Conclusion The 3＇ end ofAPLP1 gene is highly conserved, and APLP1 mRNA expression is kept at low level in hippocampus of pilocarpine-induced epileptic rats.
