Effects of chronic exposure to beta-amyloid-peptide25-35 on the mRNA expressions of voltage-gated outward potassium channel subunits in cultured rat hippocampal neurons / 药学学报

ABSTRACT

<p><b>AIM</b>To investigate mRNA expression changes of voltage-gated outward potassium channel subtypes in cultured rat hippocampal neurons after chronic exposure to beta-amyloid-petitde25-35 (beta-AP25-35).</p><p><b>METHODS</b>mRNA expression was detected by RT-PCR, comparative expression levels were determined by imaging densitometer.</p><p><b>RESULTS</b>Delayed rectifying (Kv2.1, Kv1.5), transient outward (Kv1.4, Kv4.2) and large conductance calcium-activated (rSlo) potassium channel mRNA were expressed in cultured rat hippocampal. In the presence of beta-AP25-35 3 mumol.L-1 for 24 h, the relative expression level of Kv2.1 was significantly increased (n = 3, P < 0.05); the other subtypes were not changed obviously (n = 3, P > 0.05). The increase of Kv2.1 mRNA mainly happened between 24 and 36 h after exposure to beta-AP25-35. After exposure to beta-AP25-35 for 60 h, Kv2.1 mRNA decreased significantly (n = 3, P < 0.01).</p><p><b>CONCLUSION</b>The upregulation of Kv2.1 on transcription levels may be involved in the enhancement of delayed rectifying outward potassium (Ik) current induced by beta-AP25-35.</p>