Age-related down-regulation of HCN channels in rat sinoatrial node

作者：Huang, Xin; Yang, Pei; Du, Yuan; Zhang, Junbo; Ma, Aiqun^*

来源：Basic Research in Cardiology, 2007, 102(5): 429-435.

DOI：10.1007/s00395-007-0660-5

• HCN channel
• sinoatrial node
• aging
• heart rate

Aging is associated with deteriorated sinoatrial ( SA) node function. The pacemaker current ( If) carried by hyperpolarization- activated, cyclic nucleotide- gated cation ( HCN) channels plays a key role in the generation of spontaneous activity of the SA node cells. In the present study, the SA node cells were identified and isolated using the laser capture microdissection ( LCM) technique for quantitative analysis of the HCN channel isoforms HCN1- HCN4 transcripts. Using real- time quantitative reverse transcriptionpolymerase chain reaction ( RT- PCR), marked down- regulated transcriptions of HCN2 and HCN4 were observed in the SA node from young ( 1- month- old) to adult ( 4- month- old) and further to aged ( 30month- old) rats. However, neither the HCN1 nor HCN3 transcript was detectable throughout the lifespan of the rat. Consistently, the effect of 2 mM Cs+ to selectively block the HCN channels, on pacemaking was also lessened with age. Our findings raise the possibility that the down- regulated transcription and relative function of HCN channels may contribute to the decline of the SA node function in aged rats.

• 出版日期2007-9
• 单位西安交通大学