Selective regulation of voltage‐gated potassium channel subunits in presympathetic PVN neurons of rats with myocardial infarction (686.9)

Abstract

Hypothalamic paraventricular nucleus (PVN) neurons contain presympathetic neurons that project to the rostral ventrolateral medulla (RVLM; PVN‐RVLM neurons) and control cardiovascular sympathetic tones. In this neuronal population, cardiovascular disorders such as hypertension modulate voltage‐gated potassium (Kv) channels, but under myocardial infarction (MI), modulation of Kv channels has not been extensively studied. In the present study, we investigated differences in mRNA expressions of the Kv channel subunits in PVN‐RVLM neurons between sham and MI rats, using single‐cell real‐time RT‐PCR. The results showed that the mRNA level of Kv4.2 was significantly up‐regulated after MI, and this regulation was exclusively found in the dorsal cap subdivision. There was no change in Kv4.3 mRNA level between sham and MI rats in any of the subdivisions. These results suggest that heterogeneous cell populations exist in each subdivision of PVN‐RVLM neurons and that MI selectively regulates the mRNA levels of Kv4.2 in PVN‐RVLM neurons distributed in the dorsal cap subdivision.Grant Funding Source: Supported by the National Research Foundation of Korea (2010‐0015531)