Referenced in: none

Automatically associated channels: Kir6.1 , Kir6.2

Title: Properties and functions of KATP during mouse perinatal development.

Authors: Li Nie, Ming Tang, Ying Zeng, Huaping Jiang, Hangchuan Shi, Hongyan Luo, Xinwu Hu, Linlin Gao, Jiaoya Xi, Aifen Liu, Michael Reppel, Jürgen Hescheler, Huamin Liang

Journal, date & volume: Biochem. Biophys. Res. Commun., 2012 Feb 3 , 418, 74-80

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/22252295

Abstract
Prevailing data suggest that ATP-sensitive potassium channels (K(ATP)) contribute to a surprising resistance to hypoxia in mammalian embryos, thus we aimed to characterize the developmental changes of K(ATP) channels in murine fetal ventricular cardiomyocytes.Patch clamp was applied to investigate the functions of K(ATP). RT-PCR, Western blot were used to further characterize the molecular properties of K(ATP) channels.Similar K(ATP) current density was detected in ventricular cardiomyocytes of late development stage (LDS) and early development stage (EDS). Molecular-biological study revealed the upregulation of Kir6.1/SUR2A in membrane and Kir6.2 remained constant during development. Kir6.1, Kir6.2, and SUR1 were detectable in the mitochondria without marked difference between EDS and LDS. Acute hypoxia-ischemia led to cessation of APs in 62.5% of tested EDS cells and no APs cessation was observed in LDS cells. SarcK(ATP) blocker glibenclamide rescued 47% of EDS cells but converted 42.8% of LDS cells to APs cessations under hypoxia-ischemic condition. MitoK(ATP) blocker 5-HD did not significantly influence the response to acute hypoxia-ischemia at either EDS or LDS. In summary, sarcK(ATP) played distinct functional roles under acute hypoxia-ischemic condition in EDS and LDS fetal ventricular cardiomyocytes, with developmental changes in sarcK(ATP) subunits. MitoK(ATP) were not significantly involved in the response of fetal cardiomyocytes to acute hypoxia-ischemia and no developmental changes of K(ATP) subunits were found in mitochondria.