• Journal of Embryo Transfer
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• v.22 no.3
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• pp.149-154
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• 2007

Endometrial cells play important roles in implantation and during pregnancy. This study was carried out to identify whether two-pore domain $K^+\;(K_{2P})$ channels are expressed in endometrial cells of Korean cattle. $K_{2P}$ channels set the resting membrane potential of many kinds of neuronal cells in the central and peripheral nervous systems. RT-PCR data showed that TASK-1, TASK-3, TREK-1, TREK-2, and TRAAK were expressed in bovine endometrial cells, and the mRNA expression levels were similar between endometrial cells with or without endometritis. The protein expression was confirmed by using commercially available polyclonal antibodies (TASK-3, TREK-1, TREK-2, and TRAAK). TASK-3 and TREK-1 were expressed in all area of endometrial cells including nuclei, while TREK-2 and TRAAK were expressed in all area of cells except nuclei. These results demonstrate for the first time the presence of $K_{2P}$ channel in endometrial cells of Korean cattle.

• The Korean Journal of Physiology and Pharmacology
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• v.9 no.1
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• pp.63-68
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• 2005

Hydrogen peroxide ($H_2O_2$) causes oxidative stress and is considered as an inducer of cell death in various tissues. Two-pore domain $K^+$ ($K_{2p}$) channels may mediate $K^+$ efflux during apoptotic volume decreases (AVD) in zygotes and in mouse embryos. In the present study, we sought to elucidate linkage between $K_{2p}$ channels and cell death by $H_2O_2$. Thus $K_{2p}$ channels (TASK-1, TASK-3, TREK-1, TREK-2) were stably transfected in HEK-293 cells, and cytotoxicity assay was preformed using cell counting kit-8 (CCK-8). Cell survival rates were calculated using the cytotoxicity assay data and dose-response curve was fitted to the $H_2O_2$ concentration. Ionic currents were recorded in cell-attached mode. The bath solution was the normal Ringer solution and the pipette solution was high $K^+$ solution. In HEK-293 cells expressing TREK-1, TREK-2, TASK-3, $H_2O_2$ induced cell death did not change in comparison to non-transfected HEK-293. In HEK-293 cells expressing TASK-1, however, dose-response curve was significantly shifted to the left. It means that $H_2O_2$ induced cell death was increased. In cell attached-mode recording, application of $H_2O_2$ (300μM) increased activity of all $K_{2p}$ channels. However, a low concentration of $H_2O_2$ ($50{\mu}M$) increased only TASK-1 channel activity. These results indicate that TASK-1 might participate in $K^+$ efflux by $H_2O_2$ at low concentration, thereby inducing AVD.