• Journal of Embryo Transfer
• /
• v.24 no.3
• /
• pp.189-197
• /
• 2009

Two-pore domain $K^+(K_{2P})$ channels contribute to setting the resting membrane potential in excitable and nonexcitable cells. However, the cellular or tissue distribution and function of $K_{2P}$ channels expressed in mammalian germ cells and reproductive organs have not yet been reviewed by researchers. In this review, we focus on expression, localization and expected properties of $K_{2P}$ channels in germ cells and reproductive organs. The $K_{2P}$ channels are expressed in human cytotrophoblast cells, myometrium, placental vascular system, uterine smooth muscle, and pregnant term tissue, suggesting that $K_{2P}$ channels might be involved in the processes of pregnance. The $K_{2P}$ channels are also expressed in mouse zygotes, monkey sperm, ovary, testis, germ cells, and embryos of Korean cattle. Interestingly, $K_{2P}$ channels are modulated by changes in temperature and oxygen concentration which play an important role in embryonic development. Also, $K_{2P}$ channels are responsible for $K^+$ efflux during apoptotic volume decreases in mouse zygotes. These expression patterns and properties of the $K_{2P}$ channels in reproductive organs and germ cells are likely to help the understanding of ion channel-related function in reproductive physiology.

• The Korean Journal of Physiology and Pharmacology
• /
• v.21 no.2
• /
• pp.215-223
• /
• 2017

The effects of acidic pH on several voltage-dependent ion channels, such as voltage-dependent $K^+$ and $Ca^{2+}$ channels, and hyperpolarization-gated and cyclic nucleotide-activated cation (HCN) channels, were examined using a whole-cell patch clamp technique on mechanically isolated rat mesencephalic trigeminal nucleus neurons. The application of a pH 6.5 solution had no effect on the peak amplitude of voltage-dependent $K^+$currents. A pH 6.0 solution slightly, but significantly inhibited the peak amplitude of voltage-dependent $K^+$ currents. The pH 6.0 also shifted both the current-voltage and conductance-voltage relationships to the depolarization range. The application of a pH 6.5 solution scarcely affected the peak amplitude of membrane currents mediated by HCN channels, which were profoundly inhibited by the general HCN channel blocker $Cs^+$ (1 mM). However, the pH 6.0 solution slightly, but significantly inhibited the peak amplitude of HCN-mediated currents. Although the pH 6.0 solution showed complex modulation of the current-voltage and conductance-voltage relationships, the midpoint voltages for the activation of HCN channels were not changed by acidic pH. On the other hand, voltage-dependent $Ca^{2+}$ channels were significantly inhibited by an acidic pH. The application of an acidic pH solution significantly shifted the current-voltage and conductance-voltage relationships to the depolarization range. The modulation of several voltage-dependent ion channels by an acidic pH might affect the excitability of mesencephalic trigeminal nucleus neurons, and thus physiological functions mediated by the mesencephalic trigeminal nucleus could be affected in acidic pH conditions.

• Korean Journal of Acupuncture
• /
• v.28 no.3
• /
• pp.85-98
• /
• 2011

Objectives : The aim of this thesis is to examine the effect of acupuncture treatment at the GB37 on normal humans by using the power spectral analysis of the EEG. Methods : EEG (Electroencephalogram) power spectrum exhibits site-specific and state-related differences in specific frequency bands. In this thesis, the power spectrum was measured by the complexity. the 32 channels EEG study was carried out in the 13 subjects (12 males ; age=22.58 years old, 1 females ; 22 years old). Results : In the ${\alpha}$ (alpha) band, the power values at F7, F3, F4, F8, FTC2, C4, T4, CP1, CP2, TCP2, TT2, Pz, P4, Po1, Po2, O1, Oz, O2 channels (p<0.05) during the GB37-acupoint treatment were significantly changed. And in many channels were decreased. In the ${\beta}$ (beta) band, the power values at Cz, C4, T4, Tcp1, T6, Po1, O1, Oz, O2 channels (p<0.05) during the GB37-acupoint treatment were significantly changed. And in many channels were decreased. In the ${\delta}$(delta) band, the power values at Fp1, TT2 channels (p<0.05) during the GB37-acupoint treatment were significantly changed. And in many channels were decreased. In the $\theta$ (theta) band, the power values at Fp1, F8, FTC2, Pz channels (p<0.05) during the GB37-acupoint treatment were significantly changed. And in many channels were decreased. Conclusions : This results suggest that the acupuncture treatment at the GB37 significantly mostly change the power spectrum value on the alpha (18 channels), beta (9 channels) bands.

• Journal of Pharmacopuncture
• /
• v.6 no.3
• /
• pp.91-106
• /
• 2003

Objectives : The aim of this study was to examine the effects of electroacupuncture(EA) at the PC6(Naegwan) and the TE5 (Oegwan) on nounal humans using power spectral analysis. Methods : EEG power spectrum exhibit site-specific and state-related differences in specific frequency bands. In this study, power spectrum was used as a measure of complexity. 30 channel EEG study was carried out in 30 subjects(30 males ; age=23.7 years). Results : In ${\alpha}$(alpha) band, the power values at F7 channels(p<0.05) during the PC6-acupoint treatment were significantly were decreased. In ${\beta}$(beta) band, the power values at Fp1, Fz, TT1, T5, P3, P4, Po1, P02, O1, Oz, O2 channels(p<0.05) during the non-acupoint treatment and at Fp1, F4, F8 channels(p<0.05) during the TE5-acupoint treatment significantly were increased. In ${\theta}$(theta) band, the power values at Fp1 channels(p<0.05) during the non-acupoint treatment and at Oz channels(p<0.05) the TE5-acupoint treatment significantly were increased. but, the power values at F7 channels(p<0.05) during the non-acupoint treatment were significantly were decreased. In ${\delta}$(delta) band, the power values at TCP1, TCP2, CP1, T5 channels(p<0.05) during PC6-acupoint treatment were increased and the power values at F7, TT2 channels(p<0.05) during non-acupoint treatment were increased. but, the power values at the TE5-acupoint treatment significantly was decreased than the before-acupuncture treatment.

• The Korean Journal of Physiology and Pharmacology
• /
• v.2 no.4
• /
• pp.529-539
• /
• 1998

The effects of membrane surface charge originated from lipid head groups on ion channels were tested by analyzing the activity of single large conductance $Ca^{2+}-activated\;K^+$ (maxi K) channel from rat skeletal muscle. The conductances and open-state probability ($P_o$) of single maxi K channels were compared in three types of planar lipid bilayers formed from a neutral phosphatidylethanolamine (PE) or two negatively-charged phospholipids, phosphatidylserine (PS) and phosphatidylinositol (PI). Under symmetrical KCl concentrations $(3{\sim}1,000\;mM)$, single channel conductances of maxi K channels in charged membranes were $1.1{\sim}1.7$ times larger than those in PE membranes, and the differences were more pronounced at the lower ionic strength. The average slope conductances at 100 mM KCl were $251{\pm}9.9$, $360{\pm}8.7$ and $356{\pm}12.4$ $(mean{\pm}SEM)$ pS in PE, PS and PI membranes respectively. The potentials at which $P_o$ was 1/2, appeared to have shifted left by 40 mV along voltage axis in the membranes formed with PS or PI. Such shift was consistently seen at pCa 5, 4.5, 4 and 3.5. Estimation of the effect of surface charge from these data indicated that maxi K channels sensed the surface potentials at a distance of $8{\sim}9\;{\AA}$ from the membrane surface. In addition, similar insulation distance ($7{\sim}9\;{\AA}$) of channel mouth from the bilayer surface charge was predicted by a 3-barrier-2-site model of energy profile for the permeation of $K^+$ ions. In conclusion, despite the differences in structure and fluidity of phospholipids in bilayers, the activities of maxi K channels in two charged membranes composed of PS or PI were strikingly similar and larger than those in bilayers of PE. These results suggest that the enhancement of conductance and $P_o$ of maxi channels is mostly due to negative charges in the phospholipid head groups.

• Korean Journal of Acupuncture
• /
• v.23 no.1
• /
• pp.15-36
• /
• 2006

Objectives . The aim of this study was to examine the effect of electroacupuncture(EA) at the ST36 on normal humans by using power spectral analysis. Methods : EEG(Electroencephalogram) power spectral exhibits site-specific and state-related differences in specific frequency bands. In this study, power spectrum was used as a measure of complexity. 32 channel EEG study was carried out in 12 subjects (10 males; age=26.7 years old, 2females; age=28 years old). Results ; In ${\alpha}$ (alpha) band, the power values at Fp2, F7, F3, Fz, FTC1, FTC2, T3, C3, Cz, C4, TT1, TCP1, CP1, CP2,T5, P3, Pz, P4, Po1, Po2, O1, Oz,O2 channels(p<0.05) during the ST36-acupoint treatment were significantly increased. In ${\beta}$ (beta) band, the power values at Fp2, F7, F3, Fz, F4, F8, FTC1, FTC2, T3, C3, Cz, C4, TT1, TCP1, CP1, CP2, T5, P3, Pz, P4, Po1, Po2, O1, Oz, O2 channels(p<0.05) during the ST36-acupoint treatment were significantly decreased. In ${\delta}$ (delta) band, the power values at F7, Fz, T3, C3, TT1, TCP1, CP1, CP2, T5, P3, Pz,T6, Po1, PO2,O1, Oz, O2 channels(p<0.05) during the ST36-acupoint treatment were significantly decreased. In ${\theta}$(theta) band, the power values at F7, Fz, FTC1, T3, TCP1, CP2, TCP2, Po1, Po2 channels(p<0.05) during the ST36-acupoint treatment were significantly decreased. ${\alpha}$/${\beta}$ values at Cz, T5, O1, Oz, O2 channels during the ST36-acupoint treatment were increased. ${\beta}$/${\theta}$ values at Fpl, F7, F3, Fz, F4, F8, FTC1, FTC2, T3, C3, C4, T4, TT1, TCP1, TCP2, TT2, P3, P4, T6, Pol channels during the ST36-acupoint treatment were increased. Conclusions : This results suggest that Electroacupuncture at the ST36 mostly affects the charge on alpha(23 channels), beta(25 channels) bands.

• Korean Journal of Acupuncture
• /
• v.24 no.2
• /
• pp.193-216
• /
• 2007

Objectives : The aim of this study was to examine the effect of electroacupuncture (EA) at the PC8 on normal human beings by using power spectral analysis. Methods : EEG (Electroencephalogram) power spectrum exhibits site-specific and state-related differences in specific frequency bands. In this study, power spectrum was used as a measure of complexity. 32 channels EEG study was carried out in 20 subjects (20 males; age=26.8 years old). Results : In ${\alpha}(alpha)$ band, the power values at F7, F8, P3 channels(p<0.05) during the $PC_8-acupoint$ treatment significantly decreased. In ${\beta}(beta)$ band, the power values at F4, F8, P3 channels(P<0.05) during the PC8-acupoint treatment significantly decreased. In ${\delta}(delta)$ band, the power values at F7, F8, P3 Po2 channels(p<0.05) during the $PC_8-acupoint$ treatment significantly decreased. In ${\theta}(theta)$ band, the power values at F7, Fz, F4 F8, FTC1, FTC2, CP2, TT2, P3, Pz, Po2 channels(p<0.05) during the PC8-acupoint treatment significantly decreased. Conclusions : This results suggest that Electroacupuncture at the PC8 mostly affect the change on theta(11 channels) bands.

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

• Parasites, Hosts and Diseases
• /
• v.59 no.4
• /
• pp.329-339
• /
• 2021

Ion channels are important targets of anthelmintic agents. In this study, we identified 3 types of ion channels in Ascaris suum tissue incorporated into planar lipid bilayers using an electrophysiological technique. The most frequent channel was a large-conductance cation channel (209 pS), which accounted for 64.5% of channels incorporated (n=60). Its open-state probability (P_o) was ~0.3 in the voltage range of -60~+60 mV. A substate was observed at 55% of the main-state. The permeability ratio of Cl^- to K⁺ (P_Cl/P_K) was ~0.5 and P_Na/P_K was 0.81 in both states. Another type of cation channel was recorded in 7.5% of channels incorporated (n=7) and discriminated from the large-conductance cation channel by its smaller conductance (55.3 pS). Its Po was low at all voltages tested (~0.1). The third type was an anion channel recorded in 27.9% of channels incorporated (n=26). Its conductance was 39.0 pS and P_Cl/P_K was 8.6±0.8. P_o was ~1.0 at all tested potentials. In summary, we identified 2 types of cation and 1 type of anion channels in Ascaris suum. Gating of these channels did not much vary with voltage and their ionic selectivity is rather low. Their molecular nature, functions, and potentials as anthelmintic drug targets remain to be studied further.

• Korean Journal of Acupuncture
• /
• v.27 no.2
• /
• pp.141-157
• /
• 2010

Objectives : The aim of this study is to examine the effects of acupuncture at PC7(Daereung) on normal human EEG using power spectral analysis. Methods : EEG power spectrum exhibits site-specific and state-related differences in specific frequency bands. In this study, power spectrum was used as a measure of complexity. 30 subjects (16 males and 14 females; averaged age = 23.4 years) were engaged with thirty channel EEG study. Results : In $\alpha$(alpha) band, the power values at Fp1, Fp2, F7, F8 channels(p<0.05) during PC7 treatment were significantly decreased. But, the power values at Fz channel(p<0.05) during non-acupoint treatment was significantly decreased. In $\beta$(beta) band, the power values at Fp1, Fp2 channels(p<0.05) during PC7 treatment were significantly decreased. But, the power values at Fz channel(p<0.05) during non-acupoint treatment was significantly decreased and at F8, TCP2 channels(p<0.05) during non-acupoint treatment were increased. In $\theta$(theta) band, the power values at Fp1, Fp2, F7, F8 channels(p<0.05) during PC7 treatment were significantly decreased. But, the power values at Fz channel(p<0.05) during non-acupoint treatment was significantly decreased. In $\delta$(delta) band, the power values at Fp1, Fp2, F7, Fz, F8 channels (p<0.05) during PC7 treatment were significantly decreased. But, the power values at Fz channel (p<0.05) during non-acupoint treatment was significantly decreased. $\alpha/\beta$ values during PC7 treatment were decreased. $\beta/\theta$ values during PC7 treatment were decreased. Conclusion : These results suggest that acupuncture at PC7 induce the change on $\alpha$(alpha), $\beta$(beta), $\theta$ (theta), $\delta$(delta) wave values being decreased and and bothe $\alpha/\beta$ and $\beta/\theta$ values being decreased respectively. This is considered that acupuncture at PC7 affects the activity of cerebral cortex and endocrine system.