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Hydroxy-α sanshool induces colonic motor activity in rat proximal colon: a possible involvement of KCNK9.

Kubota K, Ohtake N, Ohbuchi K, Mase A, Imamura S, Sudo Y, Miyano K, Yamamoto M, Kono T, Uezono Y - Am. J. Physiol. Gastrointest. Liver Physiol. (2015)

Bottom Line: Hydroxy-α sanshool (HAS), a readily absorbable active ingredient of TU-100 and a KCNK3/KCNK9/KCNK18 blocker as well as TRPV1/TRPA1 agonist, has been investigated for its effects on colonic motility.The effect of HAS was unaltered by TRPV1/TRPA1 antagonists and desensitization.HAS may evoke strong LDC possibly via blockage of the neural KCNK9 channel in the colonic myenteric plexus.

View Article: PubMed Central - PubMed

Affiliation: Tsumura Research Laboratories, Tsumura & Co., Ibaraki, Japan;

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HAS induces depolarization by blocking KCNK3 and KCNK9. A: 2-electrode voltage-clamp analysis with Xenopus oocytes expressing rat KCNK3 or KCNK9. Percent suppression of leak current was determined with a holding potential of +60 mV. Data are expressed as means ± SE for n = 4–8. *P < 0.05, **P < 0.01 vs. DMSO control. #P < 0.05, ###P < 0.001 vs. PBS control. B: kinetics of the changes of membrane potential responses induced by HAS, hydroxy-β sanshool (HBS), and lidocaine (Lid) in rat KCNK3- or KCNK9-expressing CHO-K1 cells. Application of compounds is indicated by “Apply.” Kinetics of the changes in membrane potential responses induced by 90 mM KCl is included as a positive control (n = 4). C: summary of normalized response to KCNK3, KCNK9, and mock cell by HAS, HBS, and Lid. Values represent the ΔF/F0 normalized to that of DMSO or PBS controls (mean ± SE for n = 4). *P < 0.05, **P < 0.01, ##P < 0.01.
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Figure 6: HAS induces depolarization by blocking KCNK3 and KCNK9. A: 2-electrode voltage-clamp analysis with Xenopus oocytes expressing rat KCNK3 or KCNK9. Percent suppression of leak current was determined with a holding potential of +60 mV. Data are expressed as means ± SE for n = 4–8. *P < 0.05, **P < 0.01 vs. DMSO control. #P < 0.05, ###P < 0.001 vs. PBS control. B: kinetics of the changes of membrane potential responses induced by HAS, hydroxy-β sanshool (HBS), and lidocaine (Lid) in rat KCNK3- or KCNK9-expressing CHO-K1 cells. Application of compounds is indicated by “Apply.” Kinetics of the changes in membrane potential responses induced by 90 mM KCl is included as a positive control (n = 4). C: summary of normalized response to KCNK3, KCNK9, and mock cell by HAS, HBS, and Lid. Values represent the ΔF/F0 normalized to that of DMSO or PBS controls (mean ± SE for n = 4). *P < 0.05, **P < 0.01, ##P < 0.01.

Mentions: It is not known whether HAS and HBS inhibit rat KCNK3 and/or KCNK9. Thus we conducted two electrode voltage-clamp assays using Xenopus oocytes expressing rat KCNK3 or KCNK9. Because both channels were reported to be regulated by extracellular pH, application of pH 6.5 solution was used as a positive control. Inhibitory effect of test compounds were determined with a holding potential of +60 mV. Lid was used as a nonselective KCNK channel blocker, which strongly inhibited both KCNK3 and KCNK9. As shown in Fig. 6A, HAS showed significant and dose-dependent inhibition against KCNK3 and KCNK9 whereas HBS inhibited only KCNK3. These results were comparable to those observed for murine KCNKs (1).


Hydroxy-α sanshool induces colonic motor activity in rat proximal colon: a possible involvement of KCNK9.

Kubota K, Ohtake N, Ohbuchi K, Mase A, Imamura S, Sudo Y, Miyano K, Yamamoto M, Kono T, Uezono Y - Am. J. Physiol. Gastrointest. Liver Physiol. (2015)

HAS induces depolarization by blocking KCNK3 and KCNK9. A: 2-electrode voltage-clamp analysis with Xenopus oocytes expressing rat KCNK3 or KCNK9. Percent suppression of leak current was determined with a holding potential of +60 mV. Data are expressed as means ± SE for n = 4–8. *P < 0.05, **P < 0.01 vs. DMSO control. #P < 0.05, ###P < 0.001 vs. PBS control. B: kinetics of the changes of membrane potential responses induced by HAS, hydroxy-β sanshool (HBS), and lidocaine (Lid) in rat KCNK3- or KCNK9-expressing CHO-K1 cells. Application of compounds is indicated by “Apply.” Kinetics of the changes in membrane potential responses induced by 90 mM KCl is included as a positive control (n = 4). C: summary of normalized response to KCNK3, KCNK9, and mock cell by HAS, HBS, and Lid. Values represent the ΔF/F0 normalized to that of DMSO or PBS controls (mean ± SE for n = 4). *P < 0.05, **P < 0.01, ##P < 0.01.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4385894&req=5

Figure 6: HAS induces depolarization by blocking KCNK3 and KCNK9. A: 2-electrode voltage-clamp analysis with Xenopus oocytes expressing rat KCNK3 or KCNK9. Percent suppression of leak current was determined with a holding potential of +60 mV. Data are expressed as means ± SE for n = 4–8. *P < 0.05, **P < 0.01 vs. DMSO control. #P < 0.05, ###P < 0.001 vs. PBS control. B: kinetics of the changes of membrane potential responses induced by HAS, hydroxy-β sanshool (HBS), and lidocaine (Lid) in rat KCNK3- or KCNK9-expressing CHO-K1 cells. Application of compounds is indicated by “Apply.” Kinetics of the changes in membrane potential responses induced by 90 mM KCl is included as a positive control (n = 4). C: summary of normalized response to KCNK3, KCNK9, and mock cell by HAS, HBS, and Lid. Values represent the ΔF/F0 normalized to that of DMSO or PBS controls (mean ± SE for n = 4). *P < 0.05, **P < 0.01, ##P < 0.01.
Mentions: It is not known whether HAS and HBS inhibit rat KCNK3 and/or KCNK9. Thus we conducted two electrode voltage-clamp assays using Xenopus oocytes expressing rat KCNK3 or KCNK9. Because both channels were reported to be regulated by extracellular pH, application of pH 6.5 solution was used as a positive control. Inhibitory effect of test compounds were determined with a holding potential of +60 mV. Lid was used as a nonselective KCNK channel blocker, which strongly inhibited both KCNK3 and KCNK9. As shown in Fig. 6A, HAS showed significant and dose-dependent inhibition against KCNK3 and KCNK9 whereas HBS inhibited only KCNK3. These results were comparable to those observed for murine KCNKs (1).

Bottom Line: Hydroxy-α sanshool (HAS), a readily absorbable active ingredient of TU-100 and a KCNK3/KCNK9/KCNK18 blocker as well as TRPV1/TRPA1 agonist, has been investigated for its effects on colonic motility.The effect of HAS was unaltered by TRPV1/TRPA1 antagonists and desensitization.HAS may evoke strong LDC possibly via blockage of the neural KCNK9 channel in the colonic myenteric plexus.

View Article: PubMed Central - PubMed

Affiliation: Tsumura Research Laboratories, Tsumura & Co., Ibaraki, Japan;

Show MeSH
Related in: MedlinePlus