1. Figure 6. Effects of exercise training on aging-induced alteration of MaxiK channel activity and gating properties in mesenteric artery myocytes. (A–C) Representative recordings of single-channel currents at a membrane voltage of +40 mV in Young, O-SED, and O-EX groups (1 μM [Ca²⁺]_free in the bath solution), respectively. (D–F) Summary of the MaxiK channel conductance, normalized Np_o, and time constant, respectively. (G) Effect of tamoxifen (1 μM) on MaxiK channel activity in three groups. Bar plot summarizes the mean ± SEM fold change in the normalized Np_o of MaxiK channels after the application of Tam. [Ca²⁺]_free in the bath solution: 0.1 μM. Holding potential = + 40 mV. *p < .01, compared with Young group. ^#p < .01, compared with O-SED group; n = 6 in each group. τ_o, time constant of open state; τ_c, time constant of close state.
From: Exercise Training Reverses Unparallel Downregulation of MaxiK Channel α- and β1-Subunit to Enhance Vascular Function in Aging Mesenteric Arteries
J Gerontol A Biol Sci Med Sci. 2013;69(12): doi: /gerona/glt205
J Gerontol A Biol Sci Med Sci | © The Author Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please

2. Figure 1. Effect of exercise on norepinephrine (NE)–induced cardiovascular responses in Young, O-SED, and O-EX rats. (A, C, and E) NE-induced systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) responses, respectively. 0 min: time for intravenous injection of NE (18 μg/kg). *p < .05, compared with the baseline level. (B, D, and F) The maximal change of the SBP (ΔSBP), DBP (ΔDBP), and HR (ΔHR), respectively. *p < .05, compared with Young; ^#p < .05, compared with O-SED; n = 6 in each group.
From: Exercise Training Reverses Unparallel Downregulation of MaxiK Channel α- and β1-Subunit to Enhance Vascular Function in Aging Mesenteric Arteries
J Gerontol A Biol Sci Med Sci. 2013;69(12): doi: /gerona/glt205
J Gerontol A Biol Sci Med Sci | © The Author Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please

3. Figure 2. Effects of MaxiK channel inhibitor iberiotoxin (IbTX) on the norepinephrine (NE)–induced vessel contraction in mesenteric arteries from Young, O-SED, and O-EX rats. Vessels were first contracted with 10⁻⁵ M NE (gray traces). Following washing and reequilibration to basal tones (45 minutes later), the vessel were pretreated with IbTX (10⁻⁸ M) for 2 minutes and then stimulated with 10⁻⁵ M NE in the presence of IbTX (black traces). The representative vessel contraction traces were shown in A (Young), B (O-SED), and C (O-EX). (D) Statistic diagram of IbTX pretreatment on the NE-induced vessel contraction. *p < .05, compared with NE-induced tension in the same group; ^#p < .05, compared with Young. (E) The maximal increase of NE-induced vessel contraction (ΔNE) in three groups. *p < .05, compared with Young; ^#p < .05, compared with O-SED; n = 6 in each group.
From: Exercise Training Reverses Unparallel Downregulation of MaxiK Channel α- and β1-Subunit to Enhance Vascular Function in Aging Mesenteric Arteries
J Gerontol A Biol Sci Med Sci. 2013;69(12): doi: /gerona/glt205
J Gerontol A Biol Sci Med Sci | © The Author Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please

4. Figure 3. Whole-cell K⁺ currents in myocytes of MA measured using the conventional whole-cell configuration of the patch clamp technique. (A) Young; (B) O-SED; (C) O-EX. (a) Typical recordings of whole-cell K⁺ currents measured during depolarizing voltage steps. (b) Whole-cell K⁺ current measured after the treatment of IbTX (100nM) for 10 minutes. (c) The mean current density vs voltage plot in the absence (closed circles, n = 6) or presence (open circles, n = 6) of IbTX in myocytes from three groups.
From: Exercise Training Reverses Unparallel Downregulation of MaxiK Channel α- and β1-Subunit to Enhance Vascular Function in Aging Mesenteric Arteries
J Gerontol A Biol Sci Med Sci. 2013;69(12): doi: /gerona/glt205
J Gerontol A Biol Sci Med Sci | © The Author Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please

5. Figure 4. Measurement of spontaneous transient outward current (STOC) activity in freshly isolated MA myocytes from Young, O-SED, and O-EX rats. STOCs were recorded by means of the perforated patch clamp technique. (A) Representative STOC recordings in Young animals. Depolarizing test potentials were gradually increased in 10 mV increments from −40 to 0 mV. (B) Expanded traces of STOCs at holding potential of −30 mV in three groups. (C and D) Summarized data of STOC amplitude (C) and frequency (D) at membrane potential of −30 mV. *p < .01, compared with Young group_;^#p < .01, compared with O-SED group; n = 6 in each group.
From: Exercise Training Reverses Unparallel Downregulation of MaxiK Channel α- and β1-Subunit to Enhance Vascular Function in Aging Mesenteric Arteries
J Gerontol A Biol Sci Med Sci. 2013;69(12): doi: /gerona/glt205
J Gerontol A Biol Sci Med Sci | © The Author Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please

6. Figure 5. Effect of exercise training on Ca²⁺/voltage sensitivity of MaxiK channel in mesenteric artery myocytes from Young, O-SED, and O-EX groups. (A) Voltage dependence of MaxiK channel in the 1 μM Ca²⁺. The line was drawn according to the best fits with the Boltzmann equation. (B) Effect of exercise training on Ca²⁺ dependence of MaxiK channel. The data points were fitted with the Hill equation to obtain the calcium concentration necessary to open half of the channels (K_d) and the Hill coefficient(η^H); n = 6 in each group.
From: Exercise Training Reverses Unparallel Downregulation of MaxiK Channel α- and β1-Subunit to Enhance Vascular Function in Aging Mesenteric Arteries
J Gerontol A Biol Sci Med Sci. 2013;69(12): doi: /gerona/glt205
J Gerontol A Biol Sci Med Sci | © The Author Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please

7. Figure 7. Expression of MaxiK channel α-subunit and β1-subunit in mesenteric smooth muscle membranes from Young, O-SED, and O-EX groups. Each lane was loaded with 20 μL (2 μg/μL) of supernatant from mesenteric arteries (MAs). (A) Immunoreactive bands corresponding to α-subunit, β1-subunit, and β-actin in the MA myocytes detected by Western blot. (B and C) Summarized data of α-subunit (B) and β1-subunit (C) protein levels expressed as a ratio to β-actin. (D) Summarized β1/α ratio; n = 6 in each group. *p < .01, compared with Young group_;^#p < .01, compared with O-SED group.
From: Exercise Training Reverses Unparallel Downregulation of MaxiK Channel α- and β1-Subunit to Enhance Vascular Function in Aging Mesenteric Arteries
J Gerontol A Biol Sci Med Sci. 2013;69(12): doi: /gerona/glt205
J Gerontol A Biol Sci Med Sci | © The Author Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please