6981 tocris bioscience 1594 10 timp3 r d system 973 tm tissue tek sakura 4583  (Tocris)

Journal: Frontiers in Physiology

Article Title: Presynaptic Mechanisms and KCNQ Potassium Channels Modulate Opioid Depression of Respiratory Drive

doi: 10.3389/fphys.2019.01407

Figure Lengend Snippet: Pharmacological properties of drugs and dosages used.

Article Snippet: The following vendors provided DAMGO ([D-Ala 2 , NMe-Phe 4 , Gly-ol 5 ]-enkephalin), XE991, Chromanol 293B ((-)-[3R,4S]-Chromanol 293B), retigabine, ICA 69673, TertiapinQ, and ML297: Tocris Biosciences/R&D Systems (Minneapolis, MN), Cayman Chemicals (Ann Arbor, MI), Alomone Labs (Jerusalem, Israel), Sigma-Aldrich/Millipore-Sigma (St. Louis, MO, United States).

Techniques: In Vivo

Journal: Frontiers in Physiology

Article Title: Presynaptic Mechanisms and KCNQ Potassium Channels Modulate Opioid Depression of Respiratory Drive

doi: 10.3389/fphys.2019.01407

Figure Lengend Snippet: Exemplary records of fictive inspiratory bursts recorded from in vitro preBötC slices in response to increasing titers of activators or blockers of KCNQ and GIRK potassium channels, mimicking or reversing opioid-induced respiratory depression (OIRD). Integrated recording (top), instantaneous burst frequency (below). (A) Inspiratory bursts as a function of increasing titers of ICA 69673, a KCNQ activator (0.1, 0.5, 2.0, in mM), mimicking OIRD. (B) Inspiratory bursts as a function of increasing titers of retigabine (RTG), an FDA-approved KCNQ activator (0.1, 0.5, 1.0, 3.0, in mM), mimicking OIRD. (C) Rescue of DAMGO-induced OIRD (100 nM) with increasing titers of Chromanol 293B (293B), a KCNQ blocker (10, 50, 100, in mM). (D) Rescue of DAMGO-induced OIRD (100 nM) with increasing titers of XE991, a KCNQ blocker (1, 3, 30, 60, in mM). (E) Failure to rescue DAMGO-induced OIRD (100 nM) with increasing titers of TertiapinQ (TPQ), a GIRK blocker (5, 15, 60, 100, in nM). (F) Failure to mimic OIRD by increasing titers of ML297, a GIRK activator (3, 10, 30, in mM). Transient apneas observed at the beginning of washes (A–D) are an artifact of temperature drop or oxygen desaturation from perfusion exchanges.

Article Snippet: The following vendors provided DAMGO ([D-Ala 2 , NMe-Phe 4 , Gly-ol 5 ]-enkephalin), XE991, Chromanol 293B ((-)-[3R,4S]-Chromanol 293B), retigabine, ICA 69673, TertiapinQ, and ML297: Tocris Biosciences/R&D Systems (Minneapolis, MN), Cayman Chemicals (Ann Arbor, MI), Alomone Labs (Jerusalem, Israel), Sigma-Aldrich/Millipore-Sigma (St. Louis, MO, United States).

Techniques: In Vitro

Journal: Frontiers in Physiology

Article Title: Presynaptic Mechanisms and KCNQ Potassium Channels Modulate Opioid Depression of Respiratory Drive

doi: 10.3389/fphys.2019.01407

Figure Lengend Snippet: Pharmacological interrogations of in vitro preBötC slices suggests a modulatory role for KCNQ potassium channels in opioid-induced respiratory depression (OIRD), and a minor role for GIRK potassium channels. ( A , left) Dose-response curves of inspiratory burst frequencies in response to increasing titers of DAMGO, and two activators of KCNQ potassium channels (ICA 69673, Retigabine) which act on different structural domains of the channel subunit. Both activators inhibit burst frequencies with an IC 50 = ∼0.7–1.0 μM, comparable to their EC 50 for activation of KCNQ channels. ( A , right) Dose-response curves of inspiratory burst frequencies in response to increasing titers of ML297, a GIRK1 subunit specific activator. Modest depression of burst frequencies, at concentrations 10–100-fold higher than the EC 50 s (0.16–0.9 μM) for GIRK1 containing heteromeric channels. ( B , left) Dose-response curves of inspiratory burst frequency in response to increasing titers of the KCNQ blockers XE991 and Chromanol 293B (293B), applied in the presence of DAMGO (100 nM) to suppress respiratory rhythms. ( B , right) Dose-response curves of inspiratory burst frequency in response to increasing titers of TertiapinQ (TPQ), a GIRK-specific blocker, applied in the presence of DAMGO (100 nM). No recovery of respiratory burst frequency was observed at the highest concentration of TPQ (100 nM). By contrast, both KCNQ blockers partially rescued respiratory rhythms suppressed by DAMGO, at relatively high concentrations (20–100 μM). Shown above plots are the EC 50 s and IC 50 s of each compound for specific molecular species of homo- and hetero-tetrameric GIRK and KCNQ channels reported in the literature (see text and for references). Mean and SE plotted for DAMGO and TertiapinQ; median and IQR plotted for all other datasets, along with individual replicant values: DAMGO ( N = 35), ICA 69673 ( N = 14), Retigabine ( N = 6), ML297 ( N = 6), XE991 ( N = 7), Chromanol 293B ( N = 5), TertiapinQ ( N = 9).

Article Snippet: The following vendors provided DAMGO ([D-Ala 2 , NMe-Phe 4 , Gly-ol 5 ]-enkephalin), XE991, Chromanol 293B ((-)-[3R,4S]-Chromanol 293B), retigabine, ICA 69673, TertiapinQ, and ML297: Tocris Biosciences/R&D Systems (Minneapolis, MN), Cayman Chemicals (Ann Arbor, MI), Alomone Labs (Jerusalem, Israel), Sigma-Aldrich/Millipore-Sigma (St. Louis, MO, United States).

Techniques: In Vitro, Activation Assay, Concentration Assay

Journal: Frontiers in Physiology

Article Title: Presynaptic Mechanisms and KCNQ Potassium Channels Modulate Opioid Depression of Respiratory Drive

doi: 10.3389/fphys.2019.01407

Figure Lengend Snippet: Whole-body plethysmography from awake, unanesthetized neonatal and adult mice, in response to systemic delivery of GIRK1 activator (ML297) or KCNQ activator (retigabine; RTG). Profound suppression of respiratory frequency by KCNQ activator, but only modest suppression by GIRK1 activator. (A) Modest reduction of respiratory frequency with ML297 (50 mg/kg, IP) from a neonatal pup. Representative plethysmography recordings before ( Ai , top), and after drug injection ( Ai , bottom). (Aii) Distributions of instantaneous breath frequencies from the same animal, fitted to single Gaussian distributions. (B) Large reduction of respiratory frequency with retigabine (10 mg/kg, IP) from a neonatal pup. Plethysmography records before ( Bi , top) and after drug injection ( Bi , bottom). (Bii) Distributions of instantaneous breath frequencies from the same animal, fitted to single Gaussian distributions. (C) Summary of plethysmography data for neonates (P7–13) and adults (P25–60), normalized to baseline respiratory frequencies. Both neonates and adults exhibited modest and similar reductions (∼10%) in respiratory frequency with ML297. However, retigabine caused large reductions in respiratory frequency in both neonates (46% reduction) and adults (20% reduction). Adult respiratory suppression by retigabine was significantly stronger than ML297 ( p = 0.012; t -test). Results from vehicle controls (DMSO; IP) with neonates and adults were not significantly different and pooled. Population mean and SE plotted, along with individual responses derived from means of fitted Gaussian curves, for each condition, for neonatal retigabine ( N = 11), neonatal ML297 ( N = 12), adult retigabine ( N = 9), adult ML297 ( N = 6), DMSO control ( N = 8). Statistical significance: ∗∗∗ p < 0.0001, ∗∗ p = 0.0003, by un-paired t –test.

Article Snippet: The following vendors provided DAMGO ([D-Ala 2 , NMe-Phe 4 , Gly-ol 5 ]-enkephalin), XE991, Chromanol 293B ((-)-[3R,4S]-Chromanol 293B), retigabine, ICA 69673, TertiapinQ, and ML297: Tocris Biosciences/R&D Systems (Minneapolis, MN), Cayman Chemicals (Ann Arbor, MI), Alomone Labs (Jerusalem, Israel), Sigma-Aldrich/Millipore-Sigma (St. Louis, MO, United States).

Techniques: Injection, Derivative Assay, Control