Identification and Characterization of GAL-021 as a Novel Breathing Control Modulator. (November 2015)

• Record Type: Journal Article
• Authors: Golder, Francis J.; Dax, Scott; Baby, Santhosh M.; Gruber, Ryan; Hoshi, Toshinori; Ideo, Courtney; Kennedy, Andrew; Peng, Sean; Puskovic, Veljko; Ritchie, David; Woodward, Richard; Wardle, Robert L.; Van Scott, Michael R.; Mannion, James C.; MacIntyre, D. Euan
• Is Part Of: Anesthesiology. Volume 123:Number 5(2015)
• Publication Date: 2015-11
• Subjects: Anesthesiology -- Periodicals; Anesthetics -- Periodicals; Anesthesia -- Periodicals; 617.9605
• DOI: 10.1097/ALN.0000000000000844
• Languages: English
• ISSNs: 0003-3022

Abstract

Abstract : Background: The authors describe the preclinical pharmacological properties of GAL-021, a novel peripheral chemoreceptor modulator. Methods: The ventilatory effects of GAL-021 were characterized using tracheal pneumotachometry (n = 4 to 6), plethysmography (n = 5 to 6), arterial blood gas analyses (n = 6 to 11), and nasal capnography (n = 3 to 4) in naive animals and those subjected to morphine-induced respiratory depression. Morphine analgesia in rats was evaluated by tail-flick test (n = 6). Carotid body involvement in GAL-021 ventilatory effects was assessed by comparing responses in intact and carotid sinus nerve–transected rats. Hemodynamic effects of GAL-021 were evaluated in urethane-anesthetized rats (n = 7). The pharmacological profile of GAL-021 in vitro was investigated using radioligand binding, enzyme inhibition, and cellular electrophysiology assays. Results: GAL-021 given intravenously stimulated ventilation and/or attenuated opiate-induced respiratory depression in rats, mice, and nonhuman primates, without decreasing morphine analgesia in rats. GAL-021 did not alter mean arterial pressure but produced a modest increase in heart rate. Ventilatory stimulation in rats was attenuated by carotid sinus nerve transection. GAL-021 inhibited KCa 1.1 in GH3 cells, and the evoked ventilatory stimulation was attenuated in Slo1 −/− mice lacking the pore-forming α-subunit of the KCa 1.1 channel. Conclusions: GAL-021 behaved as a breathing control modulator in rodents and nonhuman primates and diminished opioid-induced respiratory depression without compromising opioid analgesia. It acted predominantly at the carotid body, in part by inhibiting KCa 1.1 channels. Its preclinical profile qualified the compound to enter clinical trials to assess effects on breathing control disorders such as drug (opioid)-induced respiratory depression and sleep apnea. Abstract : Intravenously administered GAL-021 attenuated opiate-induced respiratory depression in rats and nonhuman primates without affecting morphine analgesia in rats. GAL-021 ventilatory stimulation in rats was attenuated by carotid sinus nerve transection. GAL-021 ventilatory stimulation was attenuated in mice lacking the pore-forming α-subunit of the KCa 1.1 channel.