Dextromethorphan (DEX) is a widely used non-opioid antitussive. However, the precise site of action and its mechanism were not fully understood. We examined the effects of DEX on AMPA receptor-mediated glutamatergic transmission in the nucleus tractus solitarius (NTS) of guinea pigs.
View Article and Find Full Text PDFThe present study investigated whether the platelet-derived growth factor receptor (PDGFR)-beta-mediated mechanisms are involved in the hypoxic ventilatory response through modulating the N-methyl-D-aspartate (NMDA) function. The ventilatory changes during hypoxic challenge (10% O(2), 30 min) were measured plethysmographically in mice selectively lacking the PDGFR-beta in neurons (KO mice) and in control wild-type mice (WT mice) before and after blockade of NMDA receptors. In baseline breathing at rest, respiratory rate, tidal volume, and minute ventilation were similar between WT and KO mice.
View Article and Find Full Text PDFCough reflex is characterized by a large expulsive phase for expelling the mucus or particles from the airway. The present study investigated the involvement of N-methyl-D-aspartate (NMDA) mechanisms in the expulsive phase of cough reflex using decerebrate and paralyzed cats. A fictive cough was induced by repetitive stimulation of the superior laryngeal nerve, which was characterized by an increased inspiratory discharge in the phrenic nerve (the stage 1 of fictive cough; SC1) and large spindle-shaped discharge in the iliohypogastric nerve (the stage 2 of fictive cough; SC2).
View Article and Find Full Text PDFAs an interesting type of molecular recognition at a membrane surface, the tri-O-acetic acid ester (host 2) of hexahomotrioxacalix[3]arene, when incorporated into poly(vinyl chloride) (PVC) liquid membranes, displays a high potentiometric selectivity for dopamine over, not only other catecholamines (noradrenaline, adrenaline), but also quaternary ammonium guests (tetramethylammonium, choline, and acetylcholine) and inorganic cations (Na+, K+, NH4+). Interestingly, changes in membrane potential based on the host-guest complexation of host 2 that were observed dopamine/inorganic cation selectivity were not displayed by the related hosts 3 and 4, which contain amide substituents. This paper describes our efforts to separately estimate the two factors contributing to the dopamine selectivities, i.
View Article and Find Full Text PDFNew ditopic sensory elements 2 and 3 for catecholamines based on a hexahomotrioxacalix[3]arene, with a boronic acid substituent appended, were designed and synthesized. As an interesting mode of molecular recognition at membrane surfaces, the host, when incorporated into poly(vinyl chloride) (PVC) liquid membranes, displayed excellent potentiometric selectivity for dopamine over other catecholamines (noradrenaline and adrenaline) and inorganic cations (Na+, K+, and NH4+).
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