caa a22 4500 475835530 CHVBK 20180406123851.0 cr unu---uuuuu 170329e20001101xx s 000 0 eng 10.1023/A:1010483831360 doi (NATIONALLICENCE)springer-10.1023/A:1010483831360 Impact of NMDA Receptors and Nitric Oxide on pH Sensitivity of Medullary Mechanisms Controlling Respiratory Rhythm [Elektronische Daten] [D. Volgin, M. Seredenko, D. Vasilenko, A. Volgina] We studied the dynamics of modifications of the respiratory activity generated by semi-isolated medullo-spinal preparations (SIMSP) of 3- to 4-day-old rats related to a drop in the pH of superfusing solution from 7.4 to 7.0. Reactions were recorded in the norm and under conditions of preliminary applications of a noncompetitive blocker of NMDA receptors, ketamine; an inhibitor of nitric oxide synthase (NOS), NG-nitro-L-arginine methyl ester (L-NAME); a substrate for NO synthesis, L-arginine; or an exogenous NO donor, sodium nitroprusside (SN). Under control conditions, test applications of the solution with pH 7.0 resulted in a significant increase in the frequency of inspiratory discharges (ID) recorded from the phrenic nerve and drops in their amplitude and integral intensity. Such SIMSP extracellular acidification-induced responses were inhibited in a dose-dependent manner by ketamine and L-NAME (the effect of the latter was more intensive). The effects of agents increasing the NO level in the tissues were not uniform: L-arginine potentiated an increase in the ID frequency related to application of the acidified solution, while SN inhibited such a reaction. Our findings allow us to suppose that the stimulating influences of the pH-sensitive chemoreceptor structures of the ventrolateral medulla (VLM) on the activity of the medullary respiratory generator of early postnatal rats are realized with the involvement of NMDA receptors of excitatory amino acids and the process of enzyme-mediated NO production. It seems probable that endogenous synthesis of NO in VLM structures mediates and potentiates the effect of activation of the NMDA receptors on the medullary generator of the respiratory rhythm. Plenum Publishing Corporation, 2000 respiratory generator nationallicence chemoreception nationallicence pH sensitivity nationallicence nitric oxide nationallicence NO synthase nationallicence NMDA receptors nationallicence Volgin D. Bogomolets Institute of Physiology, National Academy of Sciences of Ukraine, Kyiv, Ukraine aut Seredenko M. Bogomolets Institute of Physiology, National Academy of Sciences of Ukraine, Kyiv, Ukraine aut Vasilenko D. Bogomolets Institute of Physiology, National Academy of Sciences of Ukraine, Kyiv, Ukraine aut Volgina A. Bogomolets Institute of Physiology, National Academy of Sciences of Ukraine, Kyiv, Ukraine aut Neurophysiology Kluwer Academic Publishers-Plenum Publishers 32/6(2000-11-01), 360-367 0090-2977 32:6<360 2000 32 11062 https://doi.org/10.1023/A:1010483831360 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1010483831360 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Volgin D. Bogomolets Institute of Physiology, National Academy of Sciences of Ukraine, Kyiv, Ukraine aut NATIONALLICENCE 700 1- Seredenko M. Bogomolets Institute of Physiology, National Academy of Sciences of Ukraine, Kyiv, Ukraine aut NATIONALLICENCE 700 1- Vasilenko D. Bogomolets Institute of Physiology, National Academy of Sciences of Ukraine, Kyiv, Ukraine aut NATIONALLICENCE 700 1- Volgina A. Bogomolets Institute of Physiology, National Academy of Sciences of Ukraine, Kyiv, Ukraine aut NATIONALLICENCE 773 0- Neurophysiology Kluwer Academic Publishers-Plenum Publishers 32/6(2000-11-01), 360-367 0090-2977 32:6<360 2000 32 11062 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer