Changes in short-term potentiation of hypoglossal activity by modulators of nitric oxide production in the rabbit.
Stimulation of the superior laryngeal nerve (SLN) causes a potentiation of hypoglossal nerve activity persisting after cessation of stimulation. The mechanism of this phenomenon is uncertain. We investigated a potential role of the nitric oxide (NO) pathway in modulation of the after-effects of SLN stimulation on phrenic and hypoglossal activity in rabbits. L-Arginine, a substrate for NO synthesis and NG-Nitro-L-Arginine (L-NNA) an inhibitor of NO synthase (NOS), were administered systemically. L-Arginine and L-NNA alone caused small changes in respiratory activity. During pre-treatment with NO precursor the amplitude and duration of hypoglossal potentiation evoked by SLN stimulation were reduced. Systemic NO synthase inhibition partially reversed these effects of L-Arginine. The results showed that interference with NO production by NO substrate and NOS inhibitor modulates the effects of SLN stimulation on hypoglossal activity. Nitric oxide might be a negative modulator of the transmission of short-term potentiation (STP) in hypoglossal activity.
Budzińska
K
K
Department of Neurophysiology, Medical Research Centre, Polish Academy of Sciences, 5 Pawiński St., 02-106 Warsaw, Poland. kbudzinska@medres.cmdik.pan.pl.
Wojtal
E
E
D000200:Action Potentials / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D001120:Arginine / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects; D004558:Electric Stimulation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D007002:Hypoglossal Nerve / Q000502:physiology*; D008297:Male; D009569:Nitric Oxide / Q000096:biosynthesis*; D019335:Nitroarginine / Q000494:pharmacology; D010791:Phrenic Nerve / Q000502:physiology; D011817:Rabbits
D004791:Enzyme Inhibitors; D019335:Nitroarginine; D009569:Nitric Oxide; D001120:Arginine