Resumen

SAKURABA, SHIGEKI et al. Effects of neuromuscular blocking agents on central respiratory chemosensitivity in newborn rats. Biol. Res. [online]. 2005, vol.38, n.2-3, pp.225-233. ISSN 0716-9760.  http://dx.doi.org/10.4067/S0716-97602005000200012.

Neuromuscular blocking agents suppress central respiratory activity through their inhibitory effects on preinspiratory neurons and the synaptic drive from preinspiratory neurons to inspiratory neurons. Central CO₂-chemosensitive areas, which partly consist of CO₂-excited neurons, in the rostral ventrolateral medulla are thought to provide tonic drive to the central respiratory network and involve cholinergic mechanisms, which led us to hypothesize that neuromuscular blocking agents can inhibit CO₂-excited neurons and attenuate respiratory CO₂ responsiveness. To test this hypothesis, we used isolated brainstem-spinal cord preparations from newborn rats. The increase of C4 burst frequency induced by a hypercapnic superfusate, i.e. respiratory CO₂ responsiveness, was suppressed by the application of neuromuscular blocking agents, either d-tubocurarine (10, 100μM) or vecuronium (100μM). These agents (40μM) also induced hyperpolarization and decreases in firing frequency of CO₂-excited neurons in the rostral ventrolateral medulla. Our results demonstrate that neuromuscular blocking agents inhibit CO₂-excited tonic firing neurons and attenuate respiratory CO₂ responsiveness.

Palabras clave : brainstem; chemosensitivity; CO₂ responsiveness; muscle relaxant; nicotinic acetylcholine.

        · texto en Inglés     · Inglés ( pdf )