Biphasic effect of ethyl alcohol on short-term potentiation of the respiratory activity in the rabbit.
This study investigated the effects of systemic alcohol injections on respiratory activity and short-term potentiation (STP) of the phrenic nerve and hypoglossal nerve activities, evoked by electrical stimulation of the superior laryngeal nerve (SLN), in anesthetized, paralyzed, and artificially ventilated rabbits. Alcohol, in a dose of 500 mg/kg, given singly or in cumulative fractions of 100mg/kg, depressed hypoglossal activity with little or no effect on phrenic activity. SLN stimulation inhibited both phrenic and hypoglossal activities and this effect remained unchanged by either way of alcohol administration. After cessation of stimulation, hypoglossal activity increased above the control level and slowly declined to the baseline, showing signs of STP. The amplitude and duration of the hypoglossal STP decreased following a single dose of alcohol. Cumulative fractions of the alcohol dose evoked a biphasic effect on the respiratory STP. In a lower range, alcohol enhanced the hypoglossal STP and tended to increase the duration of the phrenic STP. This effect gradually declined with increasing cumulative dose of alcohol and finally reversed to the inhibition of the STP of both nerves. The results demonstrate a dose-dependent biphasic effect of alcohol on the induction and maintaining of the hypoglossal STP. A reduction in STP, together with hypoglossal activity depression following alcohol accumulation, may contribute to the facilitation of upper airway obstruction by alcohol.
Budzińska
K
K
Department of Respiratory Research, Medical Research Center, Polish Academy of Science, Warsaw, Poland. kbudzinska@cmdik.pan.pl
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D000431:Ethanol / Q000008:administration & dosage / Q000494:pharmacology*; D007002:Hypoglossal Nerve / Q000187:drug effects*; D007275:Injections, Intravenous; D007823:Laryngeal Nerves / Q000502:physiology*; D008168:Lung / Q000294:innervation*; D009473:Neuronal Plasticity / Q000187:drug effects*; D010791:Phrenic Nerve / Q000187:drug effects*; D011817:Rabbits; D012119:Respiration / Q000187:drug effects*; D013997:Time Factors
D000431:Ethanol