- 作者: Mieczystaw Pokorski; Magdalena Mmarczak; Urszula Jernajczyk
- 作者服務機構: Depatrment of Respiratory Research, Medical Research Center, Polish Academy of Sciences, Warsaw, Poland
- 中文摘要: --
- 英文摘要: In this study, we attempted to determine the role ofGABA neurotransmission in augmentation of hypoxicrespiration by antecedent hyperoxic breathing. The ex-periments were performed in anesthetized, paralyzedand vagotomized cats divided into control and bicucul-line (a GABA receptor blocker)-injected groups. Theexperimental protocol consisted of exposing the animalsto successive hypoxic-hyperoxic-hypoxic conditions.Respiration was assessed using phrenic electroneuro-grams, from which the peak phrenic height, a surrogateof the tidal volume component, and respiratory rate wereobtained, and their product, the respiratory minute out-put, was calculated. We found that prior hyperoxic venti-lation increased the subsequent respiratory response tohypoxia by an average of 23.5%, ompared with thepreoxygen response. This increase was driven by vol-ume respiration. The biphasic character of the hypoxicrespiratory response, consisting of stimulatory and de-pressant phases, was sustained. Bicuculline abolishedthe augmentative effect on hypoxic respiration of priorhyperoxia, which suggests that oxygenation inducesGABA -mediated hyperexcitability of respiratory neu-rons, possibly by the liberation of reactive oxygen spe-cies. We concluded that GABA neurotransmission is per-tinent to the effect of hyperoxia on hypoxic respiratoryreactivity.
- 中文關鍵字: --
- 英文關鍵字: --