Abstract
ABSTRACT. We examined the effect of hypoxia (FIO2 = 0.10) on methionine-enkephalin concentrations in brainstem nuclei involved in the integration of cardiopulmonary control in 3− and 21-day-old rabbits. Rabbit pups were confined in environmental chambers for 6 h and exposed to one of four conditions. Control, 21% O2 for 6 h; intermittent hypoxia, 12 cycles of 20 min 21% O2 followed by 10 min of 10% O2; acute hypoxia, 4 h of 21% O2 followed by 2 h of 10% O2; recovery, 2 h of 10% O2 followed by 4 h of 21% O2. Methionine-enkephalin was measured by radioimmunoassay in the nucleus tractus solitarius, nucleus ambiguus, nucleus parabrachialismedialis, and nucleus reticulogigantocellularis. In 3-day-old rabbits, exposure to 10% O2 did not affect methionine-enkephalin concentrations in any brainstem nuclei studied. In contrast, 21-day-old pups demonstrated a decrease in methionine-enkephalin concentration in three of the four nuclei studied when exposed to intermittent hypoxia, as well as an apparent ability to recover from an acute hypoxic exposure (p < 0.05). These data support an age-, nucleus-, and stimulus-specific effect of hypoxia on methionine-enkephalin concentration within specific brainstem nuclei and suggest a possible mechanism for the newborn's increased cardiopulmonary instability under hypoxia.
Similar content being viewed by others
Article PDF
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Gingras-Leatherman, J., Mcnamara, M. & Lawson, E. Age-Dependent Influence of Hypoxia on Methionine-Enkephalin Concentration within Rabbit Brainstem Nuclei. Pediatr Res 20, 655–657 (1986). https://doi.org/10.1203/00006450-198607000-00015
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1203/00006450-198607000-00015