Oxidative metabolism of peripheral blood neutrophils in experimental acute hypercapnia in the mechanically ventilated rabbit.

Background And Aim: The aim of this study was to investigate the effect of acute hypercapnia due to the mechanical hypoventilation on the oxidative metabolism of peripheral blood neutrophils in the rabbit.

Methods: The study was performed on 24 Chinchilla rabbits, randomized into normo- and hypercapnia groups (P(a)CO(2) between 9 and 11 kPa over 180 min). At the baseline point and after 180 min of mechanical ventilation, a neutrophil count, luminol-dependent chemiluminescence of the neutrophils stimulated with opsonized zymosan (OZ) or PMA (phorbol myristate acetate), and the hydrogen peroxide production of the cells upon the PMA stimulation were measured. Serum cortisol levels were additionally determined.

Results: In both studied groups, a significant neutrophilia after 180 min of mechanical ventilation was observed (P<.05). Neither chemiluminescence nor hydrogen peroxide production of peripheral neutrophils was changed (P>.05).

Conclusions: Hypercapnia lasting for 180 min did not affect the oxidative metabolism of circulating neutrophils but a rise in a neutrophil count was observed in the mechanically ventilated rabbit.