Enhanced c-Fos expression in the rostral ventral respiratory complex and rostral parapyramidal region by inhibition of the Na+/H+ exchanger type 3

摘要: Previous studies have shown that selective inhibition of Na+/H+ exchanger type 3 (NHE3) induces intracellular acidification and activates CO2/H+-sensitive medullary neurons, mimicking the responses evoked by hypercapnic stimuli. In addition, NHE3 blockers administration decreases duration apnoea induced laryngeal stimulation, presumably means central chemoreceptor activation. To test hypothesis network may be affected inhibition, brainstem c-Fos immunoreactive cell counting was performed after systemic blocker AVE1599 (Aventis Pharma Deutschland GmbH) (2 mg/kg). The rostro-caudal quantitative analysis showed a significant increase in number positive cells rostral part ventral respiratory complex (VRC) as well parapyramidal (Ppy) region. VRC activated region (-4.2 to -3.2mm interaural) included pre-Botzinger complex, group ventrolateral medulla, all them involved cardiorespiratory control. Ppy corresponded with chemosensitive area, which elicits strongest ventilatory response upon surface stimulation H+/CO2. Most were serotonergic. Hence, application induce chemoreceptors activation an activity similar way known physiological stimuli such hypercapnia. On other hand, could excellent tools for treatment pathological states where function is diminished or absent, hypoventilation syndrome sudden infant death syndrome.