Mechanical ventilation triggers hippocampal apoptosis by vagal and dopaminergic pathways.
Am J Respir Crit Care Med
; 188(6): 693-702, 2013 Sep 15.
Article
em En
| MEDLINE
| ID: mdl-23962032
RATIONALE: Critically ill patients frequently develop neuropsychological disturbances including acute delirium or memory impairment. The need for mechanical ventilation is a risk factor for these adverse events, but a mechanism that links lung stretch and brain injury has not been identified. OBJECTIVES: To identify the mechanisms that lead to brain dysfunction during mechanical ventilation. METHODS: Brains from mechanically ventilated mice were harvested, and signals of apoptosis and alterations in the Akt survival pathway were studied. These measurements were repeated in vagotomized or haloperidol-treated mice, and in animals intracerebroventricularly injected with selective dopamine-receptor blockers. Hippocampal slices were cultured and treated with micromolar concentrations of dopamine, with or without dopamine receptor blockers. Last, levels of dysbindin, a regulator of the membrane availability of dopamine receptors, were assessed in the experimental model and in brain samples from ventilated patients. MEASUREMENTS AND MAIN RESULTS: Mechanical ventilation triggers hippocampal apoptosis as a result of type 2 dopamine receptor activation in response to vagal signaling. Activation of these receptors blocks the Akt/GSK3ß prosurvival pathway and activates the apoptotic cascade, as demonstrated in vivo and in vitro. Vagotomy, systemic haloperidol, or intracerebroventricular raclopride (a type 2 dopamine receptor blocker) ameliorated this effect. Moreover, ventilation induced a concomitant change in the expression of dysbindin-1C. These results were confirmed in brain samples from ventilated patients. CONCLUSIONS: These results prove the existence of a pathogenic mechanism of lung stretch-induced hippocampal apoptosis that could explain the neurological changes in ventilated patients and may help to identify novel therapeutic approaches.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Respiração Artificial
/
Nervo Vago
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Dopamina
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Apoptose
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Lesão Pulmonar Induzida por Ventilação Mecânica
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Hipocampo
Tipo de estudo:
Prognostic_studies
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Risk_factors_studies
Limite:
Animals
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Humans
Idioma:
En
Revista:
Am J Respir Crit Care Med
Assunto da revista:
TERAPIA INTENSIVA
Ano de publicação:
2013
Tipo de documento:
Article