Acute stress augments obstructive apneas and related O<sub>2</sub>-desaturations in urethane-anesthetised rats <i>via</i> disruption of cholinergic modulation
Notice bibliographique
Résumé
Obstructive sleep apnea (OSA) is a multifactorial respiratory disorder affecting nearly 1 billon of adults worldwide. Anomalies in respiratory control during sleep contribute to airway obstructions and recurrent desaturations; however, the origins of the problem are not well known. Stress disrupts brain function and increases the risk of OSA co-morbidities, including hypertension and obesity. Because, hypothalamic structures regulating the stress response also project to medullary areas regulating cardiorespiratory function and airway motor control, we hypothesised that exposure to a single stress session is suffcient to induce cardiorespiratory disturbances associated with OSA. Experiments were performed in urethane-anesthetised rats; this approach allows sleep-like brain state alternations with significant reductions in upper airway (genioglossus; GG), but not diaphragmatic (DIA), muscle tone during the transition from NREM-like to REM-like states. Adult male rats were either subjected to a 90 min session of immobilisation stress (n = 21) or handled briefly by the experimenter (n = 18). 24h later, rats were anesthetised (urethane, 1.6 g/kg; i.v.) and instrumented to monitor DIA and GG EMG. O2 saturation was measured by pulse oximetry (S pO2). Blood pressure was measured by an arterial catheter. Rats were placed in a supine position and respiratory airflow was measure by a temperature probe near the nares. Obstructive apneas were identified by the absence of airflow in the presence of DIA activity with a S pO2 drop greater than 3%. Stress did not affect distribution of sleep-like states or the state-related changes in phasic GG activity. However, stress augmented the incidence of obstructive apneas (0.5 vs 2.2 events/h; p = 0.05) and doubled the severity of desaturations associated with apneas (-6% vs -12% drop; p = 0.03). Pre-treatment with atropine (0.5 mg/kg) reduced obstructive apneas (drug effect: p = 0.04). Atropine blocked apnea-related O2 desaturations in stressed but not controls (apnea x stress x atropine: p = 0.04). Atropine treatment augmented GG activity; this effect was greater in NREM-like state, especially in stressed rats (atropine x state x stress: p = 0.05). We conclude that, in urethane anesthetised rats, stress disrupts cardiorespiratory control in ways that favor significant obstructive apneas. Disruption of cholinergic modulation of GG activity and cardiovascular function likely contributes to this process. These data point to an important factor in the onset of OSA. While the frequency of apneas was modest we propose that recurrent exposure to stressors or more significant events will worsen the condition over time. Supported by the Canadian Institutes of Health Research and the Foundation of the Québec Heart & Lung Institute. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.
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Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,001 | 0,000 |
| Méta-épidémiologie (sens large) | 0,001 | 0,001 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,001 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,002 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».