Do Carotid Chemoreceptors Contribute to Hyperthermia Induced Hyperventilation in Exercising Humans?
Notice bibliographique
Résumé
Hyperthermia increases ventilation in resting and exercising humans (White, J Appl Physiol 101: 655–663, 2006; Fujii et al. J Appl Physiol 104:998–1005, 2008), though what mechanisms mediate this response remains unclear. Carotid chemoreceptors can contribute to ventilatory regulation. Since hyperthermia can augment carotid chemoreceptor activity as demonstrated under in vitro conditions (Eyzaguirre and Zapata, J Appl Physiol 57: 931–957, 1984), this increased activity may in part mediate hyperthermia induced hyperventilation in humans. Regarding this, we previously reported that carotid chemoreceptor is not a main factor mediating hyperthermia induced hyperventilation at rest (Fujii et al. Exp Physiol 93: 994–1001, 2008). However, given hyperthermia induced hyperventilation differs between rest and exercise (Fujii et al. J Appl Physiol 104:998–1005, 2008), the results obtained at rest may not be representative of the response in exercise. Therefore, the purpose of this study was to evaluate whether carotid chemoreceptors contribute to hyperthermia‐induced hyperventilation in exercising humans. Eleven healthy young males (21 ± 3 years) performed cycling in the heat (37 °C) (35–55 min) at a fixed submaximal workload equal to ~55% of the individual's pre‐determined peak oxygen uptake. In order to suppress carotid chemoreceptor activity, 30‐s hyperoxic breathing (100% O 2 ) was performed at rest (before exercise), 5 min into exercise, as well as at increasing levels of hyperthermia as defined by an increase in esophageal temperature (an index of body core temperature) of 0.5, 1.0, and 1.5 °C above levels measured at 5‐min into exercise. Ventilation during exercise gradually increased as esophageal temperature increased (all P < 0.05), indicating that hyperthermia induced hyperventilation occurred. Carotid chemoreceptor inhibition with hyperoxic breathing suppressed ventilation at rest as well as during exercise regardless of the level of hyperthermia (all P < 0.05). Hyperoxia induced changes in ventilation (as assessed by % change from pre‐hyperoxic level) were −15 ± 7 % at rest and −15 ± 6 % at 5 min into exercise. The hyperoxia induced changes in ventilation during exercise for an esophageal temperature increase of 0.5, 1.0, and 1.5 °C were −18 ± 7 %, −17 ± 7 %, and −19 ± 8 %, all of which were not different from the 5‐min exercise level (all P > 0.05). These results demonstrate that carotid chemoreceptor contribution to ventilation during exercise is not modulated by the level of hyperthermia. Thus, we show that carotid chemoreceptors are not largely involved in the regulation of hyperthermia induced hyperventilation in exercising humans irrespective of state of hyperthermia. Support or Funding Information This study was supported by the grants from Ministry of Education, Culture, Sports, Science and Technology in Japan and Japan Society for the Promotion of Science. This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
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 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,001 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 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 ».