The Influence of Heat Shock Protein 90 on Sweating and Cutaneous Vasodilation in Older Adults Exercising in the Heat
Notice bibliographique
Résumé
Heat Shock Protein 90 (HSP90) is involved in numerous cellular enzymatic processes and it is up‐regulated during exercise in the heat in a variety of cell types. In vitro and in vivo evidence indicates that HSP90 directly enhances nitric oxide (NO) bioavailability via binding to and stabilization of NO synthase. In young males, we previously demonstrated a role for HSP90 in mediating cutaneous vasodilation, but not sweating, during exercise in the heat and this effect was determined to be NO‐dependent. Healthy ageing attenuates both cutaneous vasodilation and sweating responses during exercise in the heat, in part, due to reduced NO bioavailability. However, the contribution of HSP90 in mediating these heat loss responses in older adults remains poorly understood. Thus, the purpose of this study was to evaluate the contribution of HSP90 in modulating sweating and cutaneous vasodilation in healthy habitually active older adults exercising in the heat and to determine whether this contribution acts through the NO pathway. Eleven (M=8; F=3) healthy older adults (55 ± 5 years) exercised for 50 min at 55% VO 2peak in the heat (35°C, 30% relative humidity). Cutaneous vascular conductance (CVC, measured via laser Doppler flowmetry) and sweating (measured via ventilated capsules) were measured at four forearm skin sites receiving either: 1) Lactated Ringer's solution (Control), 2) 10 mM N G ‐nitro‐L‐arginine methyl ester (L‐NAME, a specific NO synthase inhibitor), 3) 178 mM Geldanamycin (Gelda, an HSP90 inhibitor), or 4) a combination of 10 mM L‐NAME +178 mM Gelda (L+G), via intradermal microdialysis. A 5% DMSO solution was used to fully dissolve Gelda, and was also added to the other sites for consistency. At the end of exercise, CVC was not different between Gelda (68 ± 18% CVC max ) and Control (65 ± 12% CVC max ; all P < 0.05) sites. However, CVC was reduced at L‐NAME (52 ± 20% CVC max ) and L+G (52 ± 17% CVC max ) sites, relative to both Control and Gelda sites (all P<0.05). Sweat rates were lower at the end of exercise for Gelda (1.38 ± 0.89 mg/min/cm 2 ), L‐NAME (1.16 ± 0.69 mg/min/cm2) and L+G (1.37 ± 0.79 mg/min/cm2) sites, relative to Control (1.51 ± 0.93 mg/min/cm2) (all P<0.05). Furthermore, sweating was reduced at the L‐NAME site relative to both Gelda and L+G sites (both P<0.05). In summary, these results demonstrate that in healthy habitually active older adults exercising in the heat, HSP90 inhibition does not influence cutaneous vasodilation, despite a clear role for NO in this response. Conversely, HSP90 does attenuate the sweating response in this group. The underlying reasons for the differing effects of HSP90 inhibition on cutaneous vasodilation and sweating between younger and older adults require further investigation. Support or Funding Information Funding support: Canadian Institutes of Health Research (held by Dr. Kenny). 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 | 0,000 |
| 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 | 0,000 | 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 ».