Administration of prostacyclin modulates cutaneous blood flow but not sweating in young and older males: roles for nitric oxide and calcium‐activated potassium channels
Notice bibliographique
Résumé
Key points In young adults, cyclooxygenase (COX) contributes to the heat loss responses of cutaneous vasodilatation and sweating, and this may be mediated by prostacyclin‐induced activation of nitric oxide synthase (NOS) and calcium‐activated potassium (KCa) channels. This prostacyclin‐induced response may be diminished in older relative to young adults because ageing is known to attenuate COX‐dependent heat loss responses. We observed that, although prostacyclin does not mediate sweating in young and older males, it does modulate cutaneous vasodilatation, although the magnitude of increase is similar between groups. We also found that, although NOS and KCa channels contribute to prostacyclin‐induced cutaneous vasodilatation in young males, these contributions are diminished in older males. Our findings provide new insight into the mechanisms governing heat loss responses and suggest that the age‐related diminished COX‐dependent heat loss responses reported in previous studies may be a result of the reduced COX‐derived production of prostanoids (e.g., prostacyclin) rather than the decreased sensitivity of prostanoid receptors. Abstract Cyclooxygenase (COX) contributes to the regulation of cutaneous vasodilatation and sweating; however, the mechanism(s) underpinning this response remain unresolved. We hypothesized that prostacyclin (a COX‐derived product) may directly mediate cutaneous vasodilatation and sweating through nitric oxide synthase (NOS) and calcium‐activated potassium (KCa) channels in young adults. However, these responses would be diminished in older adults because ageing attenuates COX‐dependent cutaneous vasodilatation and sweating. In young (25 ± 4 years) and older (60 ± 6 years) males (nine per group), cutaneous vascular conductance (CVC) and sweat rate were evaluated at four intradermal forearm skin sites: (i) control; (ii) 10 m m N G ‐nitro‐ l ‐arginine ( l ‐NNA), a non‐specific NOS inhibitor; (iii) 50 m m tetraethylammonium (TEA), a non‐specific KCa channel blocker; and (iv) 10 m m l ‐NNA + 50 m m TEA. All four sites were coadministered with prostacyclin in an incremental manner (0.04, 0.4, 4, 40 and 400 μ m each for 25 min). Prostacyclin‐induced increases in CVC were similar between groups (all concentrations, P > 0.05). l ‐NNA and TEA, as well as their combination, lowered CVC in young males at all prostacyclin concentrations ( P ≤ 0.05), with the exception of l ‐NNA at 0.04 μ m ( P > 0.05). In older males, CVC during prostacyclin administration was not influenced by l ‐NNA (all concentrations), TEA (4‐400 μ m ) or their combination (400 μ m ) ( P > 0.05). No effect on sweat rate was observed in either group (all concentrations, P > 0.05). We conclude that, although prostacyclin does not mediate sweating, it modulates cutaneous vasodilatation to a similar extent in young and older males. Furthermore, although NOS and KCa channels contribute to the prostacyclin‐induced cutaneous vasodilatation in young males, these contributions are diminished in older males.
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 distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| 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) | 0,000 | 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 tête enseignante, 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 ».