Interactions Between Reproductive Hormones and Neuro-Vascular Regulation During the Cold Pressor Test in Young Females
Notice bibliographique
Résumé
Recently, we reported that muscle sympathetic nerve activity (MSNA) is not predictive of vascular nor blood pressure outcomes during the cold pressor test (CPT) in young healthy females. Instead, we observed substantial variability in vascular responses to the CPT which ranged widely from decreases in blood flow and vascular conductance to increases in these same outcomes. Interindividual differences in circulating reproductive hormones may account for this female-specific variability in vascular responses to acute elevations in MSNA. Therefore, the purpose of this study was to test the hypothesis that reproductive hormones account for variability in MSNA, femoral blood flow (FBF), and femoral vascular conductance (FVC) during the CPT in females. We retrospectively assessed data from 9 young healthy females (age: 24±3 years) in the low hormone phase of their menstrual cycle (days 1-5). Intravenous blood samples were obtained and prospectively analyzed to assess concentrations of circulating reproductive hormones (radioimmunoassay). Integrated peroneal MSNA (microneurography; NeuroAmpEX, ADI) was quantified at rest and during a 3-minute hand CPT. Mean arterial pressure (MAP) was measured beat-by-beat (Finometer Midi, FMS) and duplex vascular ultrasound was used to measure FBF; FVC was quantified as FBF/MAP (mL/min/mmHg). All variables are expressed as the difference between the average CPT value and the average baseline value. CPT-induced changes in MSNA burst incidence (bursts/100hb) were not related to [17-beta-estradiol] (R 2 =0.05; P=0.60), [progesterone] (R 2 =0.11, P=0.47), or [free testosterone] (R 2 =0.01, P=0.81). Similarly, changes in FBF and FVC were not related to [17-beta-estradiol] (FBF: R 2 =0.04, P=0.67; FVC: R 2 =0.01, P=0.80) or [progesterone] (FBF: R 2 =0.04, P=0.67; FVC: R 2 =0.09, P=0.51). However, there was a negative correlation between [free testosterone] and the changes in both FBF (R 2 =0.69, P=0.02) and FVC (R 2 =0.66, P=0.03). In other words, females with higher free testosterone demonstrated larger decreases in FBF and FVC during the CPT relative to those with lower free testosterone concentrations. These data suggest that circulating free testosterone may act to increase the vasoconstrictive consequences of MSNA in females, and may account for the previously observed variability in vascular responses to MSNA during acute stress. This project was funded by: NSERC and FRQ-S. 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 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 ».