Effects of short‐term heat acclimation on whole‐body heat exchange and local nitric oxide synthase‐ and cyclooxygenase‐dependent heat loss responses in exercising older men
Bibliographic record
Abstract
New Findings What is the central question of this study? Does short‐term heat acclimation enhance whole‐body evaporative heat loss and augment nitric oxide synthase (NOS)‐dependent cutaneous vasodilatation and NOS‐ and cyclooxygenase (COX)‐dependent sweating, in exercising older men? What is the main finding and its importance? Our preliminary data ( n = 8) demonstrated that short‐term heat acclimation improved whole‐body evaporative heat loss, but it did not influence the effects of NOS and/or COX inhibition on cutaneous vasodilatation or sweating in older men during an exercise–heat stress. These outcomes might imply that although short‐term heat acclimation enhances heat dissipation in older men, it does not modulate NOS‐ and COX‐dependent control of cutaneous vasodilatation or sweating on the forearm. Abstract Ageing is associated with decrements in whole‐body heat loss (evaporative + dry heat exchange), which might stem from alterations in nitric oxide synthase (NOS)‐ and cyclooxygenase (COX)‐dependent cutaneous vasodilatation and sweating. We evaluated whether short‐term heat acclimation would (i) enhance whole‐body heat loss primarily by increasing evaporative heat loss, and (ii) augment NOS‐dependent cutaneous vasodilatation and NOS‐ and COX‐dependent sweating, in exercising older men. Eight older men [mean (SD) age, 59 (8) years] completed a calorimetry and microdialysis trial before and after 7 days of exercise–heat acclimation. For the calorimetry trials, whole‐body evaporative and dry heat exchange were assessed using direct calorimetry during 30 min bouts of cycling at light, moderate and vigorous metabolic heat productions (150, 200 and 250 W/m 2 , respectively) in dry heat (40°C, 20% relative humidity). For the microdialysis trials, local cutaneous vascular conductance and sweat rate were assessed during 60 min exercise in the heat (35°C, 20% relative humidity) at four dorsal forearm skin sites treated with lactated Ringer solution (control), NOS inhibitor, COX inhibitor or combined NOS and COX inhibitors, via microdialysis. Evaporative heat loss during moderate ( P = 0.036) and vigorous ( P = 0.021) exercise increased after acclimation. Inhibition of NOS alone reduced cutaneous vascular conductance to a similar extent before and after acclimation ( P < 0.040), whereas separate and combined NOS and COX inhibition had no significant effects on sweating relative to the control site ( P = 0.745). Our preliminary results might suggest that short‐term heat acclimation improves evaporative heat loss, but does not significantly modulate the contributions of NOS or COX to cutaneous vasodilatation or sweating on the forearm in older men during an exercise–heat stress.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".