Vasoconstrictor activity of arginine vasopressin in rat small mesenteric arteries after hindlimb suspension
Bibliographic record
Abstract
One of the factors responsible for orthostatic hypotension after spaceflight is an inability to adequately maintain cardiac afterload. Arginine vasopressin (AVP) increases arterial blood pressure by controlling both blood volume (antidiuresis) and total peripheral resistance (vasoconstriction). Plasma levels of AVP have been recently reported to increase after simulated microgravity. The present study aimed to investigate the vasoconstrictor activity of AVP on peripheral resistance vessels (small mesenteric arteries) in a hindlimb‐unloaded (HU) rat model. Male Long Evans rats were tail‐suspended at 35 degrees for 14 days. Small mesenteric arteries (2 nd order) were isolated and pressurized at 70 mmHg in a pressure myograph. Sensitivity and maximal responses to AVP (10 −12 to 3x10 −8 M) were assessed. There was no difference between HU and Control groups with regard to either EC 50 (HU: 6.8±1.2 x 10 −10 M, n = 8; Control: 7.9±1.7 x 10 −10 M, n = 6) or maximal response to AVP. Contrary to a previous report of hyporesponsiveness to AVP in rat aorta after hindlimb suspension, the activity of this hormone in resistance‐sized mesenteric vessels of male rats is not changed by exposure to simulated microgravity. This research was supported by The Canadian Space Agency.
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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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 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 | 0.001 |
| 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".