Effect of Adrenomedullin on Placental Arteries in Normal and Preeclamptic Pregnancies
Bibliographic record
Abstract
Adrenomedullin is a potent vasodilatory peptide with plasma levels that increase during pregnancy. Although fetoplacental adrenomedullin levels are reported to increase in preeclampsia, maternal plasma levels may be elevated or decreased, or they may resemble those in normal pregnancy. In other hypertensive conditions, adrenomedullin increases. Therefore, we hypothesized that maternal plasma adrenomedullin levels would be higher in hypertensive pregnancies than in normotensive pregnancies and that the higher placental resistance found in preeclamptic pregnancies results from blunted activity of adrenomedullin on the vasculature. Adrenomedullin concentrations in plasma from women with normotensive pregnancies, gestational hypertension, and preeclampsia were determined by radioimmunoassay. Stem villous arteries from normotensive and preeclamptic pregnancies were dissected and mounted on a wire myograph system. Arteries were first preconstricted to 80% of their maximum constriction with U46619, a thromboxane A(2) mimetic, and exposed to cumulative doses of adrenomedullin (1x10(-)(9) to 3x10(-)(7) mol/L). Contrary to our hypothesis, there were no significant differences in maternal plasma adrenomedullin levels among patients with normal pregnancies, gestational hypertension, and preeclampsia. Adrenomedullin significantly relaxed arteries from both normal and preeclamptic placentas, but there was no significant difference between the 2 groups. During normal pregnancy, adrenomedullin may contribute to the low placental vascular resistance. This pathway appears to be intact in preeclampsia. We conclude that the increased placental vascular resistance observed in preeclampsia is due neither to reduced adrenomedullin secretion nor to an attenuated vascular responsiveness. Moreover, unlike other hypertensive disorders, there is no compensatory rise in circulating adrenomedullin levels.
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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 | 0.000 | 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 | 0.000 |
| 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".