The Contractile Effects of Oxytocin, Ergonovine, and Carboprost and Their Combinations
Bibliographic record
Abstract
BACKGROUND: The objective of this study was to compare the in vitro contractile effects of the combination of oxytocin (low dose and high dose) with either ergonovine or carboprost in myometrial strips from women undergoing cesarean delivery (CD), and to study the effect of oxytocin pretreatment on these contractions. We hypothesized that the use of ergonovine or carboprost in combination with oxytocin would improve contractility compared with oxytocin alone. METHODS: Myometrial samples obtained from women undergoing elective CD were pretreated in organ bath chambers with either oxytocin 10 M (experimental) or physiological salt solution (control) for 2 hours. They were then washed and subjected to dose-response testing with oxytocin, ergonovine, or carboprost (10 to 10 M), either alone or in combination with a fixed low-dose (10 M) (LDOx) or high-dose (10 M) (HDOx) oxytocin. The amplitude, frequency, area under the curve, and motility index (amplitude × frequency) of contractions during the dose-response period were analyzed with linear regression models, and compared among the groups. The primary outcome was the motility index across the study groups. RESULTS: One hundred sixty-nine experiments were done in samples obtained from 56 women. The mean square root of the motility index [standard error] (√g·contractions/10 min) of oxytocin was significantly higher in the control (3.40 [0.24]) versus experimental group (2.02 [0.15]) (P < 0.001). When all control groups were compared, the motility index of oxytocin (3.21 [0.25]) was higher than that of ergonovine (2.13 [0.30], P < 0.001 [multiple comparisons adjusted P value, P < 0.001]), carboprost (1.88 [0.10], P < 0.001 [P < 0.001]), ergonovine + LDOx (2.07 [0.15], P < 0.001 [P < 0.001]), and carboprost + LDOx (1.82 [0.15], P < 0.001 [P < 0.001]) and was not different than that of ergonovine + HDOx (3.39 [0.32], P = 0.68 [P = 0.99]) and carboprost + HDOx (2.68 [0.30], P = 0.20 [P = 0.60]). However, in oxytocin-pretreated groups, carboprost + LDOx (motility index: 2.53 [0.08], P = 0.001 [multiple comparisons adjusted P value, P = 0.002]) and ergonovine + HDOx (2.82 [0.15], P < 0.001 [P < 0.001]) exhibited significantly superior contractility response compared with oxytocin alone, while ergonovine + LDOx (2.47 [0.13], P = 0.01 [P = 0.08]) and carboprost + HDOx (2.51 [0.20], P = 0.05 [P = 0.24]) showed higher mean contractility response compared with oxytocin alone but failed to reach statistical significance in adjusted analyses. CONCLUSIONS: The attenuation of oxytocin-induced contractility in oxytocin-pretreated myometrial strips is in keeping with the previously established oxytocin-receptor desensitization phenomenon. Oxytocin is the most effective of the uterotonics tested if the myometrium is not preexposed to oxytocin. However, in the oxytocin-pretreated myometrium, a synergistic response is evident, and the combination of oxytocin with either ergonovine or carboprost produces superior response compared with oxytocin alone. Further in vivo studies in humans are necessary to determine whether these differences identified in vitro are clinically significant.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| 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) | 0.001 | 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 source (direct Gemma or distilled Codex), 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".