91 Can propylene glycol modulate insulin and insulin-like growth factor-1 in superovulated dairy heifers?
Notice bibliographique
Résumé
The aim of this study was to determine the effect of propylene glycol (PPG) on serum concentrations of insulin and insulin-like growth factor (IGF)-1 in superovulated dairy heifers. We hypothesised that administration of PPG would have a positive effect on superovulation results via increased insulin and IGF-1. A total of 20 clinically healthy Holstein heifers with an average age of 12 months were used for this experiment. Superovulation was performed using a standard protocol. Briefly, each heifer received 3 mg of oestradiol-17ß IM and an intravaginal progesterone-releasing insert (CIDR) containing 1.9 g of progesterone at random stages of the oestrous cycle (designated Day 0). From Day 4 to 8, heifers received a total of 200 mg of NIH-follicle-stimulating hormone-P1 administered intramuscularly through 9 injections of decreasing doses (from 50 to 10 mg) at 12-h intervals. On Day 7, heifers received 2 injections of 500 µg of cloprostenol, a PGF2a analogue, at ~6-h intervals, after which intravaginal inserts were removed. Artificial insemination was performed on Day 10, 12 h after treatment with 100 µg of gonadotropin-releasing hormone IM. Embryos were flushed from the uterus of donor heifers 6 days after AI. The method consisted of simultaneously using 1 catheter per uterine horn. Catheters were maintained in place to perform 2 flushes 1 h apart. A total of 1 L of flushing medium was used, 700 and 300 mL for the first and the second flush, respectively. Embryos were assessed for viability immediately after collection using the IETS classification. Heifers were divided into 2 groups (PPG and control group). From Day 4 to 14 of the superovulation protocol, PPG group received a daily dose of 400 mL of a 66.7% propylene glycol solution, whereas the control group received the same amount of water. Two months later, the same experiment was conducted by inverting the groups. At Day 4 and 14, four blood samples were collected to measure insulin and IGF-1 at 25-min intervals. The first sample (0) was taken before heifers received PPG or water. Insulin was analysed using an ELISA kit following manufacturer’s instructions, whereas IGF-1 was determined using a chemiluminescence immunoassay. Embryo associated data were analysed using t-test. Both IGF-1 and insulin data were analysed using a two-way ANOVA, followed by Bonferroni post-hoc test. Treatment with PPG had no effect on the number of transferable embryos (8 ± 5.1 v. 7 ± 5.5), degenerated embryos (0.5 ± 0.8 v. 1.5 ± 2.4), or unfertilized oocytes (0.3 ± 0.7 v. 0.7 ± 1.2) recovered. There was also no effect of PPG on IGF-1 serum concentrations at the beginning (Day 4) or the end (Day 14) of the treatment regimen. However, PPG treatment enhanced (P = 0.02) serum insulin concentrations 50 min after administration on Day 4 (10.69 v. 6.88 pmol/L), as well as at 25 (19.58 v. 9.64 pmol/L) and 50 min (16.67 v. 8.21 pmol/L) on Day 14. It has been suggested that PPG metabolism may stimulate insulin and IGF-1 secretion, which can promote embryo development. However, in the present study, there was no effect of oral doses of PPG on IGF-1. Although higher serum concentrations of insulin were observed after PPG treatment, there was no effect of PPG treatment on the number of transferable embryos recovered following superovulation.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| 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) | 0,001 | 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 source (Gemma direct ou Codex distillé), 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 ».