Influence of the Estrous Cycle on c-fos and CRH Gene Transcription in the Brain of Endotoxin-Challenged Female Rats
Notice bibliographique
Résumé
The purpose of this study was to investigate whether the ovulatory cycle interferes with the effect of the acute-phase response of a systemic immune activation on the transcription of the immediate early gene c-fos and the stress-related neuropeptide corticotropin-releasing hormone (CRH) in the brains of female rats. Throughout the day of proestrus and diestrus-2 (09.00, 12.00, 15.00 h), adult rats received either a single intraperitoneal injection of the endotoxin lipopolysaccharide (LPS, 200 micrograms/100 g body weight) or the vehicle solution and were killed 3 h later (12.00, 15.00, 18.00 h). Frozen brains were mounted on a microtome, cut in 30-micron slices and then processed for the detection of c-fos mRNA and CRH primary transcript (heteronuclear [hnRNA]) by means of in situ hybridization histochemistry using 35S-labeled exonic and intronic probes, respectively. LPS injection induced a profound expression of c-fos mRNA in the several nuclei and areas of the brain, such as the organum vasculosum of the lamina terminalis/medial preoptic area, supraoptic nucleus, parvo- and magnocellular divisions of the hypothalamic paraventricular nucleus (PVN), arcuate nucleus/median eminence, central nucleus of the amygdala, locus coeruleus, nucleus of the solitary tract, area postrema and ventrolateral medulla. Interestingly, the intensity of expression of c-fos mRNA depended on the phase of the estrous cycle and/or the time of the day. Indeed, in several of the structures described above, LPS induced a more pronounced c-fos signal in the morning of proestrus than the afternoon and diestrus-2. CRH primary transcript was significantly increased by LPS treatment selectively in the parvocellular division of the PVN and the highest hybridization signal was observed in the morning of proestrus, a period where a large number of c-fos-positive cells were colocalized in CRH-immunoreactive neurons. A significant increase in the levels of AVP hnRNA was also observed in the parvocellular PVN of animals sacrificed at noon and early afternoon of both pro- and diestrus days. These results provide evidence that the neuroendocrine events regulating the reproductive cyclicity influence the endotoxin-induced activation of the early gene c-fos in selective structures of the brain and the stimulation of neurons directly involved in the regulation of the HPA axis. It is possible that the gonadal status of female mammals plays a crucial role in the integration of the organism in the presence of foreign material in preventing an exaggerated immune response during particular phases of the ovulatory cycle. The capacity of female animals to modulate the intensity through which the neuronal circuitry activated during immunogenic processes is likely to be an elegant sexual dimorphism participating in the adjustment of the responses in line with the physiological demand.
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 distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| 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) | 0,000 | 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 tête enseignante, 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 ».