The content of gonadotropin-releasing hormone (GnRH), kisspeptin, and estrogen receptors (ERα/ERβ) in the anteromedial hypothalamus displays daily variations throughout the rat estrous cycle.
Olvera-Juárez. Esteban E; Silva. Carlos-Camilo CC; Flores. Angélica A; Arrieta-Cruz. Isabel I; Mendoza-Garcés. Luciano L; Martínez-Coria. Hilda H; López-Valdés. Héctor E HE; Cárdenas. Mario M; Domínguez. Roberto R; Gutiérrez-Juárez. Roger R; Cruz. María-Esther ME
Key Findings
- Kisspeptin levels in the anteromedial hypothalamus vary by time of day and estrous stage
- Estrogen receptor alpha and beta levels shift across the cycle, with ERβ often higher on the right side
- GnRH and kisspeptin are higher in the right hypothalamus during proestrus and estrus, and FSH/LH peaks occur at different times depending on the cycle stage
Practical Outcomes
- The study suggests that timing could influence how kisspeptin‑based or hormone‑modulating interventions work, but it’s a rat study and doesn’t provide direct dosing or protocol guidance for humans. Biohackers should view this as basic science indicating circadian effects rather than a ready‑to‑use method.
Summary
In rats, the amount of kisspeptin and related hormones in a specific brain region changes throughout the day and across the reproductive cycle, and the right side of that region usually has higher levels. This shows that hormone levels are not constant but follow daily and cycle‑related patterns.
Abstract
The content of gonadotropin-releasing hormone (GnRH), its mRNA, and estrogen receptor alpha (ERα) and beta (ERβ) in the hypothalamus varies throughout the estrous cycle. Furthermore, the abundance of these molecules displays asymmetry between the right and left side. In the present study, we investigated the changes in the content of ERα, ERβ, kisspeptin, and GnRH by western blot in the left and right anteromedial hypothalamus, at four different times during each stage of the rat estrous cycle. The serum levels of the follicle-stimulating hormone (FSH) and luteinizing hormone (LH) were also measured. ERα and ERβ levels changed depending on the stage of the estrous cycle, meanwhile that of kisspeptin was modified according to both the hour of the day and the stage of the cycle. Except in estrus day, ERβ was higher in the right hypothalamus, while ERα was similar in both sides. During both proestrus and estrus, the content of kisspeptin and GnRH was higher in the right hypothalamus. The highest levels of FSH and LH occurred at 17:00 h of proestrus. But at estrus, the highest FSH levels were observed at 08:00 h and the lowest at 17:00 h. Thus, the current results show that the content of ERα, ERβ, kisspeptin, and GnRH in the anteromedial hypothalamus are regulated as a function of the stage of the estrous cycle and the hour of the day. Furthermore, the content of these proteins is regularly higher in the right anteromedial hypothalamus, regardless of the stage of the cycle or time of the day.
Study Information
pubmed
2020
2020-07-24T00:00:00.000Z
10.1007/s00441-020-03258-x
6
57