cFos-mediated β-Arrestin1 in the RVLM alleviates sympathetic hyperactivity induced by ovariectomy.

Area of Science:

• Cardiovascular Physiology
• Neuroendocrinology

Background:

• Sympathetic hyperactivity is linked to cardiovascular dysfunction in postmenopausal women.
• Mechanisms of menopause-induced sympathetic hyperactivity are unclear.
• β-arrestin1 and cFos are implicated in blood pressure regulation.

Purpose of the Study:

• To investigate if β-arrestin1, regulated by cFos in the rostral ventrolateral medulla (RVLM), contributes to menopause-induced sympathetic hyperactivity.
• To explore the role of estrogen in modulating β-arrestin1 expression in the RVLM.

Main Methods:

• Established a postmenopausal rat model using bilateral ovariectomy (OVX).
• Measured β-arrestin1 and cFos expression in the RVLM.
• Manipulated β-arrestin1 and cFos expression in OVX rats.
• Administered estrogen to OVX rats.

Main Results:

• Ovariectomy reduced RVLM β-arrestin1 expression; estrogen supplementation increased it.
• Overexpressing β-arrestin1 in OVX rats attenuated sympathetic hyperactivity and hypertension.
• Reducing β-arrestin1 compromised estrogen's cardioprotective effects.
• Inhibiting cFos diminished estrogen-induced β-arrestin1 increase in OVX rats.

Conclusions:

• Estrogen enhances β-arrestin1 expression mediated by cFos in the RVLM of postmenopausal rats.
• This mechanism alleviates sympathetic nerve hyperactivity and hypertension associated with menopause.