Background
Post-menopausal hypertension has been attributed solely to declining estrogen levels. The
Conclusions
Elevated FSH stimulates renin production involving a mechanism that may be relevant to the expression of FSH receptors in renal juxtaglomerular cells.
Methods
The expression of follicle stimulating hormone receptors (FSHRs) in renal juxtaglomerular cells and a As4.1 juxtaglomerular mouse cell line was evaluated. We established a mouse model by ovariectomy (OVX). Ovariectomized mice were treated with gonadotropin-releasing hormone agonist (GnRHa) (OVX + GnRHa). Ovariectomized mice initially received physiological doses of estrogen and were then injected with recombinant FSH (OVX + E + FSH).
Results
We found that FSHR was expressed in mouse renal juxtaglomerular cells labeled by renin antibody and in As4.1 cells. FSH promoted renin synthesis via Gsα-coupled FSHRs that activated protein kinase A, cyclic adenosine monophosphate(cAMP) response element-binding protein, extracellular signal-regulated kinase (Erk1/2), Protein kinase B(AKT), and c-Jun N-terminal kinase signaling pathways in As4.1 cells. We found increased serum FSH levels in the ovariectomized mouse with concurrent increases in renin, angiotensin II, heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial blood pressure (MAP). Additionally, increases in serum renin, angiotensin II, HR, SBP, DBP, and MAP were reduced by the additional injection of GnRHa. Exogenous FSH administration completely reversed decreases in renin, angiotensin II, HR, SBP, DBP, and MAP even in mice that received physiological doses of estrogen to maintain normal estradiol levels. Conclusions: Elevated FSH stimulates renin production involving a mechanism that may be relevant to the expression of FSH receptors in renal juxtaglomerular cells.