Ovarian hormones modulate endothelin A and B receptor expression

Area of Science:

• Endocrinology
• Cardiovascular Physiology
• Renal Physiology

Background:

• Ovarian hormones, estrogen (E2) and progesterone (P), play crucial roles in physiological processes.
• Endothelin receptors, specifically ETA and ETB, are implicated in cardiovascular and renal functions.
• Sex differences in cardiovascular and renal diseases suggest hormonal influences on related signaling pathways.

Purpose of the Study:

• To investigate the modulatory effects of estrogen (E2) and progesterone (P) on endothelin A (ETA) and endothelin B (ETB) receptor expression.
• To determine these effects in key tissues including the lung, liver, and kidney.
• To elucidate the role of ovarian hormones in regulating ET receptor expression relevant to sex differences in health.

Main Methods:

• Female Sprague-Dawley rats underwent bilateral ovariectomy (OVX) or sham surgery.
• OVX rats were divided into groups receiving OVX, OVX+E2, OVX+P, or OVX+E2+P.
• ETA and ETB receptor expression in lung, liver, and kidney tissues was assessed using real-time PCR.

Main Results:

• Estrogen (E2) significantly reduced lung ETA receptor expression in OVX rats.
• Hepatic ETA and ETB receptors were increased in rats receiving both E2 and P compared to controls.
• Ovariectomy increased renal medullary ETA/ETB expression, an effect reversed by E2+P; renal cortical expression was reduced by OVX, but not by E2 treatment.

Conclusions:

• Ovarian hormones, estrogen and progesterone, significantly regulate ETA and ETB receptor expression in the lung, liver, and kidney.
• These hormonal modulations of ET receptors may contribute to observed sex differences in cardiovascular and renal health.
• The findings highlight a potential mechanism linking hormonal status to tissue-specific receptor expression and associated health outcomes.