Relationship Between Circulating Metabolic Hormones and Their Central Receptors During Ovariectomy-Induced Weight...

Area of Science:

• Endocrinology
• Neuroscience
• Metabolic Research

Background:

• Menopause is associated with body weight gain in women.
• Ovariectomy (OVX) in animal models rapidly induces weight gain, mimicking postmenopausal changes.
• Understanding the neuroendocrine regulation of weight is crucial.

Purpose of the Study:

• To investigate changes in ghrelin, insulin, and leptin receptor expression in specific brain regions (DVC, ARC, PVN) after OVX.
• To correlate these receptor changes with circulating hormone levels and body weight gain.
• To elucidate the role of central metabolic hormone signaling in post-ovariectomy weight gain.

Main Methods:

• Utilized ovariectomized (OVX) and sham-OVX female Sprague-Dawley rats.
• Measured body weight, plasma hormone levels (ghrelin, insulin, leptin), and receptor expression (ghrelin, insulin, leptin) in the DVC, ARC, and PVN at different time points post-surgery.
• Employed ELISA kits for quantitative analysis.

Main Results:

• OVX rats exhibited rapid body weight gain.
• Ghrelin receptor expression and circulating ghrelin levels remained unchanged.
• Insulin receptors decreased in the DVC and PVN of OVX rats, accompanied by elevated plasma insulin, indicating reduced insulin signaling.
• Leptin receptors increased in the PVN of sham rats but showed reduced signaling in the DVC, PVN, and ARC of OVX rats, despite elevated plasma leptin.

Conclusions:

• Post-ovariectomy weight gain is associated with altered insulin and leptin signaling in key CNS areas regulating appetite and metabolism.
• Ghrelin signaling appears unaffected in this model of weight gain.
• These neuroendocrine changes may contribute to or result from post-ovariectomy weight gain, warranting further investigation.