Related Experiment Video
Updated: Oct 5, 2026
Establishment of Rat Models Mimicking Gender-affirming Hormone Therapies
Published on: January 10, 2025
Moclobemide-induced gynecomastia in rats
1State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 200031, China.
Aim:
To study the toxic effect of moclobemide on male breast and to elucidate its mechanism of action.
Methods:
Routine histopathological analysis was used to diagnose the effect of moclobemide on male breast in rats. Plasma concentrations of estrogen, androgen, and prolactin were measured by a ratioimmunometer and relative receptors of mammary gland tissue were detected immunohistochemically.
Results:
After 180-d moclobemide treatment, the presence of gynecomastia was 0, 5, 5, 7/10 rats in 0, 60, 240, and 600 mg/kg groups, respectively. After 30-d convalescence, only one rat in 600 mg/kg group got the incidence of gynecomastia. Serum prolactin concentration had a trend to decrease with increasing dose and prolactin receptors in mammary gland were up-regulated.
Conclusion:
Long-term treatment with moclobemide causes gynecomastia in rats, which is reversible. The mechanism of moclobemide-induced gynecomastia may be related to the increase in prolactin receptors in mammary glands.
Related Concept Videos
01:22Hormonal Regulation of the Menstrual Cycle
At puberty, GnRH begins a pulsatile release pattern, which triggers the anterior pituitary gland to secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The frequency and amplitude of GnRH pulses vary across the menstrual cycle, with faster pulses favoring LH release and slower pulses favoring FSH release.
01:24Gonadal and Placental Hormones
In males, testosterone is the primary gonadal androgen. It plays a central role in the maturation of male reproductive organs — the penis and testes. Additionally, testosterone is instrumental in the development of secondary sexual characteristics — a deep voice as well as facial and pubic hair growth — and...