American journal of physiology. Endocrinology and metabolism
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Am. J. Physiol. Endocrinol. Metab. · Jul 2018
Low-dose brain estrogen prevents menopausal syndrome while maintaining the diversity of the gut microbiomes in estrogen-deficient rats.
We evaluated the effects of intracerebroventricular administration (ICV) of brain estrogen and progesterone on menopausal symptoms and their effects on the secretion of follicle-stimulating hormone(FSH) and luteinizing hormone (LH) in estrogen-deficient rats. Three weeks after ovariectomy (OVX) or sham operation, OVX rats were given ICV infusions of either 17β-estradiol (4 μg/day; ICV-E), progesterone(0.8 μg/day; ICV-P), or vehicle (control) for 4 wk. OVX rats in the positive-control group were orally provided 150 μg 17β-estradiol·kg body wt-1·day-1. ⋯ The control group exhibited decreased short-term memory and spatial memory compared with the other groups. Surprisingly, the control group exhibited a decreased richness of the gut microbiome compared with normal-control group, and ICV-E protected against the decrease the most. In conclusion, small amounts of brain estrogen and, to some extent, progesterone improved menopausal symptoms by decreasing serum FSH levels and maintaining the diversity of the gut microbiome in estrogen-deficient rats.