Environmental Enrichment Dampens the Increase in Glucocorticoid Receptors in the Hippocampus Caused by Endometriosis

Endometriosis is a disorder in which the development of uterine‐lining tissue is found outside the uterine cavity causing infertility, pain and stress. Previous studies have shown that stress can negatively affect the progression of the disease. Under the control of the hypothalamic pituitary adrenal (HPA) axis, circulating glucocorticoids regulate immune and stress responses by binding to the glucocorticoid receptors (GR). Our objective was to determine if GR is altered in the brain hippocampal area of rats with endometriosis. We focused on the hippocampus as this is one of the main brain areas that display GR. In addition, hippocampal GR play a significant role in HPA axis hyperactivity. Endometriosis was induced in female rats (n=16) by suturing uterine horn tissue next to the intestinal mesentery and the disease was allowed to progress for 60 days, during which rats were exposed to either environmental enriched conditions (increased social groups, larger enclosures, toys and nesting) or normal housing conditions. Sham rats (n=8) had only sutures in the intestinal mesentery and were exposed to normal housing conditions. At the time of sacrifice, endometriotic vesicles, uterus and brains were collected. A single labeling with DAB immunohistochemistry was performed to analyze the levels of GR in the Cornus amon (CA1 and CA3) and Dental Gyrus (DG) of the hippocampus. We have previously documented that environmental enrichment can significantly reduce the progression of endometriosis resulting also in decreased GR expression within endometriotic vesicles compared to nonenriched rats. Results show that rats with endometriosis had 60% increased GR integrated density in CA1 and DG regions of the rat hippocampus compared to sham controls. Non‐enriched animals had double the integrated density of GR in the dorsal CA3 compared to sham controls and this increase was dampened by environmental enrichment. Our data suggest that interventions that decrease stress can provide some benefit to return GR activity to baseline levels in both, peripheral tissues and also in brain structures involved in stress regulation. Support or Funding Information NIH‐K07AT008027 This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .