Impact of Physical Activity on Pain Perception in an Animal Model of Endometriosis

Abstract

Background Symptoms of endometriosis, such as pain and infertility, are considered significant sources of stress. In many chronic conditions, exercise can act as a stress buffer and influence pain perception. We tested the impact of swimming exercise on pain perception and pain receptors in an animal model of endometriosis. Methods Endometriosis (Endo) was induced in female rats by suturing uterine horn tissue next to the intestinal mesentery. Sham rats received sutures only. Rats were exposed to swimming exercise for 7 consecutive days, while no-exercise rats were left in the home cage. Fecal pellets were counted after swimming as an index of anxiety, and serum corticosterone levels measured. Pain perception was assessed using the hot plate test for hyperalgesia and Von Frey test for allodynia. Mu-opioid receptor (MOR) and neurokinin-1 receptor expression in the spinal cord was measured by immunofluorescence. Results Fecal pellet counts were higher in those animals that swam (p<0.05), but no significant difference in corticosterone was found. Although Endo-exercise rats had higher colonic damage (p<0.05) with more cellular infiltration, the lesions were smaller than in Endo–no exercise rats (p<0.05). Exercise did not ameliorate the hyperalgesia, whereas it improved allodynia in both groups. MOR expression was significantly higher in Endo-exercise vs. Endo–no exercise rats (p<0.01), similar to Sham–no exercise levels. Conclusions Our results point toward beneficial effects of swimming exercise during endometriosis progression. Physical interventions might be investigated further for their ability to reduce perceived stress and improve outcomes in endometriosis.

Antagonizing the corticotropin releasing hormone receptor 1 with antalarmin reduces the progression of endometriosis

“…The implants that developed into vesicles were excised from the mesentery, weighed and measured using a digital caliper. Classification of vesicles was carried out as previously described [ 26 , 36 ] and assigned the following grades: grade 1 = disappeared; grade 2 = 0.01–1.99 mm; grade 3 = 2–4.49 mm; grade 4 = 4.5–5.99 mm; grade 5 = 6.0 mm or larger. In sham animals, we counted and collected the empty suture sites.…”

Ovarian hormones modify anxiety behavior and glucocorticoid receptors after chronic social isolation stress

“…Three types of behaviors were analyzed: struggling, defined as a rapid movement in which the rat breaks the surface of the water with the forepaws; swimming, defined as horizontal movements across the surface of the water; and immobility defined as the absence of movement, except for those required to breathe and keep the head above the water. Depressive-like behaviors are characterized by an increase in immobility time and a decreased latency for immobility [38]. Behavior was recorded using a video camera located in front of the apparatus and analyzed with AnyMaze Software (Stoelting, Wood Dale, IL).…”

Environmental Manipulations as an Effective Alternative Treatment to Reduce Endometriosis Progression

“…10 Previous work from our group has demonstrated that stress can exacerbate the progression of endometriosis, 11 but its controllability can have beneficial effects. 12 In the clinical scenario, we and others have also demonstrated that endometriosis/dysmenorrhea causes an adaptive decrease in cortisol secretion once the disease has been established, pointing toward a malfunction of the hypothalamic-pituitary-adrenal (HPA) axis stress system. 13,14 Consequently, women with endometriosis might greatly benefit from alternative interventions that target stress reduction and promote well-being.…”