Mast cell dynamics in the ovary are governed by GnRH and prolactin

Endocrinology. 2023 Oct 5:bqad144. doi: 10.1210/endocr/bqad144. Online ahead of print.ABSTRACTGonadotrophin releasing hormone (GnRH) facilitates the migration of mast cells (MCs) into the involuting mammary gland. As GnRH is also expressed in the ovary, we examined changes in ovarian MCs. MCs in the ovary were mainly in interstitial tissue and their number increased during the estrous cycle to produce two peaks, one at diestrus 2 (20:00 h) and another at proestrus (17:00 h). Laser microdissection demonstrated that GnRH mRNA is expressed throughout ovarian tissues (corpora lutea, follicles and interstitial tissues). GnRH immunoreactivity was also ubiquitous, but MCs were most strongly immuno-stained. Analysis of GnRH mRNA in the ovary showed it to fluctuate similarly to the variation in MC number during the estrous cycle, and MCs also expressed GnRH. Local administration of a GnRH agonist (GnRHa) into the hemilateral ovarian bursa increased MCs in the administered ovary. MC number and GnRH mRNA were significantly lowered in the pregnant ovary. Prolactin administration suppressed the normal peaks in MC number in the ovary at both diestrus and proestrus. By contrast, a dopamine agonist, administered when prolactin was elevated during pseudopregnancy, increased ovarian MC number. Furthermore, prolactin inhibited GnRHa-induced peritoneal MC migration in a Transwell assay. These data clearly demonstrate that ovarian MC number is regulated positively by local GnRH expression and neg...
Source: Endocrinology - Category: Endocrinology Authors: Source Type: research