Regulation of gonadotropins by urocortin 2 in gonadotropic tumor LβT2 cells

LβT2 cells were found to express CRF1 receptor and CRF2 receptor mRNA. Ucn2 decreased CRF1 receptor mRNA levels, while it increased CRF2 receptor mRNA levels. Ucn2 directly decreased the mRNA levels of both luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in LβT2 cells. Ucn2 also decreased gonadotropin-releasing hormone receptor (GnRHR) mRNA levels. A selective CRF2 receptor antagonist suppressed the Ucn2-induced decreases in LH, FSH, and GnRHR mRNA levels. Ucn2 acts on gonadotrophs expressing the CRF2 receptor, and inhibits the production of gonadotropins in the pituitary gonadotropic tumor cells. (177 words)