Local Regulatory Changes of <scp>HSD11B1</scp> and <scp>NR3C1</scp> in the Follicular and Luteal Tissue During Experimentally Induced Ovulation in the Cow

The objective of the study was to characterise the expression patterns of the two key components of cortisol action namely HSD11B1 (11-beta-hydroxysteroid dehydrogenase type 1) and NR3C1 (nuclear receptor subfamily 3, group C, member 1, also known as the glucocorticoid receptor) in superovulation induced bovine follicles during the periovulation and subsequent corpus luteum (CL) formation. Bovine ovaries containing preovulatory follicles or CL were timely defined during induced ovulation as follows: 0 h before GnRH (Gonadotropin-releasing hormone) application, and 4, 10, 20, 25 (follicles) and 60 h (early CL) after GnRH. The low mRNA expression of HSD11B1 and NR3C1 in the follicle group before the GnRH application increased significantly in the follicle group 20 h after GnRH and remained high afterward also in the early CL group. In contrast, the high NR3C1 mRNA decreased in follicles 25 h after GnRH (close to ovulation) and significantly increased again after ovulation (early CL). Our results indicated the involvement of HSD11B1 and NR3C1 as the two key components of cortisol action in the local mechanisms coordinating final follicle maturation, ovulation, follicular-luteal transition and CL development in the cow.