|Jackson, Dahlia - UNIV OF MD EASTERN SHORE|
|Subbarathinam, R - UNIV OF MD EASTERN SHORE|
|Whitley, Niki - UNIV OF MD EASTERN SHORE|
Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: December 2, 2006
Publication Date: June 20, 2006
Citation: Jackson, D.J., Subbarathinam, R., Barb, C.R., Whitley, N.C. 2006. Influence of urocortin on luteinizing hormone (LH) release from porcine pituitary cells [abstract]. Journal of Animal Science Supplement. 85:(Suppl) p. 20. Technical Abstract: Pituitary cells from pre-pubertal gilts were used in two trials to determine the influence of urocortin (UCN) on LH secretion. Porcine pituitary cells were cultured at 100,000 cells/well in 24-well plates. On d 4 of culture in both trials, cells were challenged with 10, 1, or .1 nM UCN (U8, U9, U10, respectively); 1 nM LH-releasing hormone (LHRH) individually or in combination with 1 nM UCN (U9L). The T1 cells were also challenged with 1 nM LHRH/.1 nM UCN (U10L) while T2 cells were challenged with additional treatments of 1 or .10 nM UCN2 (U2-9 and U2-10) and 1 nM UCN3 (U3-9). Four to nine wells per treatment per pig were used in both trials. At 24 h after treatment, media were harvested and assayed for LH using RIA. For treated wells, LH secretion was expressed as a percentage of control and log transformed for analysis. Relative to the control (3.5 ± 0.5 and 7.2 ± 0.9 ng/ml for T1 and T2, respectively), U8, U9 and U10 increased (P < 0.05) LH secretion in T1 and U8 and U10 increased LH secretion in T2. In addition, LHRH and U9L increased (P < 0.01) LH secretion in both Trials and U10L increased (P < 0.01) LH secretion in T1. However, UCN did not alter LHRH-induced LH release in either trial. In T2, U3-10 increased (P < 0.001) LH but neither of the UCN2 concentrations used influenced LH secretion. These results indicate that UCN increased LH secretion directly at the level of the pituitary gland, but did not influence LHRH-induced LH secretion. Therefore UCN, which is secreted in response to stress, does not negatively impact pituitary LH release as seen with other stress hormones, but actually may play a role in the stress-induced increase in LH seen in peri-pubertal gilts.