Author
RICKES, E - MERCK RESEARCH LABS | |
CHANG, C - MERCK RESEARCH LABS | |
MCNAMARA, L - MERCK RESEARCH LABS | |
NARGUND, R - MERCK RESEARCH LABS | |
SMITH, R - MERCK RESEARCH LABS | |
Proudman, John | |
HICKEY, G - MERCK RESEARCH LABS |
Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only Publication Acceptance Date: 7/1/1998 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: The objective of this study was to investigate the activity of various GH secretagogues in male chicks. The GH secretagogues were selected on the basis of their EC50 as determined by an in-vitro rat pituitary cell assay. The EC50 of L-163,255, L-692,429 are 1.5, 3.0 and 60.0 nM, respectively. Ten day old Peterson x Arbor Acre male broilers or male H.L. W36 layer chicks were administered via i.v. injection, saline vehicle, L-692,585 at 10 or 50 ug/kg, L-692,429 at 50ug or 1mg/kg. Blood samples were taken at 15 and 30 minutes and plasma samples assay for GH levels. Intravenous administration of either L-692,585 or L-692,429 did not alter GH levels. L-163,255 at 50 ug and 1mg/kg was administered orally because of the high oral efficacy of this compound in other species. Fifteen minutes after oral administration L-162,255 at 50ug/kg or 1 mg/kg significantly increased GH in broilers (28.5+/-3.6, 33.7+/-3.6 ng/ml, P<0.05, respectively) when compared to vehicle control (17+/-3.6). L-162,255 in layers caused an increase in GH at 1 mg/kg, 72.7+/-5.4 ng/ml (P<0.01), when compared to the vehicle control (50+/-5.4) ng/ml). Results of this study suggests that both L-692,429 and L-692,585 at the doses given were not efficacious in stimulating GH response, while L-163,255 at the doses given was effective in stimulating GH response in male broiler and layer chicks. |