Influence of glucocorticoid on macromolecular absorption and passive immunity in neonatal lambs.
The relationship of serum cortisol to immunoglobulin absorption and gut closure in cesarean-derived neonatal lambs was evaluated in two trials. In trial 1, 21 lambs were obtained on d 136 to 138 of gestation, and in trial 2, 17 lambs were obtained on d 140 to 142 of gestation. At birth, lambs were assigned randomly to four treatments: 1) control (CO), 1 ml saline/kg BW every 4 h; 2) a drug to lower cortisol (LC), 5 mg metyrapone/kg BW every 4 h; 3) single-peak cortisol (SP), 10 IU ACTH/kg BW at 0 h; or 4) elevated cortisol (HC), 5 mg cortisol/kg BW every 4 h in trial 1 or 10 IU ACTH/kg BW every 4 h in trial 2. The treatment period was 24 and 48 h after delivery for trial 1 and 2, respectively. Lambs were fed pooled bovine colostrum every 4 h for 48 h after birth at 2 and 3.5% BW for trial 1 and 2, respectively. Compared with CO, HC increased serum cortisol, LC decreased serum cortisol and SP elevated serum cortisol concentrations through at least 8 h for both trials. In trial 1, HC and SP lambs exhibited elevated serum IgG, IgM and IgA concentrations by 20 h compared with CO. However, no difference in serum immunoglobulin concentration was observed at 36 h among CO, HC and SP. Conversely, LC had the lowest immunoglobulin concentration at 36 and 48 h, and precocious closure to immunoglobulin absorption had occurred by 20 h (P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)
Hough
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RL
Virginia Polytechnic Institute and State University, Blacksburg 24061.
McCarthy
F D
FD
Thatcher
C D
CD
Kent
H D
HD
Eversole
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DE
D000324:Adrenocorticotropic Hormone / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn / Q000276:immunology*; D002417:Cattle; D003126:Colostrum / Q000276:immunology; D006854:Hydrocortisone / Q000097:blood*; D007112:Immunity, Maternally-Acquired; D007136:Immunoglobulins / Q000378:metabolism*; D007408:Intestinal Absorption; D008797:Metyrapone / Q000494:pharmacology; D011897:Random Allocation; D012756:Sheep / Q000276:immunology*
D007136:Immunoglobulins; D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone; D008797:Metyrapone