ARS | Publication request: ACTH INJECTIONS DURING GESTATION ALTER THE PIGLET'S HPA AXIS

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: April 24, 1999
Publication Date: N/A

Technical Abstract: Modern livestock production is potentially stressful due to confinement and crowding. When a pregnant sow is stressed, cortisol is released into the circulation and will cross the placenta to possibly affect the fetal hypothalamus. This study was designed to examine the physiology of piglets whose dams were injected with ACTH during gestation. Sixteen pregnant sows swere assigned to either the control group (C, n=8) or the ACTH injected group (A, n-8). The C sows were given no treatment while the A sows were administered an i.v. injection of ACTH (1 IU/kg of body weight) at 6, 7, 8, 9, 10, 11 and 12 wk of gestation. At birth, 1 mo and 2 mo of age piglets were weighed and one male of average weight was sacrificed. The hypothalamus, pituitary gland and adrenal glands were immediately obtained, weighed, and stored in liquid nitrogen. Hypothalamic CRH and beta-Endorphin, as well as mRNA for the adrenal ACTH receptor, were quantified. At 2.5 mo of age one pig from each litter was mixed with unfamiliar pigs and blood was obtained to determine plasma cortisol concentrations. Results indicate that A pigs tended to have larger pituitary glands than C pigs at 2 mo of age. The A pigs had greater mRNA for the ACTH receptor and concentrations of CRH than C pigs, but they had a lower concentration of beta-Endorphin. In response to mixing, A pigs had higher concentrations of plasma cortisol than C pigs. These results indicate that ACTH injections to sows during gestation alter the HPA axis of their offspring.