Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: April 15, 2004
Publication Date: September 16, 2004
Citation: Lay, Jr., D.C., Carroll, J.A., Weesner, G.D., Toscano, M.J., McMunn, K.A. 2004. Both psychological stress and physical stress alter the hypothalamic-pituitary-adrenal axis in swine [abstract]. International Journal of Psychophysiology. 54:190. Technical Abstract: Exposing pregnant mammals to prenatal stress has been shown to alter the stress response of their resulting offspring. Most stressors are a combination of psychological and physical stressors; therefore, we designed the following study to separate some of the confounding factors. Our objective was to determine which physiological factors, altered by prenatal stress, are due to the dam experiencing psychological stress versus physical stress. Sows treatments consisted of i.v. injections of adrenocorticotrophin (ACTH, 1 IU/kg BW) (ACTH, n = 11), exposure to rough handling for a 10-minute duration (ROU, n = 13), or no treatment (CONT, n = 13) once a week during d 42 to d 77 of gestation. Injections of ACTH were used to create a glucocorticoid response similar to a stressful situation, without causing the psychological stress assumed to result from the rough handling. Neuroendocrine tissue was collected from one male pig from each sow at 2 months of age and frozen: the hypothalamus for analysis of ß-endorphin and CRF, the anterior pituitary gland for POMC mRNA, and adrenal glands for the ACTH receptor mRNA. Pigs from dams who received ACTH during gestation had greater concentrations of CRF and ß-endorphin compared to pigs from control sows (.55 ± .11 vs. .29 ± .07, p < .006; 4.11 ± 1.07 vs. 1.60 ± .63, p < .02; respectively). In addition, pigs from roughly handled sows had greater ß-endorphin (3.12 ± .69, p < .02) and tended to have greater CRF (.35 ± .07, p < .07) than controls. Gene expression for POMC mRNA in the anterior pituitary gland and ACTH receptor mRNA in the adrenal gland did not differ among treatments (P < .30). These data indicate that the effects of prenatal stress are derived, in part, from direct activation of the hypothalamic-pituitary-adrenal axis. It is likely that severity and type of psychological stress will influence the degree to which prenatal stress effects are observed in offspring.