Submitted to: American Society of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: March 20, 1996
Publication Date: N/A
Technical Abstract: Infectious illness is associated with depressed thyrotroph and somatotroph function in humans and laboratory rodents. Such compromised endocrine function could exacerbate morbidity and mortality in neonatal pigs. Injections of LPS (150 g/kg, i.p.) or saline were administered to pigs at 1 (n=5 LPS, 5 saline), 21 (n=10 LPS, 10 saline), and 28 (n=13 LPS, 13 saline) )d of age. Pigs were sacrificed 3 hr post-injection for tissue collection. Serum samples were analyzed for concentrations of TNF-alpha, growth hormone (GH), thyroid-stimulating hormone (TSH), and prolactin (PRL). The secretion of TNF-alpha was increased by LPS injection. Serum TNF-alpha levels in the 1, 21, and 28-day-old animals were .39, .4, and .45 ng/ml in the saline- and .89, 1.83, and 1.45 ng/ml in the LPS-treated groups (LPS, p < .001; Age, p = .36; LPS X Age, p = .4; SE = .26). Circulating levels of GH and TSH were suppressed by LPS treatment. Serum GH concentrations at 1, ,21, and 28 d of age were 42.38, 23.35 and 12.62 ng/ml in the saline- and 41.52, 2.69, and 9.37 ng/ml in the LPS-injected groups (LPS, p < .05; Age, p < .0001; LPS X Age, p = .16; SE = 4.67). Corresponding concentrations of TSH were 2.1, 1.98, and 1.59 ng/ml in the saline- and 1.65, 1.67, and 1.53 ng/ml in the LPS-injected pigs (LPS, p < .01; Age, p < .014; LPS X Age, p = .26; SE = .11). In contrast with the effect of LPS exposure on GH and TSH secretion, PRL release was significantly increased. Serum concentrations of PRL at 1, 21, and 28 d of age were 3.94, 2.34, and 2.86 ng/ml in the control animals and 6.44, 3.46, and 4.49 in the LPS-injected animals (LPS, p < .0001; Age, p < .0001; LPS X Age, p < .27; SE = .35). This report demonstrates that neuroendocrine function in the neonatal pig can be influenced by an immunological challenge.