Effect of Differential Embryonic Lead Exposure on Chicken Immune Function

s of papers 37 158 Effect of intra-abdominal injection of lipopolysaccharide or muramyl dipeptide on the acute phase response in Japanese quail (Coturnix coturnix japonica). E.A. Koutsos* and K.C. Klasing, University of California, Davis, California. Experiments were conducted in Japanese quail to determine the effect of repeated injections of lipopolysaccharide (LPS) from the cell wall of the gram-negative bacteria S. typhimurium, or muramyl dipeptide (MDP, NAcetylmuramyl-L-Ala-Isoglutamine) from the cell wall of gram-positive bacteria. Dose response trials (0.5, 1.0, 2.5, 7.5, 22.5 mg LPS/kg body weight) showed that 1.0 mg LPS/kg body weight or greater significantly increased body temperature, but there was no mortality at any dose. Doses of 0.3, 0.6, 1.2, 2.4, or 10 mg MDP/kg body weight caused no mortality or fever in Japanese quail. Further experiments revealed that an intra-abdominal injection of 7.5 mg LPS/kg body weight increased body temperature (p < .001) 5 hours post-injection, while 6.5 mg/kg body weight MDP caused no febrile response. The febrile response was diminished following a second injection of LPS 48 hours after the first, and a third injection had no effect. Plasma zinc, an acute phase response marker, was lowered (p < .001) in LPS and MDP injected birds after the first injection, but not after the second or third injection. Splenic interleukin 1-β (IL-1β) mRNA expression was increased after the first or third injection of LPS (p < .001), but only after the first injection of MDP (p < .005). Liver IL-1β mRNA was increased after the first, but not the third injection of LPS (p < .001), while MDP had no effect. These data indicate that Japanese quail are less sensitive to LPS than are chickens, MDP induced less of an acute phase response than LPS, and the febrile and liver IL-1β response to LPS was attenuated following the first injection.