Perinatal behavioral and immunological effects of prenatal diisopropyl fluorophosphate exposure in domestic fowl

Abstract

Experiment 1; Chick embryos received a single DFP exposure (0, 50, 100, 200, 400, 800, 1600, 3200 ]ig/kg) on embryogenesis day (E) 11. DFP was fatal to all embryos at 400 pg/kg and above, but did not affect hatch success at lower doses. Prenatal DFP reduced hatch weight and increased weight by posthatch day (PHD) 14. Prenatal DFP produced sex-and dose-dependent changes in distress vocalizations (DVs), but not activity on PHD 1. DFP increased tonic immobility duration (TI) on PHD 14. DFP increased lipopolysaccharide-induced lymphocyte proliferation in blood harvested on PHD 16 in females. Experiment 2: Daily DFP (0, 50, 100, or 200 pg/kg) on E 10-12 reduced hatch success. DFP reduced hatch weights in males, but not females. Prenatal DFP, 200 pg/kg, increased weight by PHD 14. DFP did not affect DVs, but increased activity in males at 50 pg/kg and females at 100 ug/kg on PHD 1. DFP increased TI in females, but not males, on PHD 14. DFP decreased pokeweed mitogen-induced and increased lipopolysaccaride-induced lymphocyte proliferation in blood and thymus (respectively) harvested on PHD 16. Experiment 3; Daily DFP (0, 100, or 200 iig/kg) on E 10-12 reduced hatch success, but did not affect weight at hatch or PHD 14. Chicks received 0.0, 0.5, or 1.5 mg/kg scopolamine 30 min before behavioral tests. Prenatal DFP vi (100 pg/kg) decreased DVs and 1.5 mg/kg scopolamine reversed the effect on PHD 1; there were no activity effects. Scopolamine, 0.5 mg/kg reduced TI except at 200 ug/kg DFP on PHD 14. Experiment 4: Daily DFP (0, 150, or 200 ]ig/kg) on E 10-12 did not affect hatch success or hatch weight, but increased weight by PHD 14. Chicks received 0.0, 0.25, or 0.5 mg/kg physostigmine 30 min before behavioral tests. On PHD 1, 0.25 physostigmine increased DVs in chicks at 150 Vig/kg DFP; activity was not affected. DFP increased TI in females, but not males, and PHY increased TI in females at 0 Vig/kg DFP on PHD 18. These data demonstrate perinatal consequences of prenatal DFP that endure into the third week posthatch and are sensitive to cholinergic manipulation. Ciinnick, Dr. Charles Drewes, Dr. Richard Hughes, Dr. Ronald Peters, and Dr. Robert Strahan for the guidance and assistance they have provided in the development of this dissertation. Additional thanks go to Dr. Cunnick for providing financial support for the purchase of the diisopropyl fluorophospate and the immune assays conducted by her laboratory. I also thank Hyline, Inc., Dallas Center, lA, for providing the fertile chicken eggs used in this study. I also thank Heidi Pierce, my colleague, for assisting me with this research and for providing feedback during development of this dissertation. Finally, special thanks go to Dr. Hughes, my major professor, mentor, and friend. His professional and personal support has been invaluable during my time here at Iowa State University.