The effects of dexamethasone on the response of bronchus-associated lymphoid tissue to intranasal administration of formalin-killed Pasteurella haemolytica A2 in goats.
A trial was conducted to observe the immediate and chronic effects in goats of dexamethasone administration on the bronchus-associated lymphoid tissue (BALT) response to intranasal administration of formalin-killed Pasteurella haemolytica A2. Twenty-four goats were divided into four groups. Those in group 1 were injected intramuscularly with 1 mg/kg dexamethasone on three consecutive days, followed by intranasal exposure to formalin-killed P. haemolytica A2 one day after the last dexamethasone treatment. The goats in group 2 were similarly injected with dexamethasone followed by intranasal exposure to formalin-killed P. haemolytica A2 21 days after the last dexamethasone treatment. The animals in group 3 were exposed intranasally to formalin-killed P. haemolytica A2 without prior dexamethasone treatment. The animals in group 4 were untreated controls. The intranasal exposures to formalin-killed P. haemolytica A2 were repeated 2 weeks later. Intranasal exposure to formalin-killed P. haemolytica 1 day after dexamethasone treatment further reduced the number and size of BALT compared to the untreated control. Significantly (p < 0.01) more reduction of BALT occurred in goats exposed to formalin-killed P. haemolytica A2 21 days after dexamethasone treatment. On the other hand, intranasal exposure of goats without prior dexamethasone treatment stimulated the BALT compared to the untreated controls.
Zamri-Saad
M
M
Faculty of Veterinary Medicine, Universiti Putra Malaysia, Selangor.
Effendy
A W
AW
D000281:Administration, Intranasal; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D001980:Bronchi / Q000187:drug effects* / Q000276:immunology / Q000382:microbiology; D003907:Dexamethasone / Q000494:pharmacology*; D005557:Formaldehyde; D015511:Goat Diseases / Q000276:immunology*; D006041:Goats; D008221:Lymphoid Tissue / Q000187:drug effects* / Q000276:immunology / Q000382:microbiology; D016978:Mannheimia haemolytica / Q000276:immunology*; D012766:Pasteurellosis, Pneumonic / Q000276:immunology*; D011897:Random Allocation
D000893:Anti-Inflammatory Agents; D005557:Formaldehyde; D003907:Dexamethasone