Parainfluenza-3 virus-induced enhancement of histamine release from calf lung mast cells--effect of levamisole.
Clinically healthy calves were divided into five groups. Group 1 served as control; Group 2 received levamisole (LEV), 3 mg/kg, s.c.; Group 3 was aerosolized with parainfluenza-3 virus (PI-3); Group 4 received LEV and PI-3 and Group 5 was inoculated with Pasteurella haemolytica. They were killed 6 days after virus exposure or 5-6 days after bacterial inoculation. Lung mast cells were prepared by enzymatic treatment. Mast cell histamine (HIST) release was assayed spectrofluorometrically. Total HIST (micrograms/g) in mast cells was as follows (means +/- SEM): control (5.30 +/- 0.26); LEV (5.27 +/- 0.31); PI-3 (6.37 +/- 0.65); LEV + PI-3 (6.21 +/- 0.51); P. haemolytica (7.06 +/- 0.85). Spontaneous HIST release was as follows (% total, means +/- SEM): control (10.38 +/- 1.09), LEV (11.95 +/- 2.13), PI-3v (73.57 +/- 11.97), PI-3v + LEV (19.50 +/- 3.03), and P. haemolytica (70.59 +/- 5.94). Calcium ionophore A23187 (5 X 10(-6) M)-induced release (% total, means +/- SEM) was: 51.53 +/- 3.05, 50.02 +/- 2.70, 83.91 +/- 4.09, 75.21 +/- 4.51 and 70.59 +/- 6.91 for control, LEV, PI-3, LEV + PI-3 and P. haemolytica groups, respectively. Both virus and bacteria increased HIST content of lung mast cells and enhanced ionophore-induced release. Levamisole significantly reduced spontaneous HIST release in virus-infected calves but had no effect on ionophore-induced release. Results suggest a significant role for HIST in pathogenesis of bovine microbial pneumonia and that LEV probably does not modulate non-immunologic release of HIST from bovine lungs.
Ogunbiyi
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Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Ontario, Canada.
Black
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Eyre
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D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D002417:Cattle; D002418:Cattle Diseases / Q000382:microbiology / Q000503:physiopathology*; D006636:Histamine Release / Q000187:drug effects*; D007978:Levamisole / Q000494:pharmacology*; D008168:Lung / Q000166:cytology; D008297:Male; D008407:Mast Cells / Q000187:drug effects* / Q000502:physiology; D010224:Parainfluenza Virus 3, Human; D018184:Paramyxoviridae Infections / Q000503:physiopathology / Q000662:veterinary*; D010326:Pasteurella Infections / Q000503:physiopathology / Q000662:veterinary
D007978:Levamisole; D000001:Calcimycin