Levamisole-induced attenuation of alveolar macrophage dysfunction in respiratory virus-infected calves.
A luminol-amplified chemiluminescence (CL) assay was used to evaluate the effect of levamisole on the metabolic activity of pulmonary alveolar macrophages (PAM) from parainfluenza-3 (PI-3) and infectious bovine rhinotracheitis (IBR) virus-infected calves. Using selective beta-adrenergic agonists and antagonists, beta 1-adrenoceptors were shown to inhibit the PAM reactive oxygen species-dependent CL response. Beta 2 adrenoceptors were apparently not important in the regulation of CL in PAM of control calves. Infection of calves with IBR virus significantly impaired beta 1-receptor function. PI-3 virus infection, in addition to disrupting beta 1-receptors, also unmasked PAM beta 2-receptor activity. Treatment of calves with levamisole, 3 mg/kg, sub-cutaneously, partially reversed the virus-induced impairment of PAM beta 1-receptor function without influencing beta 2-receptor activity. In conclusion, beta-adrenoceptors regulate bovine PAM CL response. Pulmonary viruses impair PAM beta 1-receptor function, an action which can disrupt pulmonary homeostasis. Levamisole partially restores beta-receptor effects on PAM, and may therefore be useful in the management of virus-associated bacterial pneumonia.
Ogunbiyi
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PO
Department of Biomedical Sciences, University of Guelph, Ontario, Canada.
Conlon
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PD
Black
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WD
Eyre
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P
D000818:Animals; D002417:Cattle; D004195:Disease Models, Animal; D007241:Infectious Bovine Rhinotracheitis / Q000276:immunology*; D007978:Levamisole / Q000494:pharmacology*; D008163:Luminescent Measurements; D008264:Macrophages / Q000187:drug effects* / Q000276:immunology; D008297:Male; D010224:Parainfluenza Virus 3, Human; D018184:Paramyxoviridae Infections / Q000276:immunology*; D011650:Pulmonary Alveoli / Q000276:immunology*; D011943:Receptors, Adrenergic, beta / Q000502:physiology
D011943:Receptors, Adrenergic, beta; D007978:Levamisole