Optimization of assay conditions for leukotriene B4 synthesis by neutrophils or platelets isolated from peripheral blood of monogastric animals.

Neutrophils are involved in inflammation through leukotriene (LT) production. The predominant proinflammatory leukotriene released from neutrophils is LTB4, which serves as a biological marker of inflammation. The purpose of this study was to optimize the conditions ex vivo for LTB4 production by neutrophils from horses and dogs, and platelets from chickens. Optimal production of LTB4 was characterized by incubation time (2.5, 5, 10, 15 or 20 min), temperature (25 or 37 degrees C), and calcium ionophore A23187 concentration (0.1, 1, 10 or 20 microM). Incubation longer than 2.5 min did not increase production of LTB4 in chickens or horses; in dogs, incubation for 2.5 and 10 min resulted in the highest concentrations of LTB4 (P<or=0.05). In all species, incubation at 37 degrees C resulted in optimal LTB4 production (P<or=0.05). Production of LTB4 was highest when neutrophils or platelets were stimulated with 20 microM calcium ionophore in all species (P<or=0.05). These results indicate that neutrophils isolated from horses and dogs, and platelets isolated from chickens, are capable of producing LTB4. Optimum conditions for LTB4 production are similar in all three species.