Nitric Oxide Synthase Activity and mRNA Expression in Chicken Macrophages 1

ABSTRACT The activity of inducible nitric oxide synthase (iNOS) enzyme was quantified in chicken macrophages. Macrophages from Cornell K-strain (B15B15), GB1 (B13B13), and GB2 (B6B6) chickens and a transformed cell line (MQ-NCSU) were incubated with or without varying concentrations of bacterial lipopolysaccharide (LPS). The culture supernatants were tested for the presence of nitrite. Macrophages from either source produced minimal nitrite (< 4.4 mM/1 × 106 cells) levels without LPS stimulation. However, nitrite levels produced by K-strain (42 mM) and MQ-NCSU (41 mM) macrophages were higher (P < 0.05) than those produced by the GB1 (14 mM) and GB2 (14 mM) per 1 × 106 macrophages with optimum LPS concentration range of 50 ng to 1 mg/mL. The addition of an Larginine analog, NGMMLA, at a concentration of 200 m