Induction of L-arginine-dependent production of nitric oxide in bovine monocytes by interferon gamma and lipopolysaccharide

Abstract

Bovine monocytes freshly isolated from peripheral blood were induced to produce nitric oxide by exposing them to recombinant bovine interferon gamma (rb ifn- y) and Escherichia coli lipopolysaccharide ( lps) in vitro. Moderate amounts of nitric oxide were induced by rb ifn-γ alone, but larger amounts were induced by rb ifn-γ and lps together, the amount being dependent on the quantity of rb ifn-γ added. Reactive nitrogen intermediates ( rni) were produced within six hours, their concentration peaked at four days and they were detectable for at least eight days after the cells had been stimulated with rb ifn- y and lps. The production of rni was diminished by the addition of N G-monomethyl-L-arginine. The data suggest that bovine monocytes can produce rni via a pathway involving an inducible nitric oxide synthase.