FIG 3.

Effect of 5-nitrouracil (5-NU) on the sensitivity of H. contortus larvae to naphthalophos (NAP). Larvae were treated with 5-NU (0.5, 1, or 2 mM) in the absence of phenobarbital (PHB) or in the presence of PHB at three concentrations (1, 2 or 4 mM). (A) No PHB; (B, C, and D) PHB at various concentrations. The key in panel A also applies to panels B and C. Each data point is the mean ± SE (n = 6; pooled data from three separate experiments, each with duplicate assays at each NAP concentration).